This document discusses wastewater reuse and provides several examples. It defines wastewater reuse as using treated wastewater from one application for another. Common reasons for reuse include identifying new water sources due to increasing demand and meeting more stringent discharge standards. Types of reuse include urban, agricultural, recreational, environmental, and industrial uses. The document provides examples of wastewater reuse projects in Europe and discusses using microfiltration technology to treat wastewater for irrigation in Kuwait.

1. Reuse of Treated
wastewater
PULKIT SHUKLA
SIDDHARTH KATIYAR
ROBIN AJMERA
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2. What is Wastewater Reuse
The U.S. Environmental
Protection Agency (EPA)
defines wastewater reuse as,
“using wastewater or reclaimed
water from one application for
another application. A
common type of recycled
water is water that has been
reclaimed from municipal
wastewater (sewage).”
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3. Reasons for Wastewater Reuse
 The most common reasons for establishing a
wastewater reuse program is to identify new water
sources for increased water demand and to find
economical ways to meet increasingly more stringent
discharge standards
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4. Types of Reuse
• Urban reuse-the irrigation of public parks, school yards , highway medians,
and residential landscapes, as well as for fire protection and toilet flushing in
commercial and industrial buildings.
• Agricultural reuse-irrigation of non food crops, such as fodder and fiber ,
commercial nurseries, and pasture lands. High-quality reclaimed water is used
to irrigate food crops.
• Recreational impoundments-such as pond sand lakes.
• Environmental reuse-creating artificial wetlands, enhancing natural wetlands,
and sustaining stream flows.
• Industrial reuse-process or makeup water and cooling tower water.
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5. Technical Description
 One of the most critical steps in any
reuse program is to protect the public
health, especially that of workers and
consumers. To this end, it is most
important to neutralize or eliminate any
infectious agents or pathogenic
organisms that may be present in the
wastewater. For some reuse
applications, such as irrigation of non-
food crop plants, secondary treatment
may be acceptable. For other
applications, further disinfection, by
such methods as chlorination or
ozonation, may be necessary. Table 18
presents a range of typical survival times
for potential pathogens in water and
other media
Table 18
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6. Application of Treated Wastewater
 Agricultural Irrigation
 Crop irrigation
 Commercial nurseries
 Landscape Irrigation
 Parks
 School yards
 Highway medians
 Golf courses
 Cemeteries
 Residential
 Industrial Recycling and Reuse
 Cooling water
 Boiler feed
 Process water
 Heavy construction
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7.  Groundwater Recharge
 Groundwater replenishment
 Saltwater intrusion control
 Subsidence control
 Recreational / Environmental Uses
 Lakes & ponds
 Marsh enhancement
 Stream-flow augmentation
 Fisheries
 Non-Potable Urban Uses
 Fire protection
 Air conditioning
 Toilet flushing
 Potable Reuse
 Blending in water supply reservoirs
 Pipe-to-pipe water supply
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8. Historical Examples
 3000 BC – Crete (Minoan culture)
 Collection of rainwater and sand “filtration” for reuse
 1890 – Mexico
 Agricultural irrigation
 1912 – Europe & US
 Landscape irrigation
 1926 – US & Europe
 Industrial uses: cooling processes & boilers
 1960 – US; Europe; Africa; Australia
 Landscape Irrigation (including golf-courses)
 Groundwater Recharge
 Advanced WW reclamation for potable water supply augmentation
 1980 – US; Europe; Japan
 Water recycling for toilet flushing in urban areas
 Agricultural irrigation of food crops eaten uncooked
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9. Constituents to be checked in
Reclaimed Water
 Conventional (measured in mg/L; used in designing conventional WWTPs)
 TSS
 BOD; COD
 TOC
 Nitrogen (Ammonia; Nitrate; Nitrite)
 Phosphorus
 Microorganisms: Bacteria; Viruses ; Protozoan cysts & oocysts
 Non-conventional (to be removed or reduced by advanced treatment processes)
 Refractory organics
 VOC
 Surfactants
 Metals
 TDS
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10. Problems associated with Wastewater
Reuse
 Heavy Elements
 Public Health – nervous system disorders, mutagenesis, teratogenesis,
carcinogenesis
 Bioaccumulation (food chain on crops and animals)
 Surface water pollution
 Environmental Impact – acute and chronic toxicity for plant and animal life,
chronic degradation effect on soil
 Nutrients (N & P)
 Public Health – blue-baby syndrome (from NO3
-)
 infiltration into potable water supplies
 Environmental Health – Eutrophication, crop yield effects (+ive & -ive)
