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Introduction: Benefits and Domains of Wastewater Reuse Success Stories in Mediterranean Region:
Spain: Vitoria and Tenerife Plants Greece: Chalkis Island Plant Italy: Catania Projects Palestine: Dan Region Project Cyprus: Larnaca Plant Other Examples
Success Stories all over the World: Australia: Bolivar Project USA: Monterey, California
Introduction
Best Practices and Success Stories in Wastewater Treatment Systems are:
Systems employing an effective treatment technology leading to a good quality effluent
Systems with high contribution into the overall increase of wastewater reuse in the relevant country
Systems achieving sustainable wastewater treatment and reuse practices
Benefits of Wastewater Reuse
Potential benefits of wastewater reuse are most obvious for the arid areas but the general increasing pressures on water resources all over the world is also making wastewater reuse attractive in other areas.
All these benefits contribute to the
ultimate objective of
sustainable use of water
resources
The Mediterranean Region: The Need for Wastewater Reuse It is characterised by the low level and
irregularity of water resources, through time (summer drought, interannual droughts) and space (dry in the South).
It includes 60% of the world population with renewable natural resources of less than 1,000 m3 of water/inhabitant/year.
The strong growth in urbanisation, tourism, irrigation and population can only increase tensions on water demand.
Objectives of the Reuse Scheme A Tertiary Treatment Station was added in
1995 to the Municipal Wastewater Treatment Plant to obtain a better effluent capable of:
Increasing water supply to Vitoria and Bilbao cities Replacing ecological flows to the Zadorra dams
when they are deficient Irrigating 10,000 ha of agricultural land Protecting the trout fish of the Zadorra River
The Treatment Technology
Secondary treatment (screening, sedimentation, nitrification-denitrification) + tertiary treatment (coagulation-flocculation, sand filters, chlorine disinfection)
Effluent Quality
Parameter Min MaxpH 6.9 7.6
Conductivity 700 1000
Turbidity (NTU) 0.3 1.7
S.S (mg/l) 1 2.5
BOD5 (mg/l O2) 1 8
COD (mg/l O2) 3 20
N-NH3 (mg/l N) 23 30
N-NO3 (mg/l N) 0.1 0.2
PO4 (mg/l PO4) 0.3 1.5
TC (ufc/100 ml) 0 0
FC (ufc/100 ml) 0 0
Dose NaClO (mg/l Cl2) 5 8
SDI (Silt Density Index) 25 to 0.4 60 to 1
Metals (mg/l)
Level
Fe <0.21
Al <0.32
Zn <0.25
Ni <0.07
Cr 0.007
Co 0.009
Cd 0.002
Cu 0.008
Pb 0.0014
Mo 0.0026
Mn 0.076
Effluent Reuse
The Plant will generate 20,000,000 m3/year of treated effluent: 8,000,000 m3/year will be used for irrigation without
cultivations restriction 12,000,000 m3/year will be added to the Zadorra River
ecological flow
The effluent is suitable for drinking water supply!! (illegal at present)
Cost: 0.06 €/m3
Plant General Characteristics Constructed between
1995 and 1997 to alleviate the water shortage of the island of Tenerife
Designed for a flow of 90,000 m3/d
Effluent is used to irrigate a crop area located 70 km away from the Plant
Reservoir
Plant
The Wastewater Reuse System
Activated Sludge
15.000 m3
6.7 km
61 km; 0.6 km diameter Gravity Pipe completely filled 50,000 m³; 10 m
deep
250,000 m³; 15 m deep
457,000 m³; 20 m deep
Effluent Quality (Influent to San Isidro Reservoir)
Parameter Winter Spring-Summer
Winter-Spring
pH 7.74 7.98 7.91
EC (µS/cm) 1,288 1,659 1,585
S.S (mg/l) 8 5 11
COD (mg/l) 48 59 52
N-NH3 (mg/l) 26.3 42.3 23.5
N-NO2 (mg/l) 0.04 0.02 0.03
N-NO3 (mg/l) 0.06 0.46 0.31
PO43- (mg/l) 27 41 30
SO4 2- (mg/l) - 119 91
S2- (mg/l) 2.71 4 2.1
FC (log) 4.1 4.2 4.1
Problem and Solution
Anaerobic conditions build-up in the long pipe that transports the effluent leading to sulphide generation
Fresh water over-saturated with DO started to be injected at 10 km from the pipe inlet nitrification-denitrification process anoxic conditions inhibition of sulphide generation reduction in NH3-N less chlorine requirement for disinfection
Effluent Reuse
Reuse of 7,000,000 m3/year of treated effluent
Irrigation of 775 ha of banana mainly, plus potatoes and tomatoes
Acceptable quality, and studies are ongoing for its improvement using micro and ultra filtration
Cost: 0.45 €/m3
Plant General Characteristics Constructed in
1994
Reclamation of wastewater started in 1998
Daily flow of 9,000 m3/day
Disinfection Process
In 1998, ultraviolet disinfection using two types of UV systems (closed and open type) and chlorination was introduced
