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transcript
3/13/2008
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ENVIRONMENTAL FATE AND BIOACCUMULATION
Processes in the environment : fate of chemicals
Sorption to sediment particles
Anaerobic degradation
Resuspension sedimentation
Uptake (accumulation)
IKAN
Sorption to suspended particles and dissolved organic carbonAerobic degradation
Xfree Xbound
Air
Water
Sediment
BURUNG
Transport between media : example sediment-water
Assumption of equilibrium :
Equilibrium partition :
Medium 1e. g. water Cw
Medium 2 e. g. sediment Cs
Kp : partition coefisient sediment-water/ sorption coefficient
Kp = Cs/Cw
sediment
water
air
Partitioning between sediment (or soil) and water
Assumption of Equilibrium partition :
Medium 1e. g. water Cw
Medium 2 e. g. sediment Cs
Kp : partition coefficient sediment-waterKp = Cw/Cs
Koc : organic carbon normalized partition coefficientKoc = Kp/foc
Cs = concentration in soil or sedimentCw = concentration in waterfoc = fraction organic carbon in sediment or soil
Partitioning between sediment (or soil) and water
Sediment particle Kp : partition coefficient sediment-waterKp = Cs/Cw
Koc : organic carbon normalized partition coefficientKoc = Kp/foc
Koc is a property independent of the type of sediment or soil
Organic carbonfoc = 0,01
foc = 0,05
Kp
foc
Koc
Soil sorption coefficient of a new chemicals
Chemical log Kow log Koc
Benzene 2,19 1,96Toluene 2,79 2.39Naphthalene 3,30 3,11Anthracene 4,45 4,27PCB245245 7,16 5,65ppDDT 6,91 5,31ppDDE 6,96 4,82
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Hydrophobicity as important parameter : the octanol-water partition coefficient : Kow
Hydrophobicity is tendency of a chemical to “escape” water, and it depend on :
Hydrophobic phases : lipid phase (biota) organic carbon (sediment)
- Size- Presence of polar groups H2O
Chemical x
KowMethanol 0,17Acetanol 0,58Benzene 134DDT 1,0 107
Soil sorption in relation to hydrophobicity
log Koc versus log Kow
0
2
4
6
8
0 2 4 6 8
log Kow
log
Koc
Bioaccumulation
Topics :
models for accumulation
different sources of uptake
influence of properties on accumulation, including biotransformation
Uptake and elimination processes
BiotransformationUptake Fish
Cf
Reproduction kr
Elimination
ke
km
Growth γ
From van Leeuwen and Henmens, 1995 : Risk Assessment of Chemicals Chapter 3 (van den Berg et al.)
Three uptake routes : water, food and sediment
Water (Cw)
Food (Cfood)
Sediment (Cs)
kw
kf
ks
Organism (Co)ke Surrounding
medium
From van Leeuwen and Henmens, 1995 : Risk Assessment of Chemicals Chapter 3 (van den Berg et al.)
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Partitioning between sediment (or soil) and water : bioavailability
Assumption of Equilibrium partition :
Medium 1e. g. water Cw
Medium 2 e. g. sediment Cs
Kp : partition coefficient sediment-waterKp = Cs/Cw
Koc : organic carbon normalized partition coefficientKoc = Kp/foc
Cs = concentration in soil or sedimentCw = concentration in waterfoc = fraction organic carbon in sediment or soil
Uptake for water, food or soil
Bioconcentration BCF Co/Cw uptake from waterfactor
Bioaccumulation BAF Co/Cw uptake from water andfactor food, or sediment
Biomagnification BMF Co/Cf uptake from foodfactor
Biota to sediment BSAF Co/Cs uptake from water andaccumulation factor food, or sediment
Co = consentration in organismCf = consentration in foodCs = consentration in sediment
Influence of properties on accumulation
Accumulation depends on :• Hydrophobicity• Size• Ionization• Stability of the parent compound (biotransformation)
BiotransformationUptake Fish
Cf
Reproduction kr
Elimination
ke
km
Growth γ
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Ecotoxicity evaluation
Bird MammalAmphibian
orReptile
IndirectToxicity
SoilInvertebrateCommunity
PlantCommunity
BenthicCommunity
FishCommunity
DirectToxicity
Contaminated Environmental Medium
Food chain
Ecotoxicity evaluationMammalian Pathway
Bird MammalAmphibian
orReptile
IndirectToxicity
SoilInvertebrateCommunity
PlantCommunity
