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Makalah ini dibuat untuk memenuhi tugas Seminar Materi Tugas Akhir di Teknik Lingkungan ITB pada tahun 2011.
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SW4 - 1 EVALUATION OF LEACHATE TREATMENT PLANT IN SUWUNG LANDFILL DENPASAR CITY EVALUASI INSTALASI PENGOLAHAN LINDI DI TPA SUWUNG KOTA DENPASAR Camelia Indah Murniwati 1 and Tri Padmi 2 Department of Environmental Engineering Faculty of Civil Environmental Engineering, Institut Teknologi Bandung, Jl. Ganesha No. 10 Bandung 40132 1 [email protected] and 2 [email protected] Abstract: Suwung Landfill is a place of processing waste for Denpasar, Badung, Gianyar, and Tabanan areas. Suwung Landfill is in Desa Suwung Kauh, Kecamatan Denpasar Selatan. At the beginning, Suwung Landfill was operated with open dumping system but it will be operated with sanitary landfill system. Suwung Landfill has completed with leachate treatment plant with the configuration of plant is anaerobic ponds, facultative ponds, aerobic ponds, and constructed wetland. Each of leachate treatment unit in Suwung Landfill consists of two units, placed in parallel to each other. Based on calculation with Thornthwaite method, the quantity of leachate that entering the plant is 1.6 L/s. The result of leachate characteristics evaluation shows that in May 2011, effluent of leachate treatment plant did not comply to the quality standard for BOD, COD, TDS, TSS, and nitrite. After evaluated the leachate treatment design, seen that leachate treatment design in Suwung landfill does not comply to design criteria for depth, detention time, and organic loading rate. Key words : Aerobic pond, Anaerobic pond, Facultative pond, Constructed wetland, Leachate. Abstrak: TPA Suwung merupakan tempat pemrosesan akhir sampah yang ditujukan untuk wilayah Denpasar, Badung, Gianyar, dan Tabanan. TPA Suwung terletak di wilayah Desa Suwung Kauh, Kecamatan Denpasar Selatan. Awalnya, TPA Suwung beroperasi dengan sistem open dumping namun TPA Suwung akan dioperasikan dengan sistem sanitary landfill. TPA Suwung sudah dilengkapi dengan instalasi pengolahan lindi dengan konfigurasi unit pengolahan yang terdiri dari kolam anaerob, kolam fakultatif, kolam aerob, dan constructed wetland. Unit pengolahan lindi TPA Suwung masing-masing terdiri dari dua unit yang terletak paralel satu sama lain. Lindi yang masuk ke IPL berdasarkan perhitungan dengan metode Thornthwaite adalah 1,6 L/detik. Hasil evaluasi terhadap karakteristik lindi menunjukkan bahwa pada Mei 2011, efluen IPL tidak memenuhi baku mutu untuk parameter BOD, COD, TDS, TSS, dan nitrit. Setelah dilakukan evaluasi desain IPL, terlihat bahwa desain IPL TPA Suwung tidak sesuai dengan kriteria desain untuk parameter kedalaman, waktu detensi, dan organic loading rate. Kata kunci : Kolam aerob, Kolam anaerob, Kolam fakultatif, Constructed wetland, Lindi. INTRODUCTION The main problem encountered in the application of landfilling waste or other solid waste into the ground is the possibility of water pollution by leachate, the liquid waste arising from the entry of external water into the landfill (Damanhuri, 2008). Characteristics of leachate will depend on several things, such as the variety and proportion of waste components, rainfall and season, age of landfill, operational patterns, timing of sampling. Lu et al. (1984) in Qasim & Chiang (1994) reported that the concentration of pollutants in the leachate reach a peak in the early years (2 3 years), followed by a gradual decline in the next years. The ratio of BOD / COD decrease with increasing age of landfill. The ratio of BOD / COD show a declining from 0.47 to 0.07 over a period of 23 years (Miller et al., 1974 in Qasim & Chiang, 1994). Other data show the ratio of BOD / COD decrease from 0.8 to 0.05 over a period of 17 years (Chian & DeWalle, 1976 & 1977 in Qasim & Chiang, 1994).
Transcript
  • SW4 - 1

    EVALUATION OF LEACHATE TREATMENT PLANT

    IN SUWUNG LANDFILL DENPASAR CITY

    EVALUASI INSTALASI PENGOLAHAN LINDI

    DI TPA SUWUNG KOTA DENPASAR

    Camelia Indah Murniwati1 and Tri Padmi

    2

    Department of Environmental Engineering

    Faculty of Civil Environmental Engineering, Institut Teknologi Bandung,

    Jl. Ganesha No. 10 Bandung 40132 [email protected] and

    [email protected]

    Abstract: Suwung Landfill is a place of processing waste for Denpasar, Badung, Gianyar, and Tabanan areas.

    Suwung Landfill is in Desa Suwung Kauh, Kecamatan Denpasar Selatan. At the beginning, Suwung Landfill

    was operated with open dumping system but it will be operated with sanitary landfill system. Suwung Landfill

    has completed with leachate treatment plant with the configuration of plant is anaerobic ponds, facultative

    ponds, aerobic ponds, and constructed wetland. Each of leachate treatment unit in Suwung Landfill consists of

    two units, placed in parallel to each other. Based on calculation with Thornthwaite method, the quantity of

    leachate that entering the plant is 1.6 L/s. The result of leachate characteristics evaluation shows that in May

    2011, effluent of leachate treatment plant did not comply to the quality standard for BOD, COD, TDS, TSS, and

    nitrite. After evaluated the leachate treatment design, seen that leachate treatment design in Suwung landfill

    does not comply to design criteria for depth, detention time, and organic loading rate.

    Key words : Aerobic pond, Anaerobic pond, Facultative pond, Constructed wetland, Leachate.

    Abstrak: TPA Suwung merupakan tempat pemrosesan akhir sampah yang ditujukan untuk wilayah Denpasar,

    Badung, Gianyar, dan Tabanan. TPA Suwung terletak di wilayah Desa Suwung Kauh, Kecamatan Denpasar

    Selatan. Awalnya, TPA Suwung beroperasi dengan sistem open dumping namun TPA Suwung akan

    dioperasikan dengan sistem sanitary landfill. TPA Suwung sudah dilengkapi dengan instalasi pengolahan lindi

    dengan konfigurasi unit pengolahan yang terdiri dari kolam anaerob, kolam fakultatif, kolam aerob, dan

    constructed wetland. Unit pengolahan lindi TPA Suwung masing-masing terdiri dari dua unit yang terletak

    paralel satu sama lain. Lindi yang masuk ke IPL berdasarkan perhitungan dengan metode Thornthwaite adalah

    1,6 L/detik. Hasil evaluasi terhadap karakteristik lindi menunjukkan bahwa pada Mei 2011, efluen IPL tidak

    memenuhi baku mutu untuk parameter BOD, COD, TDS, TSS, dan nitrit. Setelah dilakukan evaluasi desain IPL,

    terlihat bahwa desain IPL TPA Suwung tidak sesuai dengan kriteria desain untuk parameter kedalaman, waktu

    detensi, dan organic loading rate.

    Kata kunci : Kolam aerob, Kolam anaerob, Kolam fakultatif, Constructed wetland, Lindi.

    INTRODUCTION

    The main problem encountered in the application of landfilling waste or other solid

    waste into the ground is the possibility of water pollution by leachate, the liquid waste arising

    from the entry of external water into the landfill (Damanhuri, 2008). Characteristics of

    leachate will depend on several things, such as the variety and proportion of waste

    components, rainfall and season, age of landfill, operational patterns, timing of sampling. Lu

    et al. (1984) in Qasim & Chiang (1994) reported that the concentration of pollutants in the

    leachate reach a peak in the early years (2 3 years), followed by a gradual decline in the next years. The ratio of BOD / COD decrease with increasing age of landfill. The ratio of

    BOD / COD show a declining from 0.47 to 0.07 over a period of 23 years (Miller et al., 1974

    in Qasim & Chiang, 1994). Other data show the ratio of BOD / COD decrease from 0.8 to

    0.05 over a period of 17 years (Chian & DeWalle, 1976 & 1977 in Qasim & Chiang, 1994).

  • SW4 - 2

    Leachate treatment system is needed to reduce the pollutant loading to receiving water

    bodies. Some landfill have included the leachate treatment facility as the must component. In

    general, the leachate treatment facility is the combination of stabilization ponds, filtration or

    sorption media, and land treatment or constructed wetland or other simple treatments. The

    result of monitoring conducted in some leachate treatment plant has not been able to conclude

    that the installation is functioning as expected, which may be caused by not taking the

    appropriate design criteria and operation of which has not been systematic (Damanhuri,

    2008).

    One landfill, equipped with leachate treatment plant is Suwung Landfill, Denpasar.

    The configuration of leachate treatment plant in Suwung landfill is anaerobic ponds,

    facultative ponds, aerobic ponds, and constructed wetland. The results of monitoring

    conducted at Suwung Landfill showed that the plant did not function as expected. Therefore,

    there should be an evaluation of the quantity and characteristics of leachate that is formed and

    the existing design of the leachate treatment plant.

    MATERIALS AND METHODS

    The methodology used to evaluate leachate treatment plant in Suwung Landfill can be

    seen in Figure 1.

    Figure 1 Materials and methods

    EXISTING CONDITION OF LEACHATE TREATMENT PLANT IN SUWUNG

    LANDFILL

    Leachate treatment plant of Suwung Landfill is at the lowest point of the landfill area

    thus the flow can be done by gravity. The plant consists of stabilization ponds and

    constructed wetland (Figure 2), each consist of two units located in parallel. A pond which

    located parallel to each other can increase the processing capacity (Naddafi, 2009).

    Figure 2 Configuration of leachate treatment plant in Suwung Landfill

    Stabilization ponds are rectangular with varying depths. The dimension of

    stabilization ponds can be seen in Table 1. Leachate treatment plant of Suwung Landfill is

    also completed with the constructed wetland. Constructed wetland is rectangular with three

    channels. The vegetation which is used is elephant grass (Penisetum purpureum). The

    dimension of constructed wetland can be seen in Table 2. However, there is not vegetation in

    Surveying and collecting the primary data

    Sampling and leachate

    characteristic testing at inlet

    and outlet

    Calculating the quantity of

    leachate with Thornthwaite

    Method

    Comparing the leachate

    treatment design with the design criteria

    Evaluating

  • SW4 - 3

    constructed wetland now. The filter of the constructed wetland is not working anymore so the

    constructed wetland is like a pond.