 Surface water pollution
 Irrigation practices
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11. Problems associated with Wastewater
Reuse
 Dissolved Solids (salinity)
 Environmental Health
 Induce problems for the crops’ yield selection and quantity
 Accumulation in soil
 Effect on soil permeability
 Clogging drip-irrigation systems
 Emerging Pollutants
 Public Health
 Acute and chronic health effects – effect on growth, reproduction problems
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12. Problems associated with Wastewater
Reuse
 Groundwater contamination
 Nitrate contamination on private drinking wells
 Antibiotics
 lower effectiveness of antibiotics if irrigation of fodder is involved
 Odor
 Public health of neighboring communities
 Aesthetic concern - Reduced land values
 Concerns with industrial processes
 Scaling
 Corrosion
 Biological growth & fouling
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13. Reclaimed wastewater can be safe for
agricultural irrigation
 Reduce the pathogen levels
 Avoid direct contact of crops with reclaimed wastewater
 Restrict the type of crops irrigated
 Different treatment for safe irrigation of different crops:
 For tree nurseries, pastures, industrial crops
 Secondary treatment & detention in surface reservoirs
 For fruits to be canned, vegetables for cooking and fruits with non-edible
peels
 Tertiary treatment (i.e. AS & Sand Filtration)
 For edible crops (uncooked)
 Tertiary treatment followed by soil aquifer treatment (or advanced)
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14. Guidelines and Regulations
TYPE OF REUSE TREATMENT RECLAIMED WATER
QUALITY
RECLAIMED WATER
MONITORING
SETBACK DISTANCES
Urban Reuse
Landscape irrigation,
vehicle washing, toilet
flushing, fire protection,
commercial air
conditioners, and other
uses with similar access
or exposure to the water.
Secondary
Filtration
Disinfection
pH = 6–9
<10 mg/L biochemical
oxygen demand (BOD)
< 2 turbidity units (NTU)5
No detectable faecal
coliform/100 mL4
1 mg/L chlorine (Cl2)
residual (min.)
pH – weekly
BOD – weekly
Turbidity – continuous
Coliform – daily
Cl2 residual –
continuous
50 ft (15 m) to
potable water
supply wells
Agricultural Reuse
For Non-Food Crops
Pasture for milking
animals; fodder, fiber and
seed crops.
Secondary
Disinfection
pH = 6–9
< 30 mg/L BOD
< 30 mg/L total
suspended solids (TSS)
< 200 faecal coliform/100
mL5
1 mg/L Cl2 residual
(min.)
pH – weekly
BOD – weekly
TSS – daily
Coliform – daily
Cl2 residual –
continuous
300 feet (90 m)
to potable water
supply wells
Indirect Potable Reuse
Groundwater recharge by
spreading into potable
aquifers.
Site Specific Secondary
and Disinfection. May
also need Filtration
and/or advanced waste
water treatment
Site specific
Meet drinking water
standards after
percolation through
vadose zone.
pH – daily
Turbidity – continuous
Coliform – daily
Cl2 residual – continuous
Drinking water standards
– quarterly
Other – depends on
constituent
100 ft (30 m) to
areas accessible
to the public (if
spray irrigation)
site specific
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15. Some Wastewater Reuse Advantages
and Disadvantages
• This technology reduces the demands o potable sources of freshwater.
• It may reduce the need for large wastewater treatment systems, if significant portions of the waste stream are
reused or recycled.
• The technology may diminish the volume of wastewater discharged, resulting in a beneficial impact on the
aquatic environment.
• Capital costs are low to medium for most systems and are recoverable in a very short time; this excludes
systems designed for direct reuse of sewage water.
• Operation and maintenance are relatively simple except in direct reuse systems where more extensive
technology and quality control are required.
• Provision of nutrient-rich wastewaters can increase agricultural production in water-poor areas.
• Pollution of rivers and groundwater may be reduced.
• Lawn maintenance and golf course irrigation is facilitated in resort areas.
• In most cases, the quality of the wastewater, as an irrigation water supply, is superior to that of well water.
 Advantages
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16. If implemented on a large scale, revenues to water supply and wastewater utilities may fall
as the demand for potable water for non-potable uses and the discharge of wastewaters is
reduced.
• Reuse of wastewater may be seasonal in nature, resulting in the overloading of treatment
and disposal facilities during the rainy season; if the wet season is of long duration and/or
high intensity, the seasonal discharge of raw wastewaters may occur.
• Health problems, such as water-borne diseases and skin irritations, may occur in people
coming into direct contact with reused wastewater.
• Gases, such as sulphuric acid, produced during the treatment process can result in chronic
health problems.
• In some cases, reuse of wastewater is not economically feasible because of the
requirement for an additional distribution system.