BenthicCommunity
FishCommunity
DirectToxicity
Contaminated Environmental Medium
Food chain
Ecotoxicity evaluationFish eating Birds
Bird MammalAmphibian
orReptile
IndirectToxicity
SoilInvertebrateCommunity
PlantCommunity
BenthicCommunity
FishCommunity
DirectToxicity
Contaminated Environmental Medium
Food chain
Environmental Fate of Nitrobenzene:Physico-chemical properties Environmental Release:
Depending on its purity: pale yellow-brown oily liquid at room temperature; odor: bitter almonds and shoe polish (vapor pressure 0.27 mmHg @ 25°C)Released into environment from: primarily industrial uses (production of aniline, rubber chemicals, pesticides, dyes, pharmaceuticals); formed in the atmosphere by nitration of benzene
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In air levels: from industrial areas 0.09 ppb up to 3.5 – 5.7 ppb. Atmospheric samples were higher during summer, and lower during heavy rain or snow. Air sample over landfill max. 14.48 ppbIn surface water: only 0.4% of 836 stations and 1.8% of 1245 reporting industrial wastewatersIn soil: 8 ppm along Buffalo River in New York, but not in sediment samplesIn 1992 USA: total released 917 thousand pounds- to atmosphere: 52 thousand pounds (5.6%)- to surface water:442 thousand pounds To underground injection sites: 865 thousand pounds (94.32%)No nitrobenzene was released to land
Transport
Nitrobenzene will volatile slowly from soil to surface water and is subjected to biodegradationAdsorption and bioconcentration are not thought to be significant fate processes in waterNitrobenzene may leach through soil and is considered to have intermediate mobility
Transformation/Persistence - AIR
undergoes photolysis photoproducts: ortho- and para- nitophenols and nitrosobenzenelab test: 35% nitrobenzene photochemically degraded in 5 hours by irradiation of xenon lampchemical reacts slowly with hydroxil radicals and ozonehalf-life for reaction of nitrobenzene and hydroxyl radicals and ozone in moderately polluted air: 90 days and 2 yearsremoval by wet deposition is not significant
Transformation/Persistence - SOIL
Subjected to biodegradation in soilHowever results from screening test was conflicting: with activate sludge inoculum from 98% in 5 days to no degradation in 10 days
Transformation/Persistence - WATER
Subjected to biodegradation and photodegradationSmall amount also adsorb to sediment or volatile from the surfaceHalf-life in model waste stabilization ponds: 3.8 days; 89.5% of the added chemical was degraded; 4.9% volatilized, 2.3% adsorbed to sediment; 2.4% lost in effluent; and 1% remainedHalf-life in aquatic environments estimated: 0.3 days
Transformation/Persistence - BIOTA
Bioconcentration factors in two species of fish L.idus and P. promelas estimated at 15 and less than 10, and in P. reticulata: 3 Nitrobenzene is not expected to accumulate significantly in aquatic organisms, however, it has been shown to be taken and may bioconcentrate in terrestrial plants
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SOAL EKOKINETIKA
(Dikumpulkan minggu depan di TU TL, ditulis tangan pada HVS A4)
Pada area pertanian terdapat danau yang selama 20 tahun menerima limbah kimia. Analisis terhadap sedimen menunjukkan kandungan lindan 0,38 mg/kg. Terdapat hewan common tern dan otter yang makan ikan dari danau tersebut. Ada juga sapi, diambil dagingnya, yang minum dari danau.
Pertanyaan:
a. Berapa prediksi konsentrasi lindan di air danau?b. Berapa prediksi konsentrasi lindan di ikan?c. Berapa nilai BCF lindan terhadap ikan?d. Apakah dengan konsentrasi yang ditemukan akan
menyebabkan keracunan lindan pada Common tern dan otter?
e. Bila Max. Permissible Concentration (MPC) lindan di air pada Common tern 0,015 μg/L dan pada otter: 0,21 μg/L, berapa konsentrasi lindan yang boleh/harus ada di sedimen sehingga tidak membahayakan Common tern & otter.
f. Apa yang Saudara rekomendasikan dalam pengelolaan lingkungan untuk permasalahan ini? Uraikan!
Data: log Kow = 3,78, kw fish= 175 L/kg/d; log Kd= 2,4, BCFwet weight untuk lindan= 302 L/kg