    Table 1 Dimension of stabilization ponds (As Built Drawing TPA Suwung, 2009) Parameter Anaerobic Pond Facultative Pond Aerobic Pond

    Length (m) 25 25 12.5

    Width (m) 20 15 7.95

    Depth (m) 2.5 0.4 0.75 1.4

    Length of baffle (m) 16

    Width of baffle (m) 0.2

    Quantity of baffle 4

    Quantity of compartment 5

    Length of compartment (m) 15

    Width of compartment (m) 4.5 4.75

    Table 2 Dimension of constructed wetland (As Built Drawing TPA Suwung, 2009) Parameter Value

    Length (m) 15.5

    Width (m) 10

    The thickness of the layer (m) :

    Top soil with elephant grass

    Marble stone / lime stone

    Soil

    0.30

    0.40

    0.60

    The quantity of divider channel 3

    EVALUATION OF LEACHATE TREATMENT PLANT IN SUWUNG LANDFILL

    Leachate Generation

    Leachate generation recalculates using the Thornthwaite Water Balance Method. The

    required data are climatological data and the design of landfill. The equation which is used is

    as follows:

    PERC = P RO AET - ST I = P RO APWL = NEG (I PET ) AET = PET + [(I PET) ST]

    Based on Table 3, the percolation of leachate into the solid waste (PERC) is 173

    mm/year. This value of PERC is used to know the leachate quantity from landfill by entering

    the value of PERC into the graphic of annual leachate quantities based on After Fenn et al.

    (1975) in Qasim & Chiang (1994). With the effective landfill area is 28 ha, the quantity of

    leachate (Q) is 50 x 106 L/year or 1.6 L/sec as shown in Figure 3.

    PERC : Percolation, mm

    P : Precipitation, mm

    RO : Run Off, mm

    AET : Actual Evapotranspiration, mm

    ST : Soil Moisture Storage month(n-1) - month(n), mm APWL : Accumulated Potential Water Loss, mm

    PET : Potential Evapotranspiration, mm

  • SW4 - 4

    Table 3 Calculations of leachate generation in Suwung Landfill with Thornthwaite Method Parameter Jan Feb Mar Apr May Jun Jul August Sep Oct Nov Des Total

    Temperatur 28.40 32.58 31.38 27.40 28.00 29.15 27.45 26.60 27.25 28.20 28.75 28.45

    Heat 13.87 17.08 16.13 13.14 13.58 14.43 13.17 12.56 13.03 13.72 14.13 13.91 168.74

    PET 174.36 326.29 274.93 148.04 163.43 196.38 149.28 129.31 144.38 168.82 184.38 175.76

    Daylight Factor 1.07 0.96 1.04 1.00 1.02 0.97 1.01 1.02 1.00 1.05 1.04 1.09

    PET Adjusted 186.56 313.24 285.93 148.04 166.69 190.49 150.77 131.90 144.38 177.26 191.76 191.58 2278.61

    P 405 331 194 116 76 41 22 6 24 131 227 318 1891

    CRO 0.125 0.125 0.125 0.125 0.125 0.125 0.125 0.125 0.125 0.125 0.125 0.125

    RO 51 41 24 15 10 5 3 1 3 16 28 40 236

    I 354 290 170 102 67 36 19 5 21 115 199 278 1655

    I - PET 168 -24 -116 -47 -100 -155 -132 -127 -123 -63 7 87

    APWL 0 -24 -140 -186 -287 -441 -573 -699 -823 -885 0 0

    ST 100 78 24 15 5 1 1 1 1 1 8 95

    ST -5 -22 -54 -9 -10 -4 0 0 0 0 7 87

    AET 187 312 224 111 77 40 19 5 21 115 192 192 1492

    PERC 173 0 0 0 0 0 0 0 0 0 0 0 173

    Figure 3 The Quantity of leachate

    Leachate Characterization

    The characteristics of leachate at inlet of leachate treatment plant can be seen in Table

    4. Analysis of leachate influent characteristics conducted by Puslitbang Permukiman

    Kementerian Pekerjaan Umum in December 2010 and is also directly analyzed in May 2011.

    The result of the test shows that the value of the leachate parameter in December 2010 is

    lower than in May 2011, especially for BOD and COD. It shows that the characteristics of

    leachate fluctuated. Leachate fluctuating conditions can be overcome by passing the leachate

    to the collecting pond before the leachate flows to the treatment pond to uniform the quantity

    and characteristics of the leachate.

    In December 2011, estimated that it is the rainy season, it is possible that the leachate

    has been diluted. BOD value is very low and it is not a typical value of BOD leachate in

    general. The range of leachate BOD value is 2,000 30,000 mg/L and COD value is 3,000 60,000 mg/L for leachate from new landfill, about 2 years old (Tchobanoglous, 1993 in

    Qasim & Chiang, 1994). If the condition of BOD and COD is low as BOD and COD in

    December 2011, the leachate does not need to pass through the anaerobic pond. Leachate can

    be directly channeled towards facultative pond with by pass channel. If BOD is high as in

    May 2011, leachate must be channeled through the anaerobic pond to reduce the BOD value.

    Value of BOD/COD in December 2010 is 0.88 so the leachate can be directly processed by

    biological processing. Meanwhile, in May 2011, the BOD/COD is 0.44 so that leachate can

    be directly processed by the biological treatment but need to be given additional nutrients.

    The leachate tends to be alkaline as typical of leachate in Indonesia but the pH value

    still at a pH range, suitable for biological life, 6 9. Leachate temperature is in the range of optimum temperature for activity of bacteria, 25 35oC. TDS and TSS value of leachate are

  • SW4 - 5

    relatively fresh in the range of 10,000 14,000 mg/L for TDS and 100-700 mg/L for TSS (Chian & Dewalle, 1976 in Qasim & Chiang, 1994). The ratio of BOD : N : P is 100 : 12.4 :

    0.02.

    Some of ammonia can be toxic to anaerobic bacteria so it can influence the removal

    of BOD and COD. Ammonia in the range 25 30 mg/L can cause 50% of bacterial growth obstructed. The high obstruction can happen when the concentration of ammonia is more than

    80 mg/L and can decrease significantly the removal of COD until 10%. In May 2011, the

    ammonia concentration of influent leachate treatment plant is 53,16 mg/L. That value causes

    the removal of BOD and COD is little obstructed.

    The leachate of Suwung Landfill also contain other contaminants such as chloride,

    sulphate, and metals. The content of chloride in leachate shows that leachate is from the new

    landfill, less than two years because the characteristics of leachate from the new landfill has a

    chloride content ranging from 200 3000 mg/L (Qasim & Chiang, 1994). Likewise, the parameter of sulphate that has a value of 50 1,000 mg/L in the leachate from the new landfill, leachate of Suwung Landfill closes to that range. SO4/Cl value is 0.76 indicating that

    the leachate from new landfill (less than two years).

    Table 4 IPL influent characteristics of Suwung Landfill Parameter Unit December 2010* May 2011

    TDS mg/L 4,180.40 13,161.78

    TSS mg/L 525.25 533.33

    Temperature oC 29.0 30.8

    Conductivity S/cm 22.81

    pH 7.60 8.04

    DO mg/L 1.75

    BOD mg/L 198.40 3,667.67

    COD mg/L 224.20 8,341.33

    Ammonium (NH4+N) mg/L 360.91

    Ammonia (NH3N) mg/L 19.75 53.16

    Nitrite (NO2-N) mg/L 4.00 1.77

    Nitrate (NO3-N) mg/L 16.20 20.26

    Organic Nitrogen mg/L 431.17

    TKN (NH3N) mg/L 484.33

    Total Phosphate (PO4-3P) mg/L 1.41

    Ortho Phosphate (PO4-3P) mg/L 0.81

    Sulphate mg/L 1,061.96

    Chloride mg/L 1,405.80

    Fe mg/L 4.10 36.90

    Cu mg/L 2.60

    Zn mg/L 6.70

    Cr mg/L 1.20

    Cd mg/L 0.16

    Pb mg/L 0.45 (*) Data of Puslitbang Permukiman Kementerian PU

    Performance of Leachate Treatment Plant

    The process in leachate treatment plant of Suwung Landfill is a biological process.

    Biological treatment stages include processing in anaerobic ponds, facultative ponds, aerobic

    ponds, and constructed wetland. At the inlet and outlet of each pond, the sampling is done to

    be tested so that the performance of the leachate treatment plant can be known. The value of

    the effluent parameter is compared with KEP-51/MENLH/10/1995 on wastewater quality

    standards class II.

    The optimum temperature for bacterial activity is between 25 35oC (Metcalf & Eddy, 2004). The temperature outside the optimum temperature will cause the treatment

    process is not running. The temperature of the leachate in leachate treatment plant is in the

    range of optimum temperature (Figure 4). The suitable pH for biological life is 6 9

  • SW4 - 6

    (Metcalf & Eddy, 2004). Leachate pH in the leachate treatment plant tends to be alkaline

    which is typical pH of leachate pH in Indonesia (Damanhuri, 2008). pH has met the quality

    standard (Figure 5).

    Figure 4 Condition of temperature Figure 5 Condition of pH

    The condition of TDS and TSS is shown in Figure 6 and Figure 7. The quality

    standard of TDS is 4000 mg/L. TDS in December 2010 is lower than TDS in May 2011. TDS

    in May 2011, reaching the peak value at the outlet of constructed wetland is 21,448.89 mg/L.

    Same with TDS, TSS in December 2010 is lower than TSS in May 2011. TSS value of

    leachate, reaching a peak in aerobic pond outlet is 1,538.22 mg/L. TSS value of constructed

    wetland at the outlet which has not met the quality standard is 792 mg/L. While the quality

    standard of TSS is 400 mg/L. Based on calculations, detention time in facultative ponds,

    aerobic ponds, and constructed wetland are very short and does not meet the design criteria.

    This is a possible cause of TSS values which do not meet quality standards. According to

    Machibya (2006), a short detention time will be set aside only large particles, whereas a

    longer detention time would set aside more of suspended particles.

    Figure 6 Condition of TDS Figure 7 Condition of TSS

    Organic parameter is indicated by the value of BOD and COD (Figure 8 and Figure

    9). Quality standard of BOD is 150 mg/L. The test result shows that BOD in December 2010

    is lower than BOD in May 2011. In December 2010, BOD value decreases until the end of

    treatment and has met the quality standard at the outlet of treatment plant, same with COD. In

    May 2011, BOD value decreases until facultative pond outlet and then increases at

    constructed wetland outlet. BOD value of the constructed wetland which has not met the

    quality standard is 603.33 mg/L. Likewise, the COD concentration tends to increase after

    passing through the constructed wetland. COD value of the constructed wetland is 1,468

    mg/L while the quality standard of COD is 300 mg/L. The increase in value also occurs in the

    parameter of TSS. This was probably caused by the absence of treatment plants in the land so

    there is not removal contaminant in it. In addition, there may be remnants of organic matter

    that is still contained in the media of constructed wetland that comes from the dead plants

    which cause the value of BOD, COD and TSS up back at the end of processing.