• Application of untreated wastewater as irrigation water or as injected recharge water may
result in ground
Disadvantages
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17. New Technologies and Approaches
Used In Wastewater Reuse
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 Membrane Filtration Systems
 Nanotechnology
 Microbial Fuel cells
 Natural Treatment Systems
 Urine Separating Toilets

18. Membrane Filtration Systems
 For wastewater
treatment
applications,
membranes are
currently being used
as a tertiary advanced
treatment for the
removal of dissolved
species; organic
compounds;
phosphorus; nitrogen
species; colloidal and
suspended solids; and
human pathogens,
including bacteria,
protozoan cysts, and
viruses.
 Membrane bioreactors—usually microfiltration (MF) or
ultrafiltration (UF) membranes immersed in aeration tanks
(vacuum system), or implemented in external pressure-
driven membrane units..
 Low-pressure membranes—usually MF or UF membranes,
either as a pressure system or an immersed system,
providing a higher degree of suspended . UF membranes
are effective for virus removal.
 High-pressure membranes—nanofiltration or reverse
osmosis pressure systems for treatment and production of
high-quality product water suitable for indirect potable
reuse and high-purity industrial process water. Also, recent
research has shown that microconstituents, such as
pharmaceuticals and personal care products, can be
removed by high-pressure membranes.
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19. Nanotechnology
 Further dramatic improvements are feasible in the near future (Shannon et
al., 2008). Nanotechnology concepts are being investigated for higher
performing membranes with fewer fouling characteristics, improved
hydraulic conductivity, and more selective rejection/transport
characteristics. Advances in RO technology include improved membranes
and configurations, more efficient pumping and energy-recovery systems,
and the development of process technology, such as membrane distillation
(Kim et al., 2008).
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20. Microbial Fuel Cells
 With microbial fuel cells, a potential breakthrough technology, electrical
energy could be extracted directly from organic matter present in the
waste stream by using electron transfer to capture the energy produced by
microorganisms for metabolic processes (Logan et al., 2006). First,
microorganisms are grown as a biofilm on an electrode; the electron donor
is separated from the electron acceptor by a proton exchange membrane,
which establishes an electrical current. Electrical energy is then generated
through the oxidation of organic matter (BOD5).
 Although this technology is still in the early stages of development and
significant advances in process efficiency and economics will be necessary,
it has the potential to produce electrical energy directly from organic
matter in the waste stream.
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21. Natural Treatment Systems
 Our fundamental understanding and characterization of processes in natural
treatment systems (NTSs) is also improving, enabling us to take advantage of
natural processes to improve water quality (Kadlec and Knight, 1996). In NTSs,
a variety of physical, chemical, and biological processes function
simultaneously to remove a broad range of contaminants.
For example, NTSs are increasingly being used to capture, retain, and treat
storm water, thereby converting this “nuisance” into a valuable source of water.
These natural systems have the advantage of being able to remove a wide
variety of contaminants, including nutrients, pathogens, and micro-
constituents (e.g., pharmaceuticals and endocrine-disrupting chemicals). Long
proven effective for treatment of potable water, NTSs are increasingly being
used for water reclamation.
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22. Urine Separating Toilets
 The development of urine-separating toilets and technologies for treating
urine to produce hygienic fertilizer products is a key to managing nutrients
with minimal requirements for outside resources, such as additional energy
(Larsen et al., 2001; Maurer et al., 2006). Urine-separating toilets have
already been developed and continue to be refined, and research on using
them for waste management is ongoing. Struvite precipitation and other
processes are already available for producing usable fertilizer products
from separated urine, and efforts are ongoing to improve the established
approaches.
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23. Case Studies-1
Wastewater Reuse in Europe
 In Europe the last two decades has witnessed growing water stress, both in
terms of water scarcity and quality deterioration, which has prompted
many municipalities to look for a more efficient use of water resources,
including a more widespread acceptance of water reuse practices.
 The study identified more than 200 water reuse projects as well as many
others in an advanced planning phase.
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24. Identifable Water reuse projects in Europe,including their size and intended use
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25. Conclusion
 Almost all medium- and large-scale schemes have been designed as add-
on technology to conventional secondary treatment processes.
 Despite the fact that water reuse is already becoming an essential and
reliable water supply option for many municipalities, there is still significant
potential for an increased utilisation of reclaimed wastewater.
 The water sector in Europe is in a transitional phase with unique
opportunities for water reuse to be implemented on a larger scale as a
sustainable practice within a framework of integrated water management.
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26. Case Study-2
Waste water quality and reuse in irrigation in Kuwait
using microfiltration technology in treatment
 Micro filtration (MF) unit has been tested in Kuwait Institute for Scientific
Research to treat the secondary wastewater effeulant from Riqqa
wastewater treatment plant.