The first UV bank produced 55 mWs/cm2. After test, it was decided to increase the total dose of the UV lamps to 120 mWs/cm2
Effluent QualityParameter Average Value
Temperature ºC 21.2
pH 7.14
Redox mV 60
Suspended Solids (SS) mg/l 12
COD mg/l 54
BOD mg/l 9
N-NH4+ mg/l 6.6
N-NO3- mg/l 5.5
N-NO2- mg/l 0.3
Total Phosphorous mg/l 4.0
UV Transmission %T 55.3
Effluent Reuse
Reuse of 4000 m3/day of treated effluent for landscape irrigation (280 ha with 100,000 trees and bushes) and industrial use
1994 2000
Italy: Catania Italy: Catania Caltagirone and Caltagirone and
Grammichelle ProjectsGrammichelle Projects
Projects Characteristics
Grammichelle
Developed in 2001 Flow: 1,500 m3/d Activated Sludge + Chlorine
Contact Tank + Tank Storage
Quality: BOD5 < 10 mg/l; COD < 30 mg/l
Reused for irrigating orange, olive trees, crops for caning industry, and vegetables to be eaten cooked
Cost: 0.11 €/m3
Caltagirone
Developed in 2001 Flow: 5,200 m3/d Activated Sludge + Sand
Filtration + Reservoir Storage
Quality: BOD5 < 10 mg/l; COD < 30 mg/l
Reused for irrigating orange, olive trees, crops for caning industry, and vegetables to be eaten cooked
Cost: 0.11 €/m3
Plant and Effluent Characteristics Constructed in
1991-1994 Flow of
120,000,000 m3/yr
Parameter Value
BOD5 mg/l <0.5
COD mg/l 7
FC/100 ml 1
TC/100 ml 1
TSS mg/l 1
TN mg/l 0.4
TP mg/l 0.08
Treatment Technology
Effluent of biological treatment including nutrient removal is spread on sand basins and thus recharged into the groundwater aquifer for additional polishing and long-term storage
Effluent Reuse
In 1993, 75 out of 87 Mm3 of treated wastewater was recharged and about 100 Mm3 (together with groundwater) was used for agricultural irrigation in Negev of an area of ~ 16,000 ha of field-crops (cotton, cereals, sunflower, etc.), fruit plantations, vegetables, and flowers aimed for export
Cost: 0,45 US$/m3
Plant General Characteristics Located behind the International Airport of
Cyprus
Operation started in 1995, and reuse for irrigation purposes in 2000
Design capacity: 8,500 m3/d; In summer: 5,500 m3/d and in winter: 4,500 m3/d
Effluent Quality
Parameter Value Removal Efficienc
ypH 7.5 -
Total EC/100 ml 5 -
Intes. EC/100 ml 0 -
S.S (mg/l) 1.7 99.46
BOD5 (mg/l) 2.6 99.37
COD (mg/l) 56 93.1
N-NH3 (mg/l) 2.4 96.76
N-NO3 (mg/l) 6.9 -
Total N 8.5 90.22
Conductivity mS/cm
3.4 -
Parameter
Value Removal Efficiency
Cl 555 2.97
B 0.8 -
P 0.6 92.04
Cd <0.01 -
Cu 0.01 -
Ni 0.06 -
Pb 1.87 -
Zn 0.35 -
Cr III <0.01 -
Residual Cl 0.2 -
Effluent Reuse
Irrigation of 150 ha of corn and alfalfa at Dromolaxia Village; these started to grow noticeably fast
Irrigation, during the summer season, of gardens, parks and fields owned by hotels, the International Airport and Larnaca Municipality
Cost: 0.5 €/m3
Country Name of the Plant
Capacity m3/day
Treatment Technology
Reuse Application
Cost
Jordan Al Samra 150,000 3 trains of ponds: 2 anaerobic, 4 facultative, 4 maturation
Irrigation of 500 ha of olive trees, forest area, fodder crops and non-restricted vegetables for experiments
NA
Morocco City of Drargua
600 Primary treatment (aerobic basins), secondary treatment (sand filters), tertiary treatment
Irrigation of 6 ha of alfalfa, tomatoes, zucchini, corn and grass
NA
Tunisia Cebela 100,000 NA Irrigation of 3,200 ha of cereals (wheat, barley, triticale and hay), golf courses, green belts, hotel gardens, orchards
0.003 $/m3
Turkey Gaziantep 200,000 Primary treatment, secondary treatment (Activated Sludge)
Irrigation of 8,000 ha of edible crops, vegetables and nearby fields
NA
Plant Characteristics Developed in 1999-2002
Flow: 150,000 m3/day
Treats urban and industrial wastewater
Serves Adelaide and Gawler-Elizabeth-Salisbury regions in South Australia
Tanks and Lagoons Tertiary Treatment Plant
Treatment Technology
Screening and Grit Removal
Pre-Aeration Tanks
Primary Sedimentation
Activated Sludge
Settlement Tanks
Oxidation Ponds
Dissolved Air Flotation Filtration
Chlorine Disinfection
Aquifer Storage & Recovery
+Sludge Stabilization Ponds
Pre-Aeration Tanks
Effluent QualityBolivar WWTP Effluent
Parameter Value
pH 6.9
Temperature °C 18.3
EC/100 ml -
DO (mg/l) 6
TSS (mg/l) -
TN (mg/l) 7.8
TP (mg/l) 2.3
TOC (mg/l) 20.1
Conductivity (µS/cm) 1,975
ASR System Effluent
Parameter Value
pH 7.06
Temperature °C 22.7
EC/100 ml 0
DO (mg/l) 0
TSS (mg/l) 1
TN (mg/l) 15.6
TP (mg/l) 0.24
TOC (mg/l) 10.6
Conductivity (µS/cm) 2,470
Achievement of quality required for non-restricted irrigation!