    26

    28

    30

    32

    34

    Anaerobic

    Influent

    Anaerobic

    Effluent

    Facultative

    Effluent

    Aerobic

    Effluent

    Constructed

    Wetland

    Effluent

    Tem

    pera

    ture (

    oC

    )

    Dec-10 May-11

    6

    7

    8

    9

    Anaerobic

    Influent

    Anaerobic

    Effluent

    Facultative

    Effluent

    Aerobic

    Effluent

    Constructed

    Wetland

    Effluent

    pH

    Dec-10 May-11

    0

    5000

    10000

    15000

    20000

    25000

    Anaerobic

    Influent

    Anaerobic

    Effluent

    Facultative

    Effluent

    Aerobic

    Effluent

    Constructed

    Wetland

    Effluent

    TD

    S (

    mg

    /L)

    Dec-10 May-11

    0

    500

    1000

    1500

    2000

    Anaerobic

    Influent

    Anaerobic

    Effluent

    Facultative

    Effluent

    Aerobic

    Effluent

    Constructed

    Wetland

    Effluent

    TS

    S (

    mg

    /L)

    Dec-10 May-11

  • SW4 - 7

    Figure 8 Condition of BOD Figure 9 Condition of COD

    The condition of nitrogen, including organic nitrogen, ammonia, nitrite, and nitrate in

    December 2010 and May 2011 are shown in Figure 10 to Figure 13. The high organic

    nitrogen at the beginning of the treatment shows that the leachate from landfill is new or fresh

    leachate. Ammonia contained in the leachate is from protein breakdown. Based on Kep-

    51/MENLH/10/1995 about wastewater quality standards class II, the quality standard for

    ammonia is 5 mg/L. Ammonia at the outlet of treatment in December 2010 and May 2011

    has met the quality standard. For nitrite, the required quality standard is 3 mg/L. In May 2011, the value of nitrite at the outlet of constructed wetland which has not met the quality

    standard is 10.22 mg/L. It is caused by the presence of factors that impede the course of

    nitrification. The factors that inhibit the nitrification is the number of active bacteria in nitrification is reduced in number, so that ammonia is converted to nitrite only and can not be

    resolved into the final product which is nitrate. Nitrate is a product resulting from the

    nitrification process. Therefore, nitrate can be used as indicators of the occurrence of

    nitrification process in the treatment process. In the water bodies, nitrate can stimulate

    eutrophication. Based on Kep-51/MENLH/10/1995 about wastewater quality standards class

    II, the quality standard of nitrate is 30 mg/L. Nitrate concentration decreases until the end of the treatment process. The value of nitrate at the outlet of constructed wetland has met the

    quality standard. The low content of ammonia, the high nitrite and the value of nitrate in the

    effluent shows that nitrification occurs in the leachate treatment plant.

    Figure 10 Condition of organic nitrogen Figure 11 Condition of ammonia

    Figure 12 Condition of nitrite Figure 13 Condition of nitrate

    0

    1000

    2000

    3000

    4000

    Anaerobic

    Influent

    Anaerobic

    Effluent

    Facultative

    Effluent

    Aerobic

    Effluent

    Constructed

    Wetland

    Effluent

    BO

    D (

    mg

    /L)

    Dec-10 May-11

    0

    2000

    4000

    6000

    8000

    10000

    Anaerobic

    Influent

    Anaerobic

    Effluent

    Facultative

    Effluent

    Aerobic

    Effluent

    Constructed

    Wetland

    Effluent

    CO

    D (

    mg

    /L)

    Dec-10 May-11

    0

    100

    200

    300

    400

    500

    600

    700

    Anaerobic

    Influent

    Anaerobic

    Effluent

    Facultative

    Effluent

    Aerobic

    Effluent

    Constructed

    Wetland

    Effluent

    Org

    an

    ic N

    itro

    gen

    (m

    g N

    H3-N

    /L)

    May-11

    0

    10

    20

    30

    40

    50

    60

    Anaerobic

    Influent

    Anaerobic

    Effluent

    Facultative

    Effluent

    Aerobic

    Effluent

    Constructed

    Wetland

    Effluent

    Am

    mon

    ia (

    mg

    NH

    3-N

    /L)

    Dec-10 May-11

    0

    2

    4

    6

    8

    10

    12

    Anaerobic

    Influent

    Anaerobic

    Effluent

    Facultative

    Effluent

    Aerobic

    Effluent

    Constructed

    Wetland

    Effluent

    Nit

    rit

    e (

    mg N

    O2-N

    /L)

    Dec-10 May-11

    0

    5

    10

    15

    20

    25

    Anaerobic

    Influent

    Anaerobic

    Effluent

    Facultative

    Effluent

    Aerobic

    Effluent

    Constructed

    Wetland

    Effluent

    Nit

    ra

    te (

    mg

    NO

    3-N

    /L)

    Dec-10 May-11

  • SW4 - 8

    Leachate from Suwung Landfill also contain metals. Conditions of iron can be seen in

    Figure 14. The quality standard of iron, based on Kep-51/MENLH/10/1995 is 10 mg/L. The value of iron decreases until the end of treatment. The effluent of constructed wetland already contains iron which is under the quality standard. Besides iron, leachate of Suwung Landfill also contains heavy metals such as Cu, Zn, Cr, Cd, Pb, shown in Table 5. After passing

    through series of treatment, the value of heavy metals in the outlet of leachate treatment plant

    has met the quality standard. The high concentration of metal ions are toxic to the species of Chlorella, the major species in stabilization ponds, and influence on the efficiency of the

    pond badly. However, a high pH value (more than 8) causes the metal ions precipitated and

    purification processes by ponds run normally again.

    Figure 14 Condition of Fe

    Table 5 Condition of heavy metals (Puslitbang Permukiman Kementerian PU, 2010)

    Parameter Cu Zn Cr Cd Pb

    Influent (mg/L) 2.6 6.7 1.2 0.16 0.45

    Efluent (mg/L) 0.78 1.1 0.56 0.044 0.095

    Quality Standard (mg/L) 3 10 1 0.1 1

    Configuration of Leachate Treatment Plant

    Configuration of leachate treatment plant that is used stabilization pond and

    constructed wetland should be the configuration in Figure 15. The configuration includes

    collecting pond, anaerobic pond, facultative pond, aerobic pond, and constructed wetland.

    Stabilization ponds can treat the high BOD with quite high efficiency, more economical, and

    easy in operation and maintenance. Stabilization ponds can be built with the material that is

    easy to get and in daily operation and it does not need skilled worker (Mozaheb, 2010).

    Besides reducing BOD, stabilization ponds also can reduce faecal coliform (Mohammed ,

    2006).

    Leachate treatment plant should be completed with collecting pond to mute the

    fluctuation of the charge and characteristics of leachate. Whereas, leachate treatment plant in

    Suwung Landfill is not completed with collecting pond. It causes the quantity and the

    characteristics of leachate that enter to the anaerobic pond fluctuate so the process in

    anaerobic pond is not optimal and the efficiency of pollutant removal is low.

    Stabilization ponds are often equipped with constructed wetland or constructed

    wetland. Constructed wetland can act to remove pollutants through bacterial activity, plant

    uptake, sedimentation, and filtration. Constructed wetland can also remove heavy metals such

    as Cr, Cu, Zn, and Pb with the efficiency of 30 80 % (Birch, 2004). Based on research by Nurulhuda (2010), constructed wetland with Cyperus papyrus as the vegetation can remove

    COD, BOD, NTK, TSS, color until 95.75%, 89.08%, 85.33%, 92.24%, 99%. Besides that,

    there is also removal of Fe, Cu, Zn until 91.38%, 98.15% dan 97.71% (Risnawati, 2010).

    0

    10

    20

    30

    40

    Anaerobic

    Influent

    Anaerobic

    Effluent

    Facultative

    Effluent

    Aerobic

    Effluent

    Constructed

    Wetland

    Effluent

    Fe (

    mg

    /L)

    Dec-10 May-11

  • SW4 - 9

    Figure 15 Suitable configuration of leachate treatment plant

    The Conformity of Leachate Treatment Design with The Design Criteria

    The design of each unit that exists such as anaerobic pond, facultative pond, aerobic

    pond, and constructed wetland is examined and compared with the design criteria.

    A. Anaerobic Pond The condition of anaerobic pond of leachate treatment plant in Suwung Landfill as follows :

    Length (p) = 25 m

    Width (l) = 20 m

    Depth (h) = 2.5 m

    Length of baffle = 16 m

    Width of baffle = 0.2 m

    Quantity of baffle = 4

    Leachate flow rate = 0.8 L/sec = 69.12 m3/day

    Concentration of BOD in (So) = 3,667.67 mg/L

    Concentration of BOD out (Se) = 3,020 mg/L The result of checking the dimensions of the anaerobic pond with the design criteria is shown

    in Table 6.

    Table 6 Comparison of anaerobic pond design and the design criteria Parameter Unit Existing

    Condition

    Design Criteria Info* Source

    Depth meter 2.5 2.5 5 V Qasim, 1985

    Min Detention Time day 17.6 2 5 V WHO, 1987

    Organic Loading Rate kg/m3.day 0.21 0.05 0.25 V WHO, 1987

    BOD Removal % 38.21 / 17.66 60 90 X Qasim, 1985 *V = comply with criteria

    X = not comply with criteria

    B. Facultative Pond The condition of facultative pond of leachate treatment plant in Suwung Landfill as follows :

    Length = 25 m

    Width = 15 m

    Quantity of compartment = 5

    Leachate flow rate = 0.8 L/sec = 69.12 m3/day

    Concentration of BOD in (So) = 3,020 mg/L

    Concentration of BOD out (Se) = 402 mg/L

    The dimensions of each compartment of facultative pond is shown in Table 7.

  • SW4 - 10

    Table 7 Dimension of facultative pond (As Built Drawing TPA Suwung, 2009) Parameter Compartment

    I II III IV V

    Length, m 15 15 15 15 15

    Width, m 4.75 4.5 4.5 4.5 4.75

    Depth, m 0.4 0.4 0.4 0.4 0.75

    Area, m2 71.25 67.5 67.5 67.5 71.25

    Volume, m3 28.5 27 27 27 28.5

    Even though, there are some methods to design facultative pond, Mara (1976) recommends to

    design based on surface BOD loading ( s, kg/ha.day). The results of checking the dimensions of the facultative pond with the design criteria is shown in Table 8.

