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- 1. Reuse of Treated wastewater PULKITSHUKLA SIDDHARTH KATIYAR ROBIN AJMERA Page 1 of 34
- 2. What is WastewaterReuse 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).” Page 2 of 34
- 3. Reasons for WastewaterReuse 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 Page 3 of 34
- 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. Page 4 of 34
- 5. Technical Description Oneof 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 Page 5 of 34
- 6. Application of TreatedWastewater 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 Page 6 of 34
- 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 Page 7 of 34
- 8. Historical Examples 3000BC – 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 Page 8 of 34
- 9. Constituents to bechecked 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 Page 9 of 34
- 10. Problems associated withWastewater 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 Page 10 of 34
- 11. Problems associated withWastewater 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 Page 11 of 34
- 12. Problems associated withWastewater 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 Page 12 of 34
- 13. Reclaimed wastewater canbe 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) Page 13 of 34
- 14. Guidelines and Regulations TYPEOF 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 PAGE 14 OF34
- 15. Some Wastewater ReuseAdvantages 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 Page 15 of 34
- 16. If implemented ona 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 Page 16 of 34
- 17. New Technologies andApproaches Used In Wastewater Reuse Page 17 of 34 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. Page18 of 34
- 19. Nanotechnology Further dramaticimprovements 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). Page 19 of 34
- 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. Page 20 of 34
- 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. Page 21 of 34
- 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. Page 22 of 34
- 23. Case Studies-1 Wastewater Reusein 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. Page 23 of 34
- 24. Identifable Water reuseprojects in Europe,including their size and intended use Page 24 of 34
- 25. Conclusion Almost allmedium- 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. Page 25 of 34
- 26. Case Study-2 Waste waterquality 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. Page 26 of 34
- 27. Conclusion Mf filtratewater 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 Page 27 of 34
- 28. Case Study-3 The risksassociated 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. Page 28 of 34
- 29. Conclusion Since thetraditional 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. Page 29 of 34
- 30. Case Study-4 Ultrafiltration forthe 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. Page 30 of 34
- 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 Page 31 of 34
- 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 Page 32 of 34
- 33. TITLE SLIDE Reuseof 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 WastewaterReuse 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 Page 34 of 34