Effluent Reuse
Irrigation of 3,500 ha of vegetables across the Northern Adelaide Plains through Virginia Pipeline Scheme (see Green area on photo)
Watering of plant lawns and gardens
Cleaning and flushing of equipment inside the plant
Cost: Construction 53 Million AU$ and Operation 0.12 AU$/m3
Wastewater Reuse in California Wastewater reuse has been practiced
since 1890 Historically, agricultural reuse has
been practiced Over the last decade landscape
irrigation in urban areas and groundwater recharge have been increasingly practiced
Major Wastewater Reclamation Systems
Wastewater Treatment Plant Name Reclaimed Water Delivery m3/d
San Jose Creek 67,101
City of Bakersfield 56,875
Whittier Narrows 53,648
City of Modesto 48,630
Fresno-Clovis Metropolitan Area Facilities 46,284
Pamona 32,435
Laguna 31,560
Michelson 29,536
City of Bakersfield 26,447
City of Tulare 21,114
Lancaster 18,539
South Tahoe 17,184
Total 449,355
Types of Crops Irrigated
Food Crops Non-Food Crops
Apples Grapes Alfalfa
Asparagus Lettuce Christmas trees
Avocados Maize Clover
Barley Peaches Cotton
Beans Peppers Eucalyptus trees
Broccoli Pistachios Flower seeds
Cabbage Plums Hay
Cauliflower Squash Maize
Celery Sugarbeets Sod
Citrus Wheat Vegetable seeds
Other trees
Monterey Wastewater Reclamation Study for Agriculture (1980) A pilot tertiary reclamation
plant (employing two parallel tertiary treatment units) was added to Castroville 1500 m3/day-WWTP
Dechlorination of final effluent was practiced till 1983 and was stopped afterwards
The objective is to study full-scale farm practices using reclaimed municipal wastewater
Pilot Study Details
Two 5-ha experimental plots were used in the lower Salinas Valley: On one plot, artichokes were grown On the other, a succession of broccoli,
cauliflower, lettuce and celery
The plots were intended to provide data on crop response to two variables: Irrigation water type (T22 effluent, FE effluent,
well water) Fertilization rate (33%, 66%, 100%)
Pilot Study Results: Treated Effluent Quality Salinity in the reclaimed effluents was a
bit high, but not so high as to cause soil permeability problems
Coliform levels of reclaimed effluents met the most stringent of the California Wastewater Reclamation Criteria
The reclaimed effluents had levels of heavy metals an order of magnitude lower than the metal input from impurities in commercial fertilizers
Pilot Study Results: Plant Tissues
Analysis of plant edible tissues showed that there was no difference, between plants irrigated with reclaimed effluents and plants irrigated with well water, in the level of:Heavy metalsTotal and Faecal Coliforms
Pilot Study Results: Crop Yield Celery and broccoli crops gave higher yield with the
reclaimed effluent irrigation Yields of lettuce and celery showed interaction of
water type and fertilization: reclaimed wastewater irrigation improved yields in unfertilized plots but had little effect on plots receiving fertilizers
Artichoke yields were similar with all three irrigation water types
Reductions of up to 33% of fertilizer application were possible when reclaimed wastewater is used
Other Pilot Study Results
No leaf damage due to residual chlorine (that’s why dechlorination practice was stopped in 1983)
No difference in plant appearance for all 3 types of irrigation water
Cold storage tests showed no unexpected deterioration of produce
The shelf life of produce irrigated with reclaimed wastewater was sometimes superior to that irrigated with well water
No adverse impacts in terms of soil or groundwater quality degradation
No health problems with project personnel
Monterey Regional Wastewater Treatment and Recycling Plant In 1992-1997, Monterey
Regional Water Pollution Agency and Monterey County Water Resources Agency developed two projects:
A Water Recycling Facility at the Regional Treatment Plant
A distribution system including 45 miles of pipeline and 22 supplemental wells
The Plant employs the Title 22 (T22) treatment technology
Effluent Reuse
The project produced 8,000 m3/day of reclaimed wastewater distributed to farmlands in the Northern Salinas Valley for food crops irrigation
Technicians perform frequent water quality tests to monitor the system
During rainy season, excess water is safely discharged 2 miles away in the Monterey Bay