    Table 8 Comparison of facultative pond design and the design criteria Parameter Unit Existing Condition Design Criteria Info* Source

    Depth meter 0.4 0.75 1 2 X Qasim, 1985

    Detention Time day 2 7 50 X Benefield & Randall, 1980

    Organic Loading Rate kg/ha.day 6,050.5 15 120 X Qasim, 1985

    BOD Removal % 5.30 / 86.69 70 95 X Benefield & Randall, 1980 *V = comply with criteria

    X = not comply with criteria

    C. Aerobic Pond The condition of aerobic pond of leachate treatment plant in Suwung Landfill as follows :

    Length (p) = 12.5 m

    Width (l) = 7.95 m

    Depth (h) = 1.4 m

    Leachate flow rate = 0.8 L/sec = 69.12 m3/day

    Concentration of BOD in (So) = 402 mg/L

    Concentration of BOD out (Se) = 401.33 mg/L

    BOD removal at aerobic pond or maturation pond is not too high but faecal bacteria removal

    is high (Mara, 2004). The calculation of aerobic pond design based on surface BOD loading.

    The result of checking the dimensions of aerobic pond with the design criteria is shown in

    Table 9.

    Table 9 Comparison of aerobic pond design and the design criteria Parameter Unit Existing

    Condition

    Design Criteria Info* Source

    Depth meter 1.4 0.3 1.0 X Qasim, 1985

    Detention Time day 2 5 20 X Qasim, 1985

    Organic Loading Rate kg/ha.day 2,691.25 40 120 X Qasim, 1985

    BOD Removal % 12.02 / 0.17 40 80 X Qasim, 1985 *V = comply with criteria

    X = not comply with criteria

    D. Constructed wetland The condition of constructed wetland of leachate treatment plant in Suwung Landfill as

    follows :

    Length (p) = 15.5 m

    Width (l) = 10 m

    Water depth = 1.5 m (from the bottom of the pond)

    Thickness of media (h) = 1.3 m (from the bottom of the pond), including: - Top soil with vegetation = 0.3 m

    - Marble stone / lime stone = 0.4 m

    - Soil = 0.6 m

  • SW4 - 11

    Vegetation = Elephant grass (Penisetum purpureum) Condition : not exist Leachate flow rate = 0.8 L/sec = 69.12 m3/day

    Concentration of BOD in (So) = 401.33 mg/L

    Concentration of BOD out (Se) = 603.33 mg/L The result of checking the dimensions of constructed wetland with the design criteria is

    shown in Table 10.

    Table 10 Comparison of constructed wetland design and the design criteria

    (subsurface flow constructed wetland) Parameter Unit Existing

    Condition

    Design Criteria Info* Source

    Detention Time day 1 3 4 (BOD) 6 10 (N)

    X Crites & Tchobanoglous, 1998

    Water Depth m 1.5 0.3 0.6 X Crites & Tchobanoglous, 1998

    Thickness of Media m 1.3 0.5 0.8 X Crites & Tchobanoglous, 1998

    BOD Loading kg/ha.day 1,789.67 < 112 X Crites & Tchobanoglous, 1998

    Hydraulic Loading m3/m2.day 0.446 0.015 0.05 X Metcalf & Eddy, 2004

    Specific Area ha/(103m3/day) 0.224 2.2 7.2 X Metcalf & Eddy, 2004

    BOD Removal % 9.35 / 0 65 88 X Crites & Tchobanoglous, 1998 *V = = comply with criteria X = not comply with criteria

    Based on checking of the leachate treatment design, it is seen that the organic loading

    rate of the facultative pond, aerobic ponds, and constructed wetland do not comply to the

    design criteria. It is caused by BOD inlet is still high and the leachate flow rate is more than

    the design capacity of leachate treatment plant. At constructed wetland, effluents BOD is higher than influents BOD. It happens because the constructed wetland has been saturated and the vegetation has die so adding the BOD concentration.

    THE SUGGESTION FOR THE IMPROVEMENT

    From the result of the evaluation of leachate generation, the characteristics of landfill

    leachate, and also the dimensions of each unit in the leachate treatment plant are proposed

    several suggestions for improvement including:

    The addition of equalization basin unit before the anaerobic pond unit. Equalization pond serves to reduce the variation of discharge and concentration of leachate entering the

    leachate treatment plant.

    The addition of by-pass channel that connects directly the equalization basin to the facultative pond without passing through the anaerobic pond. By pass channel brings the

    leachate directly to the facultative pond if the BOD of influent is low.

    Redesign the facultative pond unit and aerobic pond unit by adjusting the depth of the pond in accordance with the design criteria and expand the pond if the land is available or

    redesigning existing facultative pond becomes aerated facultative lagoon so that the

    treatment unit can process the leachate at the appropriate BOD loading.

    Redesign constructed wetland unit with the appropriate type of constructed wetland and selection of suitable plants for treating leachate.

  • SW4 - 12

    CONCLUSION

    The problem, found from the evaluation based on leachate effluent characteristics is

    the concentration of leachate fluctuates as shown by the different concentration of leachate in

    December 2010 and May 2011. In May 2011, the value of TDS, TSS, BOD, COD, and nitrite

    has not met the quality standard. The pollutant removal efficiency of leachate treatment plant

    at Suwung Landfill is low. Those are caused by the leachate treatment design which does not

    comply to the design criteria. The depth of the facultative pond and aerobic pond is not

    appropriate with the design criteria. In addition, leachate flow rate exceeds the design

    capacity of the leachate treatment plant so that the detention time in the leachate treatment

    pond is very short in the facultative pond and aerobic pond. It causes the processing in the

    pond is not optimal. Besides that, the constructed wetland does not function because the BOD

    loading is too high.

    REFERENCES

    Benefield & Randall. (1980). Biological Process Design for Wastewater Treatment. USA: Prentice-

    Hall, Inc.

    Birch, et al. (2004). Efficiency of a Constructed Wetland in Removing Contaminants from Stormwater.

    Journal of The Society of Wetland Scientists. Vol. 24. No. 2. pp 459 466. Crites & Tchobanoglous. (1998). Small and Decentralized Wastewater Management Systems.

    Singapore: McGraw-Hill, Inc.

    Damanhuri, Enri. (2008). Diktat Kuliah Landfill. Bandung: Teknik Lingkungan ITB.

    Kementerian Pekerjaan Umum. (2009). As Built Drawing TPA Suwung.

    Machibya, et al. (2006). Effect of Low Quality Effluent from Wastewater Stabilization Ponds to

    Receiving Bodies, Case of Kilombero Sugar Ponds and Ruaha river, Tanzania. International

    Journal of Environmental Research and Public Health. Vol. 3. No. 2. pp 209 216. Mara, Duncan. (2004). Domestic Wastewater Treatment in Developing Countries. UK: Cromwell

    Press.

    Metcalf & Eddy. (2004). Wastewater Engineering: Treatment and Reuse Fourth Edition. Singapore:

    McGraw-Hill, Inc.

    Mohammed. (2006). Design and Performance Evaluation of a Wastewater Treatment Unit. Journal of

    Departement of Agricultural Engineering, Federal University of Technology Minna, Niger

    State, Nigeria. Vol. 9. No. 3. pp. 193 198. Mozaheb, et al. (2010). Evaluation of Stabilization Ponds Performance for Municipal Wastewater

    Treatment in Yazd Iran. Middle-East Journal of Scientific Research. Vol. 6. No. 1. pp. 76 82.

    Naddafi, et al. (2009). Performance Evaluation of Wastewater Stabilization Ponds in Arak Iran. Iran Journal of Environmental Science and Engineering. Vol. 6. No. 1. pp. 41 46.

    Nurulhuda, Masayu. (2010). Penyisihan Senyawa Non Logam pada Lindi Menggunakan Constructed

    Wetland. Bandung: Tugas Akhir S1 Teknik Lingkungan ITB.

    Puslitbang Permukiman Kementerian Pekerjaan Umum. (2010). Hasil Pemeriksaan Lindi TPA

    Suwung Desember 2010.

    Qasim & Chiang. (1994). Sanitary Landfill Leachate. USA: Technomic Publishing Company, Inc.

    Qasim, Syed R. (1985). Wastewater Treatment Plant, Planning, Design, and Operational. New York:

    College Publishing.

    Risnawati, Imas. (2010). Penyisihan Logam pada Lindi Menggunakan Constructed Wetland.

    Bandung: Tugas Akhir S1 Teknik Lingkungan ITB.

    WHO. (1987). Wastewater Stabilization Ponds: Principles of Planning and Practice. Alexandria:

    WHO EMRO Technical Publication No. 10.

  • SW4 - 1

    EVALUASI INSTALASI PENGOLAHAN LINDI

    DI TPA SUWUNG KOTA DENPASAR

    EVALUATION OF LEACHATE TREATMENT PLANT

    IN SUWUNG LANDFILL DENPASAR CITY

    Camelia Indah Murniwati1 dan Tri Padmi

    2

    Program Studi Teknik Lingkungan

    Fakultas Teknik Sipil dan Lingkungan, Institut Teknologi Bandung,

    Jl. Ganesha No. 10 Bandung 40132 [email protected] dan [email protected]

    Abstrak: TPA Suwung merupakan tempat pemrosesan akhir sampah yang ditujukan untuk wilayah Denpasar,

    Badung, Gianyar, dan Tabanan. TPA Suwung terletak di wilayah Desa Suwung Kauh, Kecamatan Denpasar

    Selatan. Awalnya, TPA Suwung beroperasi dengan sistem open dumping namun TPA Suwung akan

    dioperasikan dengan sistem sanitary landfill. TPA Suwung sudah dilengkapi dengan instalasi pengolahan lindi

    dengan konfigurasi unit pengolahan yang terdiri dari kolam anaerob, kolam fakultatif, kolam aerob, dan

    constructed wetland. Unit pengolahan lindi TPA Suwung masing-masing terdiri dari dua unit yang terletak

    paralel satu sama lain. Lindi yang masuk ke IPL berdasarkan perhitungan dengan metode Thornthwaite adalah

    1,6 L/detik. Hasil evaluasi terhadap karakteristik lindi menunjukkan bahwa pada Mei 2011, efluen IPL tidak

    memenuhi baku mutu untuk parameter BOD, COD, TDS, TSS, dan nitrit. Setelah dilakukan evaluasi desain

    IPL, terlihat bahwa desain IPL TPA Suwung tidak sesuai dengan kriteria desain untuk parameter kedalaman,

    waktu detensi, dan organic loading rate.