 There was a consistent reduction in biological oxygen demand (BOD),
Chemical oxygen demand (COD), Total bacterial count (TBC) and total
suspended solid (TSS).
 The comparison is based on calculation sodium absorption ratio (SAR),
residual sodium carbonate (RSC), adjusted SAR, sodium hazards (SSP), and
measured parameters such as the electrical conductivity (EC), chloride,
calcium and potassium concentration, total suspended solids, trace metal
analysis and other parameters of health significance.
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27. Conclusion
 Mf filtrate water will not cause any clogging problem related to its EC, SAR,
and ESP.
 Only chloride potential might causes a moderate potential problem
 The MF product water satisfied all the microbiological and organic matter
restrictions and standards
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28. Case Study-3
The risks associated with wastewater reuse and
xenobiotics in the agroecological environment
 The technological progress in respect to analytical chromatographic
methods has enabled the identification and quantitation of a number of
organic xenobiotic compounds in treated wastewater.
 It is also widely accepted that the currently applied treatment processes for
urban wastewater abatement fail to completely remove such contaminants
and this lead to their subsequent release in the terrestrial and aquatic
environment through disposal and reuse applications.
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29. Conclusion
 Since the traditional wastewater treatment methods are not capable of
fully removing recalcitrant xenobiotic compounds, advanced technologies
must be applied such as Advanced Oxidation Processes (AOPs) and
membrane-separation technologies, which are effective in simultaneously
removing, both pathogens and xenobiotics, and perhaps their combined
application may constitute today, the best option for wastewater treatment
and reuse schemes.
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30. Case Study-4
Ultrafiltration for the reuse of spent filter backwash water
from drinking water treatment
 During most water treatment processes, spent filter backwash water
(SFBW) is generated.Innovations in membrane technology, especially in
micro- and ultrafiltration processes, offer a suitable treatment for SFBW in
order to guarantee a water quality necessary for reuse.
 Experiments were performed with SFBW from a full-scale water treatment
plant. The plant was operated with high fluxes of more than 40 L/(m2·h)
using clarified and non-clarified SFBW. Best membrane performance was
obtained using non-clarified SFBW.
 As a result, no space- and time consuming sedimentation processes are
necessary.Results confirmed that the filtrate can be used as an additional
and safe water source. When a continuous maintenance disinfection was
provided, filtrate was free of microbial contamination and could be reused
without any safety concerns.
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31. Listing of References
1. U.S. Environmental Protection Agency, Process Design Manual: Guidelines/or
Water Reuse.Cincinnati, Ohio, 1992 (Report No. EPA-625/R-92-004).
2. US Environment Protection Agency ,1992. Guidelines for Water Reuse
3. http://cdmsmith.com/en/Insights/Viewpoints/Membrane-Technology-Advances-
Wastewater-Treatment-and-Water-Reuse.aspx
4. D Bixtio, C. Thoeye, J. De Koning, D Joksimovic, D. Savic, T Wintgens, T. Melin
:Wastewater Reuse in Europe;Desalination 187(2006) 89-101
5. M. Al-Shammiri*, A. Al-Saffar, S. Bohamad, M. Ahmed; Waste water quality and
reuse in irrigation in Kuwait using microfiltration technology in treatment;
Desalination 185 (2005) 213–225
6. D. Fatta-Kassinosa, , , , I.K. Kalavrouziotisb, P.H. Koukoulakisc, M.I. Vasqueza The risks
associated with wastewater reuse and xenobiotics in the agroecological
environment Volume 409, Issue 19, 1 September 2011, Pages 3555–3563
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32. 7. Florian G. Reissmanna*, Wolfgang Uhlb; Ultrafiltration for the reuse of spent
filter backwash water from drinking water treatment;Desalination 198 (2006)
225–235
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33. TITLE SLIDE
 Reuse of Treated wastewater
 What is Wastewater Reuse
 Reasons for Wastewater Reuse
 Types of Reuse
 Technical Description
 Application of Treated Wastewater
 Historical Examples
 Constituents to be checked in Reclaimed Water
 Problems associated with Wastewater Reuse
 Reclaimed wastewater can be safe for agricultural irrigation
 Guidelines and Regulations
Page 33 of 34

34.  Some Wastewater Reuse Advantages and Disadvantages
 New Technologies and Approaches Used In Wastewater Reuse
 Membrane Filtration Systems
 Nanotechnology
 Microbial Fuel Cells
 Natural Treatment Systems
 Urine Separating Toilets
 Case Studies-1 Wastewater Reuse in Europe
 Case Study-2 Waste water quality and reuse in irrigation ...
 Case Study-3 The risks associated with wastewater reuse a...
 Listing of References
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