    Kata kunci : Kolam aerob, Kolam anaerob, Kolam fakultatif, Constructed wetland, Lindi.

    Abstract: Suwung Landfill is a place of processing waste for Denpasar, Badung, Gianyar, and Tabanan areas.

    Suwung Landfill is in Desa Suwung Kauh, Kecamatan Denpasar Selatan. At the beginning, Suwung Landfill

    was operated with open dumping system but it will be operated with sanitary landfill system. Suwung Landfill

    has completed with leachate treatment plant with the configuration of plant is anaerobic ponds, facultative

    ponds, aerobic ponds, and constructed wetland. Each of leachate treatment unit in Suwung Landfill consists of

    two units, placed in parallel to each other. Based on calculation with Thornthwaite method, the quantity of

    leachate that entering the plant is 1,6 L/s. The result of leachate characteristics evaluation shows that in May

    2011, effluent of leachate treatment plant did not comply to the quality standard for BOD, COD, TDS, TSS, and

    nitrite. After evaluated the leachate treatment design, seen that leachate treatment design in Suwung landfill

    does not comply to design criteria for depth, detention time, and organic loading rate.

    Key words : Aerobic pond, Anaerobic pond, Facultative pond, Constructed wetland, Leachate.

    PENDAHULUAN

    Masalah utama yang dijumpai dalam aplikasi penimbunan atau pengurugan sampah

    atau limbah padat lainnya ke dalam tanah adalah kemungkinan pencemaran air oleh lindi,

    yaitu limbah cair yang timbul akibat masuknya air eksternal ke dalam timbunan sampah

    (Damanhuri, 2008). Karakteristik lindi akan tergantung dari beberapa hal, seperti variasi dan

    proporsi komponen sampah yang ditimbun, curah hujan dan musim, umur timbunan, pola

    operasional, waktu dilakukannya sampling. Lu et al. (1984) dalam Qasim & Chiang (1994)

    melaporkan bahwa konsentrasi polutan pada lindi mencapai puncak pada tahun-tahun awal

    yaitu pada usia landfill 2 3 tahun, diikuti dengan penurunan secara gradual pada tahun-tahun berikutnya. Rasio BOD/COD menurun dengan meningkatnya umur landfill. Rasio

    BOD/COD menunjukkan penurunan dari 0,47 0,07 selama periode 23 tahun (Miller et al., 1974 dalam Qasim & Chiang, 1994). Data lain menunjukkan rasio BOD/COD menunjukkan

  • SW4 - 2

    penurunan dari 0,8 0,05 selama periode 17 tahun (Chian & DeWalle, 1976 & 1977 dalam Qasim & Chiang, 1994).

    Pengadaan sistem pengolahan lindi sangat diperlukan untuk mengurangi beban

    pencemaran terhadap badan air penerima. Beberapa TPA telah mencantumkan sarana

    pengolahan lindi sebagai salah satu komponen wajibnya, dan umumnya berupa kombinasi

    kolam stabilisasi, media filtrasi atau sorpsi, dan lahan sanitasi atau pengolahan sederhana

    lainnya. Hasil pemantauan yang dilakukan di beberapa instalasi pengolahan lindi belum dapat

    menyimpulkan bahwa instalasi tersebut berfungsi sebagaimana yang diharapkan, yang

    mungkin disebabkan oleh pengambilan kriteria rancangan yang belum sesuai dan

    pengoperasian yang belum sistematis (Damanhuri, 2008).

    Salah satu Tempat Pemrosesan Akhir (TPA) sampah yang dilengkapi dengan

    Instalasi Pengolahan Lindi (IPL) adalah TPA Suwung, Kota Denpasar. Konfigurasi IPL TPA

    Suwung adalah kolam anaerob, kolam fakultatif, kolam aerob, dan constructed wetland. Hasil

    pemantauan yang dilakukan pada IPL TPA Suwung sebelumnya menyatakan bahwa instalasi

    tersebut belum berfungsi sebagaimana diharapkan. Oleh sebab itu, perlu dilakukan suatu

    evaluasi tentang kuantitas dan karakteristik lindi yang terbentuk serta desain IPL yang ada.

    METODOLOGI

    Metodologi yang digunakan untuk mengevaluasi IPL TPA Suwung dapat dilihat pada

    Gambar 1.

    Gambar 1 Metodologi

    KONDISI EKSISTING INSTALASI PENGOLAHAN LINDI TPA SUWUNG

    IPL TPA Suwung berada di titik terendah dari lokasi TPA dengan demikian

    pengalirannya dapat dilakukan secara gravitasi. Sistem pengolahan terdiri dari kolam

    stabilisasi dan constructed wetland (Gambar 2) yang masing-masing terdiri dari dua unit

    yang terletak secara paralel. Kolam yang terletak paralel satu sama lain dapat meningkatkan

    kapasitas pengolahan (Naddafi, 2009).

    Gambar 2 Konfigurasi IPL TPA Suwung

    Kolam stabilisasi berbentuk segi empat dengan kedalaman yang berbeda-beda.

    Dimensi kolam stabilisasi dapat dilihat pada Tabel 1. IPL TPA Suwung juga dilengkapi

    Survey dan pengumpulan data primer

    Sampling dan uji karakteristik lindi pada inlet dan outlet IPL

    Perhitungan debit lindi

    dengan Metode Thornthwaite

    Pengecekan desain IPL

    dengan kriteria desain

    Evaluasi

  • SW4 - 3

    dengan constructed wetland. Constructed wetland didesain berbentuk segi empat dengan tiga

    saluran pembagi. Vegetasi yang digunakan adalah rumput gajah (Penisetum purpureum).

    Dimensi constructed wetland dapat dilihat pada Tabel 2. Akan tetapi, vegetasi constructed

    wetland sudah tidak ada. Filter yang terdapat di dalam constructed wetland sudah tidak

    berfungsi lagi sehingga constructed wetland yang seharusnya kering menjadi menyerupai

    sebuah kolam.

    Tabel 1 Dimensi kolam stabilisasi (As Built Drawing TPA Suwung, 2009) Parameter Kolam Anaerob Kolam Fakultatif Kolam Aerob

    Panjang (m) 25 25 12,5

    Lebar (m) 20 15 7,95

    Kedalaman (m) 2,5 0,4 0,75 1,4

    Panjang bafel (m) 16

    Lebar bafel (m) 0,2

    Jumlah bafel 4

    Jumlah kompartemen 5

    Panjang tiap kompartemen (m) 15

    Lebar tiap kompartemen (m) 4,5 4,75

    Tabel 2 Dimensi constructed wetland (As Built Drawing TPA Suwung, 2009) Parameter Nilai

    Panjang (m) 15,5

    Lebar (m) 10

    Ketebalan lapisan (m) :

    Top soil dengan rumput gajah

    Batu marmer / batu kapur

    Tanah

    0,30

    0,40

    0,60

    Jumlah saluran pembagi 3

    EVALUASI INSTALASI PENGOLAHAN LINDI TPA SUWUNG

    Timbulan Lindi

    Timbulan lindi dihitung kembali dengan menggunakan Metode Neraca Air

    Thornthwaite. Data-data yang diperlukan yaitu data klimatologi dan data desain landfill.

    Persamaan yang digunakan adalah sebagai berikut :

    PERC = P RO AET - ST I = P RO APWL = NEG (I PET ) AET = PET + [(I PET) ST]

    Berdasarkan Tabel 3 didapat kesimpulan yaitu perkolasi lindi ke dalam tumpukan

    sampah (PERC) adalah 173 mm/tahun. Nilai PERC tersebut digunakan untuk mengetahui

    kuantitas lindi yang timbul dari landfill dengan memasukkan nilai PERC tersebut ke dalam

    grafik kuantitas lindi tahunan berdasarkan After Fenn et al. (1975) dalam Qasim & Chiang

    (1994). Dengan luas efektif TPA sebesar 28 ha, didapat kuantitas lindi (Q) sebesar 50 x 106

    L/tahun atau 1,6 L/detik seperti ditunjukkan pada Gambar 3.

    PERC : Perkolasi lindi ke dalam tumpukan sampah, mm

    P : Presipitasi, mm RO : Run off, mm

    AET : Aktual evapotranspirasi, mm

    ST : Soil Moisture Storage bulan ke-(n-1) dikurangi bulan ke-n, mm APWL : Accumulated Potential Water Loss, mm

    PET : Potensial evapotranspirasi, mm

  • SW4 - 4

    Tabel 3 Hasil perhitungan timbulan lindi dengan metode neraca air Thornthwaite Parameter Jan Feb Mar Apr Mei Jun Jul Agust Sep Okt Nov Des Jumlah

    Temperatur 28,40 32,58 31,38 27,40 28,00 29,15 27,45 26,60 27,25 28,20 28,75 28,45

    Heat 13,87 17,08 16,13 13,14 13,58 14,43 13,17 12,56 13,03 13,72 14,13 13,91 168,74

    PET 174,36 326,29 274,93 148,04 163,43 196,38 149,28 129,31 144,38 168,82 184,38 175,76

    Daylight Factor 1,07 0,96 1,04 1,00 1,02 0,97 1,01 1,02 1,00 1,05 1,04 1,09

    PET Adjusted 186,56 313,24 285,93 148,04 166,69 190,49 150,77 131,90 144,38 177,26 191,76 191,58 2278,61

    P 405 331 194 116 76 41 22 6 24 131 227 318 1891

    CRO 0,125 0,125 0,125 0,125 0,125 0,125 0,125 0,125 0,125 0,125 0,125 0,125

    RO 51 41 24 15 10 5 3 1 3 16 28 40 236

    I 354 290 170 102 67 36 19 5 21 115 199 278 1655

    I - PET 168 -24 -116 -47 -100 -155 -132 -127 -123 -63 7 87

    APWL 0 -24 -140 -186 -287 -441 -573 -699 -823 -885 0 0

    ST 100 78 24 15 5 1 1 1 1 1 8 95

    ST -5 -22 -54 -9 -10 -4 0 0 0 0 7 87

    AET 187 312 224 111 77 40 19 5 21 115 192 192 1492

    PERC 173 0 0 0 0 0 0 0 0 0 0 0 173

    Gambar 3 Kuantitas lindi

    Karakteristik Lindi

    Karakteristik lindi yang masuk ke dalam IPL dapat dilihat pada Tabel 4. Analisis

    karakteristik influen lindi dilakukan oleh Puslitbang Permukiman Kementerian Pekerjaan

    Umum pada Desember 2010 dan juga dianalisis langsung pada Mei 2011. Hasil pemeriksaan

    menunjukkan nilai parameter lindi pada Desember 2010 lebih rendah dari pada Mei 2011

    terutama untuk parameter BOD dan COD. Hal ini menunjukkan bahwa karakteristik lindi

    berfluktuasi. Kondisi lindi yang berfluktuasi ini dapat diatasi dengan mengalirkan lindi ke

    kolam penampung terlebih dahulu sebelum ke kolam pengolahan untuk menyeragamkan

    kuantitas dan karakteristik lindi.

    Pada Desember 2011 yang diperkirakan merupakan musim hujan, kemungkinan lindi

    yang masuk sudah mengalami pengenceran. Nilai BOD sangat rendah dan bukan merupakan

    tipikal BOD lindi TPA pada umumnya. Kisaran nilai BOD lindi adalah 2.000 30.000 mg/l dan kisaran nilai COD adalah 3.000 60.000 mg/l untuk lindi yang berasal dari landfill baru atau berusia sekitar 2 tahun (Tchobanoglous, 1993 dalam Qasim & Chiang, 1994). Jika

    kondisi BOD dan COD rendah seperti pada Desember 2011 maka lindi yang masuk ke IPL

    tidak perlu melewati kolam anaerob. Lindi tersebut bisa langsung dialirkan menuju kolam

    fakultatif dengan melewati saluran by pass. Jika nilai BOD tinggi seperti pada Mei 2011,

    lindi harus dialirkan melewati kolam anaerob terlebih dahulu untuk menurunkan nilai BOD.

    Nilai BOD/COD pada Desember 2010 adalah 0,88 sehingga lindi bisa langsung diolah

    dengan pengolahan biologi. Sedangkan pada Mei 2011, BOD/COD adalah 0,44 sehingga

    lindi dapat langsung diolah dengan pengolahan biologis tetapi perlu diberi tambahan nutrien.

    Sifat lindi cenderung basa yang merupakan tipikal lindi di Indonesia namun nilai pH

    masih berada pada rentang pH yang cocok untuk kehidupan biologi yaitu 6 9. Temperatur

  • SW4 - 5

    lindi berada pada kisaran temperatur optimum untuk akivitas bakteri yaitu 25 35oC. Nilai TDS dan TSS lindi tergolong segar yaitu berada pada kisaran 10000 14000 mg/L untuk TDS dan 100 700 mg/L untuk TSS (Chian & Dewalle, 1976 dalam Qasim & Chiang, 1994). Perbandingan BOD : N : P adalah 100 : 12,4 : 0,02.

    Konsentrasi amoniak tertentu dapat bersifat toksik terhadap bakteri anaerob sehingga

    dapat mempengaruhi penyisihan BOD dan COD. Kisaran konsentrasi amoniak 25 30 mg/L dapat menyebabkan 50 % pertumbuhan bakteri terhambat. Hambatan amoniak yang kuat

    dapat terjadi pada konsentrasi amoniak lebih dari 80 mg/L dan dapat mengurangi secara

    signifikan penyisihan COD hanya mencapai 10 %. Kadar amoniak influen IPL pada Mei

    2011 mencapai 53,16 mg/L. Nilai tersebut menyebabkan penyisihan BOD dan COD sedikit

    terhambat.

    Lindi TPA Suwung juga mengandung pencemar lain seperti klorida, sulfat, dan

    logam. Kandungan klorida pada lindi menunjukkan bahwa lindi tersebut berasal dari

    timbunan sampah yang berusia kurang dari dua tahun karena karakteristik lindi dari landfill

    baru memiliki kandungan klorida yang berkisar antara 200 3.000 mg/l (Qasim & Chiang, 1994). Demikian juga dengan parameter sulfat yang memiliki nilai 50 1000 mg/L pada lindi yang berasal dari landfill baru, lindi TPA Suwung mendekati rentang tersebut. Nilai SO4/Cl

    adalah 0,76 yang menunjukkan bahwa lindi berasal dari landfill baru (kurang dari dua tahun).

    Tabel 4 Karakteristik influen IPL TPA Suwung Parameter Satuan Desember 2010* Mei 2011

    TDS mg/L 4.180,40 13.161,78

    TSS mg/L 525,25 533,33

    Temperatur oC 29,0 30,8

    DHL S/cm 22,81

    pH 7,60 8,04

    DO mg/L 1,75

    BOD mg/L 198,40 3.667,67

    COD mg/L 224,20 8.341,33

    Amonium (NH4+N) mg/L 360,91

    Amoniak (NH3N) mg/L 19,75 53,16

    Nitrit (NO2-N) mg/L 4,00 1,77

    Nitrat (NO3-N) mg/L 16,20 20,26

    Nitrogen Organik mg/L 431,17

    NTK (NH3N) mg/L 484,33

    Total Fosfat (PO4-3P) mg/L 1,41

    Ortho Fosfat (PO4-3P) mg/L 0,81

    Sulfat mg/L 1.061,96

    Klorida mg/L 1.405,80

    Fe mg/L 4,10 36,90

    Cu mg/L 2,60

    Zn mg/L 6,70

    Cr mg/L 1,20

    Cd mg/L 0,16

    Pb mg/L 0,45 (*) Data Puslitbang Permukiman Kementerian PU

    Kinerja Instalasi Pengolahan Lindi

    Pengolahan yang dilakukan pada IPL adalah pengolahan secara biologis. Tahapan

    pengolahan biologis tersebut meliputi pengolahan pada kolam anaerob, kolam fakultatif,

    kolam aerob, dan constructed wetland. Pada inlet dan outlet masing-masing kolam

    pengolahan dilakukan pengambilan sampel untuk diuji karakteristiknya sehingga dapat

    diketahui kinerja IPL. Nilai setiap parameter efluen IPL dibandingkan dengan baku mutu

    KEP-51/MENLH/10/1995 tentang baku mutu limbah cair golongan II.

    Temperatur optimum untuk aktivitas bakteri berkisar antara 25 35oC (Metcalf & Eddy, 2004). Temperatur di luar temperatur optimum akan menyebabkan proses pengolahan

  • SW4 - 6

    tidak berjalan. Temperatur lindi pada IPL berada di dalam kisaran temperatur optimum

    (Gambar 4). pH yang cocok untuk kehidupan biologi berkisar antara 6 9 (Metcalf & Eddy, 2004). pH lindi pada IPL cenderung basa yang merupakan tipikal pH lindi di Indonesia

    (Damanhuri, 2008). pH tersebut sudah memenuhi baku mutu (Gambar 5).

    Gambar 4 Kondisi temperatur Gambar 5 Kondisi pH

    Kondisi TDS dan TSS ditunjukkan pada Gambar 6 dan Gambar 7. Baku mutu TDS

    adalah 4000 mg/L. Nilai TDS lindi pada bulan Desember 2010 lebih rendah dari pada TDS

    lindi di bulan Mei 2011. Pada Mei 2011, TDS mencapai puncak pada outlet kolam

    constructed wetland yaitu 21.448,89 mg/l. Demikian halnya dengan kondisi TSS, nilai TSS

    lindi pada bulan Desember 2010 lebih rendah dari pada TSS lindi di bulan Mei 2011. Pada

    Mei 2011, nilai TSS lindi mencapai puncak pada outlet kolam aerob yaitu 1.538,22 mg/L dan

    nilai TSS lindi pada outlet constructed wetland belum memenuhi baku mutu yaitu 792 mg/L.

    Sedangkan baku mutu TSS adalah 400 mg/L. Berdasarkan perhitungan, waktu detensi pada

    kolam fakultatif, kolam aerob, dan constructed wetland sangat singkat dan tidak memenuhi

    kriteria desain. Hal tersebut yang kemungkinan menyebabkan nilai TSS belum memenuhi

    baku mutu. Menurut Machibya (2006), waktu detensi yang singkat hanya akan menyisihkan

    partikel besar, sedangkan waktu detensi yang lebih lama akan menyisihkan lebih banyak

    partikel tersuspensi.

    Gambar 6 Kondisi TDS Gambar 7 Kondisi TSS

    Parameter organik ditunjukkan dengan nilai BOD dan COD (Gambar 8 dan Gambar

    9). Baku mutu BOD adalah 150 mg/L. Hasil pemeriksaan menunjukkan nilai BOD lindi pada

    bulan Desember 2010 lebih rendah dari pada BOD lindi di bulan Mei 2011. Pada Desember

    2010, nilai BOD lindi menurun sampai akhir pengolahan dan sudah memenuhi baku mutu di

    outletnya demikian halnya dengan nilai COD. Pada Mei 2011, nilai BOD menurun sampai

    outlet kolam fakultatif dan naik kembali pada outlet constructed wetland. Nilai BOD pada

    outlet constructed wetland belum memenuhi baku mutu yaitu 603,33 mg/L. Demikian juga

    dengan parameter COD yang cenderung naik kembali konsentrasinya setelah melewati

    constructed wetland. Nilai COD pada outlet constructed wetland yaitu 1.468 mg/L.

    Sedangkan baku mutu COD yang disyaratkan adalah 300 mg/L. Kenaikan nilai konsentrasi

    juga terjadi pada parameter TSS. Hal ini kemungkinan disebabkan oleh sudah tidak adanya

    tumbuhan di dalam constructed wetland sehingga penyisihan pencemar tidak terjadi. Selain

    itu, kemungkinan terdapat sisa-sisa materi organik yang masih terkandung di dalam media

    27

    28

    29

    30

    31

    32

    33

    Influen

    Anaerob

    Efluen

    Anaerob

    Efluen

    Fakultatif

    Efluen

    Aerob

    Efluen

    Constructed

    Wetland

    Tem

    pera

    tur (

    oC

    )

    Des-10 Mei-11

    6

    7

    8

    9

    Influen

    Anaerob

    Efluen

    Anaerob

    Efluen

    Fakultatif

    Efluen

    Aerob

    Efluen

    Constructed

    Wetland

    pH

    Des-10 Mei-11

    0

    5000

    10000

    15000

    20000

    25000

    Influen

    Anaerob

    Efluen

    Anaerob

    Efluen

    Fakultatif

    Efluen

    Aerob

    Efluen

    Constructed

    Wetland

    TD

    S (

    mg

    /L)

    Des-10 Mei-11

    0

    500

    1000

    1500

    2000

    Influen

    Anaerob

    Efluen

    Anaerob

    Efluen

    Fakultatif

    Efluen

    Aerob

    Efluen

    Constructed

    Wetland

    TS

    S (

    mg

    /L)

    Des-10 Mei-11

  • SW4 - 7

    constructed wetland yang berasal dari sisa-sisa tumbuhan yang mati yang menyebabkan nilai

    BOD, COD, dan TSS naik kembali di akhir pengolahan.

    Gambar 8 Kondisi BOD Gambar 9 Kondisi COD

    Kondisi parameter nitrogen yaitu nitrogen organik, amoniak, nitrit, dan nitrat pada

    Desember 2010 dan Mei 2011 ditunjukkan pada Gambar 10 13. Nitrogen organik yang tinggi di awal pengolahan menunjukkan bahwa lindi berasal dari landfill yang masih baru

    atau lindi segar. Amoniak yang terdapat dalam air lindi berasal dari pemecahan protein.

    Berdasarkan Kep-51/MENLH/10/1995 tentang baku mutu limbah cair golongan II, baku

    mutu amoniak adalah 5 mg/L. Amoniak pada Desember 2010 dan Mei 2011 sudah memenuhi

    baku mutu di outlet pengolahan. Untuk nitrit, baku mutu yang disyaratkan adalah 3 mg/L.

    Pada Mei 2011, nilai nitrit pada outlet constructed wetland belum memenuhi baku mutu yaitu

    10,22 mg/L. Hal ini disebabkan oleh adanya faktor-faktor yang menghambat jalannya

    nitrifikasi. Faktor yang menghambat antara lain jumlah bakteri yang aktif melakukan

    nitrifikasi berkurang jumlahnya, sehingga amoniak hanya diubah menjadi nitrit dan tidak

    dapat diselesaikan menjadi produk akhir berupa nitrat. Nitrat merupakan produk yang

    dihasilkan dari proses nitrifikasi. Oleh karena itu, nitrat dapat dijadikan indikator terjadinya

    proses nitrifikasi pada proses pengolahan. Pada badan air, nitrat akan menstimulasi

    eutrofikasi. Berdasarkan Kep-51/MENLH/10/1995 tentang baku mutu limbah cair golongan

    II, baku mutu nitrat adalah 30 mg/L. Kadar nitrat tersebut menurun sampai akhir pengolahan.

    Nilai nitrat pada outlet constructed wetland sudah memenuhi baku mutu. Kandungan

    amoniak yang rendah, tingginya nilai nitrit dan adanya nitrat pada efluen menunjukkan

    bahwa nitrifikasi terjadi pada unit IPL.

    Gambar 10 Kondisi nitrogen organik Gambar 11 Kondisi amoniak

    Gambar 12 Kondisi nitrit Gambar 13 Kondisi nitrat

    0

    1000

    2000

    3000

    4000

    Influen

    Anaerob

    Efluen

    Anaerob

    Efluen

    Fakultatif

    Efluen

    Aerob

    Efluen

    Constructed

    Wetland

    BO

    D (

    mg

    /L)

    Des-10 Mei-11

    0

    2000

    4000

    6000

    8000

    10000

    Influen

    Anaerob

    Efluen

    Anaerob

    Efluen

    Fakultatif

    Efluen

    Aerob

    Efluen

    Constructed

    Wetland

    CO

    D (

    mg

    /L)

    Des-10 Mei-11

    0

    200

    400

    600

    800

    Influen

    Anaerob

    Efluen

    Anaerob

    Efluen

    Fakultatif

    Efluen Aerob Efluen

    Constructed

    Wetland

    N. O

    rga

    nik

    (m

    g N

    H3-

    N/L

    )

    Mei-11

    0

    20

    40

    60

    Influen

    Anaerob

    Efluen

    Anaerob

    Efluen

    Fakultatif

    Efluen Aerob Efluen

    Constructed

    Wetland

    Am

    on

    iak

    (m

    g N

    H3-

    N/L

    )

    Des-10 Mei-11

    0

    2

    4

    6

    8

    10

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    Influen

    Anaerob

    Efluen

    Anaerob

    Efluen

    Fakultatif

    Efluen Aerob Efluen

    Constructed

    Wetland

    Nit

    rit

    (m

    g N

    O2-N

    /L)

    Des-10 Mei-11

    0

    5

    10

    15

    20

    25

    Influen

    Anaerob

    Efluen

    Anaerob

    Efluen

    Fakultatif

    Efluen

    Aerob

    Efluen

    Constructed

    Wetland

    Nit

    ra

    t (m

    g N

    O3-N

    /L)

    Des-10 Mei-11

  • SW4 - 8

    Lindi yang berasal dari TPA Suwung juga mengandung logam. Kondisi logam besi

    dapat dilihat pada Gambar 14. Baku mutu besi adalah 10 mg/L. Nilai besi menurun sampai

    akhir pengolahan. Efluen constructed wetland sudah mengandung besi yang berada di bawah

    baku mutu. Selain logam besi, lindi IPL TPA Suwung juga mengandung logam berat Cu, Zn,

    Cr, Cd, Pb yang ditunjukkan pada Tabel 5. Setelah melalui serangkaian pengolahan, nilai

    logam berat lindi pada outlet IPL sudah memenuhi baku mutu. Konsentrasi yang tinggi dari

    ion metal bersifat toksik terhadap spesies Chlorella, spesies utama di dalam kolam stabilisasi,

    dan mempengaruhi secara buruk terhadap efisiensi kolam. Akan tetapi, nilai pH yang tinggi

    (lebih dari 8) menyebabkan ion metal mengalami presipitasi dan proses penjernihan dengan

    kolam dapat berjalan normal kembali.

    Gambar 14 Kondisi besi

    Tabel 5 Kondisi logam berat (Puslitbang Permukiman Kementerian PU, 2010)

    Parameter Cu Zn Cr Cd Pb

    Influen IPL (mg/L) 2,6 6,7 1,2 0,16 0,45

    Efluen IPL (mg/L) 0,78 1,1 0,56 0,044 0,095

    Baku Mutu (mg/L) 3 10 1 0,1 1

    Konfigurasi Instalasi Pengolahan Lindi

    Konfigurasi IPL dengan menggunakan kolam stabilisasi dan constructed wetland

    yang sesuai ditunjukkan pada Gambar 15. Konfigurasi tersebut terdiri dari bak pengumpul,

    kolam anaerob, kolam fakultatif, kolam aerob, dan constructed wetland. Kolam stabilisasi

    dapat mengolah BOD tinggi dengan efisiensi yang cukup tinggi, lebih ekonomis, dan operasi

    serta pemeliharaannya mudah. Kolam stabilisasi dapat dibangun dengan material yang mudah

    didapat serta dalam pengoperasiannya sehari-hari tidak membutuhkan pekerja yang ahli

    (Mozaheb, 2010). Kolam stabilisasi selain mereduksi BOD juga dapat mereduksi bakteri

    faecal coliform (Mohammed , 2006).

    IPL seharusnya dilengkapi dengan bak pengumpul untuk meredam fluktuasi debit dan

    karakteristik lindi. Sedangkan pada IPL TPA Suwung tidak dilengkapi dengan bak

    pengumpul. Hal ini menyebabkan debit dan karakteristik lindi yang masuk ke dalam kolam

    anaerob berfluktuasi sehingga pengolahan pada kolam anaerob tidak berjalan maksimal dan

    efisiensi penyisihan pencemar rendah.

    Kolam stabilisasi biasanya diikuti dengan constructed wetland atau constructed

    wetland. Constructed wetland dapat berperan menyisihkan bahan pencemar melalui aktivitas

    bakteri, plant uptake, sedimentasi, dan penyaringan. Constructed wetland juga dapat

    menyisihkan logam berat Cr, Cu, Zn, dan Pb dengan efisiensi 30 80 % (Birch, 2004). Berdasarkan penelitian yang dilakukan oleh Nurulhuda (2010), constructed wetland dengan

    menggunakan tanaman Cyperus papyrus dapat menyisihkan COD, BOD, NTK, TSS, warna

    pada lindi berturut-turut sebesar 95,75%, 89,08%, 85,33%, 92,24%, 99%. Selain itu, juga

    terjadi penyisihan logam Fe, Cu, Zn sebesar 91,38%, 98,15% dan 97,71% (Risnawati, 2010).

    0

    10

    20

    30

    40

    Influen

    Anaerob

    Efluen

    Anaerob

    Efluen

    Fakultatif

    Efluen

    Aerob

    Efluen

    Constructed

    Wetland

    Fe (

    mg

    /L)

    Des-10 Mei-11

  • SW4 - 9

    Gambar 15 Konfigurasi Instalasi Pengolahan Lindi yang sesuai

    Kesesuaian Desain IPL dengan Kriteria Desain

    Setiap unit IPL yang ada yaitu kolam anaerob, kolam fakultatif, kolam aerob, dan

    constructed wetland diperiksa desainnya dan dibandingkan dengan kriteria desain.

    A. Kolam Anaerob Kondisi kolam anaerob IPL TPA Suwung adalah sebagai berikut :

    Panjang (p) = 25 m

    Lebar (l) = 20 m

    Kedalaman (h) = 2,5 m

    Panjang bafel = 16 m

    Lebar bafel = 0,2 m

    Jumlah bafel = 4

    Debit lindi yang masuk = 0,8 L/detik = 69,12 m3/hari

    Konsentrasi BOD in (So) = 3.667,67 mg/L

    Konsentrasi BOD out (Se) = 3.020 mg/L Hasil pengecekan dimensi kolam anaerob dengan kriteria desain ditunjukkan pada Tabel 6.

    Tabel 6 Perbandingan hasil perhitungan dengan kriteria desain unit kolam anaerob Parameter Satuan Kondisi

    Eksisting

    Kriteria

    Desain

    Ket* Sumber

    Kedalaman meter 2,5 2,5 5 V Qasim, 1985

    Waktu Detensi Min hari 17,6 2 5 V WHO, 1987

    Organic Loading Rate kg/m3.hari 0,21 0,3 V WHO, 1987 BOD Removal % 38,21 / 17,66 60 90 X Qasim, 1985 *V = memenuhi kriteria

    X = tidak memenuhi kriteria

    B. Kolam Fakultatif Kondisi kolam fakultatif IPL TPA Suwung adalah sebagai berikut :

    Panjang = 25 m

    Lebar = 15 m

    Jumlah kompartemen = 5

    Debit lindi yang masuk = 0,8 L/detik = 69,12 m3/hari

    Konsentrasi BOD in (So) = 3.020 mg/L

    Konsentrasi BOD out (Se) = 402 mg/L

    Dimensi tiap kompartemen kolam fakultatif ditunjukkan pada Tabel 7.

    Tabel 7 Dimensi kolam fakultatif (As Built Drawing TPA Suwung, 2009) Parameter Kompartemen

    I II III IV V

    Panjang, m 15 15 15 15 15

    Lebar, m 4,75 4,5 4,5 4,5 4,75

    Kedalaman, m 0,4 0,4 0,4 0,4 0,75

    Luas, m2 71,25 67,5 67,5 67,5 71,25

    Volume, m3 28,5 27 27 27 28,5

  • SW4 - 10

    Meskipun ada banyak metode untuk mendesain kolam fakultatif, Mara (1976)

    merekomendasikan untuk mendesain berdasarkan surface BOD loading ( s, kg/ha.hari). Hasil pengecekan dimensi kolam fakultatif dengan kriteria desain ditunjukkan pada Tabel 8.

    Tabel 8 Perbandingan hasil perhitungan dengan kriteria desain unit kolam fakultatif Parameter Satuan Kondisi

    Eksisting

    Kriteria Desain Ket* Sumber

    Kedalaman meter 0,4 0,75 1 2 X Qasim, 1985

    Waktu Detensi hari 2 7 50 X Benefield & Randall, 1980

    Organic Loading Rate kg/ha.hari 6.050,5 15 120 X Qasim, 1985

    BOD Removal % 5,30 / 86,69 70 95 X Benefield & Randall, 1980 *V = memenuhi kriteria X = tidak memenuhi kriteria

    C. Kolam Aerob Kondisi kolam aerob IPL TPA Suwung adalah sebagai berikut :

    Panjang (p) = 12,5 m

    Lebar (l) = 7,95 m

    Kedalaman (h) = 1,4 m

    Debit lindi yang masuk = 0,8 L/detik = 69,12 m3/hari

    Konsentrasi BOD in (So) = 402 mg/L

    Konsentrasi BOD out (Se) = 401,33 mg/L

    Penyisihan BOD pada kolam aerob atau kolam maturasi tidak terlalu tinggi tetapi penyisihan

    bakteri faecal tinggi (Mara, 2004). Perhitungan ini berdasarkan surface BOD loading. Hasil

    pengecekan dimensi kolam aerob dengan kriteria desain ditunjukkan pada Tabel 9.

    Tabel 9 Perbandingan hasil perhitungan dengan kriteria desain unit kolam aerob Parameter Satuan Kondisi

    Eksisting

    Kriteria Desain Ket* Sumber

    Kedalaman meter 1,4 0,3 1,0 X Qasim, 1985

    Waktu Detensi hari 2 5 20 X Qasim, 1985

    Organic Loading Rate kg/ha.hari 2.691,25 40 120 X Qasim, 1985

    BOD Removal % 12,02 / 0,17 40 80 X Qasim, 1985 *V = memenuhi kriteria

    X = tidak memenuhi kriteria

    D. Constructed Wetland Kondisi constructed wetland IPL TPA Suwung adalah sebagai berikut :

    Panjang (p) = 15,5 m

    Lebar (l) = 10 m

    Tinggi muka air = 1,5 m (dari dasar kolam)

    Tinggi media (h) = 1,3 m (dari dasar kolam), dengan rincian sebagai berikut : - Top soil dengan tanaman = 0,3 m

    - Batu marmer / batu kapur = 0,4 m

    - Tanah = 0,6 m

    Jenis tanaman = Rumput gajah (Penisetum purpureum) kondisi : mati Debit lindi yang masuk = 0,8 L/detik = 69,12 m3/hari

    Konsentrasi BOD in (So) = 401,33 mg/L

    Konsentrasi BOD out (Se) = 603,33 mg/L Hasil pengecekan dimensi constructed wetland dengan kriteria desain ditunjukkan pada

    Tabel 10.

  • SW4 - 11

    Tabel 10 Perbandingan hasil perhitungan dengan kriteria desain constructed wetland

    (subsurface flow constructed wetland) Parameter Satuan Kondisi

    Eksisting

    Kriteria Desain Ket* Sumber

    Waktu Detensi hari 1 3 4 (BOD) 6 10 (N)

    X Crites & Tchobanoglous, 1998

    Tinggi Muka Air m 1,5 0,3 0,6 X Crites & Tchobanoglous, 1998

    Tinggi Media m 1,3 0,5 0,8 X Crites & Tchobanoglous, 1998

    Beban BOD kg/ha.hari 1.789,67 < 112 X Crites & Tchobanoglous, 1998

    Beban Hidrolis m3/m2.hari 0,446 0,015 0,05 X Metcalf & Eddy, 2004

    Area Spesifik ha/(103m3/hari) 0,224 2,2 7,2 X Metcalf & Eddy, 2004

    BOD Removal % 9,35 / 0 65 88 X Crites & Tchobanoglous, 1998 *V = memenuhi kriteria

    X = tidak memenuhi kriteria

    Berdasarkan pengecekan desain IPL dengan kriteria desain, terlihat bahwa besarnya

    organic loading rate kolam pengolahan pada kolam fakultatif, kolam aerob, dan constructed

    wetland tidak memenuhi kriteria desain. Hal ini disebabkan oleh BOD yang masuk masih

    terlalu besar dan debit lindi yang masuk melebihi kapasitas desain IPL. Pada constructed

    wetland, BOD yang keluar lebih besar daripada BOD yang masuk. Hal ini disebabkan oleh

    constructed wetland sudah jenuh dan tanaman pun mati sehingga menambah nilai BOD pada

    outlet.

    SARAN PERBAIKAN

    Dari hasil evaluasi timbulan lindi, karakteristik lindi pada IPL TPA Suwung, dan juga

    dimensi setiap unit di IPL TPA Suwung diajukan beberapa kemungkinan saran perbaikan

    antara lain:

    Penambahan unit bak ekualisasi sebelum unit kolam anaerob. Bak ekualisasi ini berfungsi meredam variasi debit dan konsentrasi lindi yang masuk ke IPL.

    Penambahan by pass channel yang menghubungkan bak ekualisasi langsung menuju kolam fakultatif tanpa melalui kolam anaerob. By pass channel ini berfungsi mengalirkan

    lindi langsung ke kolam fakultatif jika konsentrasi BOD lindi yang masuk rendah.

    Redesain unit kolam fakultatif dan kolam aerob dengan menyesuaikan kedalaman kolam sesuai dengan kriteria desain dan memperluas kolam jika lahan yang ada tersedia atau

    redesain kolam fakultatif yang ada menjadi facultative aerated lagoon sehingga

    diharapkan dapat mengolah lindi pada BOD loading yang sesuai.

    Redesain unit constructed wetland dengan jenis constructed wetland yang sesuai dan pemilihan tanaman yang sesuai untuk mengolah lindi.

    PENUTUP

    Permasalahan yang ditemukan dari hasil evaluasi berdasarkan karakteristik efluen

    lindi adalah konsentrasi lindi berfluktuasi seperti ditunjukkan oleh perbedaan konsentrasi

    parameter lindi pada Desember 2010 dan Mei 2011. Pada Mei 2011, dimana konsentrasi

    parameter lindi tinggi, nilai TDS, TSS, BOD, COD, dan nitrit tidak memenuhi baku mutu.

    Efisiensi IPL TPA Suwung juga rendah. Hal ini disebabkan oleh desain IPL yang tidak sesuai

    dengan kriteria desain. Kedalaman kolam fakultatif dan kolam aerob tidak sesuai dengan

    kriteria desain. Selain itu, debit lindi yang masuk ke dalam IPL melebihi debit kapasitas

    desain sehingga waktu detensi lindi pada kolam pengolahan sangat singkat pada kolam

    fakultatif dan kolam aerob. Hal ini menyebabkan pengolahan di dalam kolam menjadi tidak

    optimal. Selain itu, constructed wetland pada IPL tidak berfungsi karena beban BOD yang

    terlalu tinggi.

  • SW4 - 12

    DAFTAR PUSTAKA

    Benefield & Randall. (1980). Biological Process Design for Wastewater Treatment. USA:

    Prentice-Hall, Inc.

    Birch, et al. (2004). Efficiency of a Constructed Wetland in Removing Contaminants from

    Stormwater. Journal of The Society of Wetland Scientists. Vol. 24. No. 2. pp 459 466.

    Crites & Tchobanoglous. (1998). Small and Decentralized Wastewater Management Systems.

    Singapore: McGraw-Hill, Inc.

    Damanhuri, Enri. (2008). Diktat Kuliah Landfill. Bandung: Teknik Lingkungan ITB.

    Kementerian Pekerjaan Umum. (2009). As Built Drawing TPA Suwung.

    Machibya, et al. (2006). Effect of Low Quality Effluent from Wastewater Stabilization Ponds

    to Receiving Bodies, Case of Kilombero Sugar Ponds and Ruaha river, Tanzania.

    International Journal of Environmental Research and Public Health. Vol. 3. No. 2.

    pp 209 216. Mara, Duncan. (2004). Domestic Wastewater Treatment in Developing Countries. UK:

    Cromwell Press.

    Metcalf & Eddy. (2004). Wastewater Engineering: Treatment and Reuse Fourth Edition.

    Singapore: McGraw-Hill, Inc.

    Mohammed. (2006). Design and Performance Evaluation of a Wastewater Treatment Unit.

    Journal of Departement of Agricultural Engineering, Federal University of

    Technology Minna, Niger State, Nigeria. Vol. 9. No. 3. pp. 193 198. Mozaheb, et al. (2010). Evaluation of Stabilization Ponds Performance for Municipal

    Wastewater Treatment in Yazd Iran. Middle-East Journal of Scientific Research. Vol. 6. No. 1. pp. 76 82.

    Naddafi, et al. (2009). Performance Evaluation of Wastewater Stabilization Ponds in Arak Iran. Iran Journal of Environmental Science and Engineering. Vol. 6. No. 1. pp. 41 46.

    Nurulhuda, Masayu. (2010). Penyisihan Senyawa Non Logam pada Lindi Menggunakan

    Constructed Wetland. Bandung: Tugas Akhir S1 Teknik Lingkungan ITB.

    Puslitbang Permukiman Kementerian Pekerjaan Umum. (2010). Hasil Pemeriksaan Lindi

    TPA Suwung Desember 2010.

    Qasim & Chiang. (1994). Sanitary Landfill Leachate. USA: Technomic Publishing Company,

    Inc.

    Qasim, Syed R. (1985). Wastewater Treatment Plant, Planning, Design, and Operational.

    New York: College Publishing.

    Risnawati, Imas. (2010). Penyisihan Logam pada Lindi Menggunakan Constructed Wetland.

    Bandung: Tugas Akhir S1 Teknik Lingkungan ITB.

    WHO. (1987). Wastewater Stabilization Ponds: Principles of Planning and Practice.

    Alexandria: WHO EMRO Technical Publication No. 10.


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