Technology Needs for the Water Sector Pradeep Mujumdar Indian - PowerPoint PPT Presentation

Technology Needs for the Water Sector Pradeep Mujumdar Indian Institute of Science Bangalore India 1

INTRODUCTION v 2

Introduction Water Stress = f (Quantity, Quality, Uncertainty)  Water sector in the country has been seriously impacted due to a combination of climate change, population growth, rapid urbanization, and industrial growth.  Signals of climate change convert into regional scale hydrologic change in terms of modifications in water availability, agricultural water demand, hydrologic extremes of floods and droughts, deterioration in water quality, salinity intrusion in coastal aquifers, groundwater recharge and other related phenomena.  Deployment of climate friendly technologies is essential across the water sector. 3

Mil illions at t Risk Source : Parry et al. (2001) 4

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WATER AUGMENTATION v 6

Water Augmentation Technologies to achieve water security, by augmenting available resources and increasing the availability by other feasible means:  Wastewater recycling (to improve quality of water)  Wastewater treatment, reuse and recycle: Household, community and city level.  Industrial wastewater treatment and recycling  Desalination  Use of renewable energy  Aquifer recharge and rejuvenation  New water source : substitutes of fresh water sources for human consumption as well as for domestic and industrial purposes. 7

Wastewater treatment, reuse and recycle • The treatment can be achieved in centralized locations, communities or at the end of the pipe simple filtration Technologies for wastewater treatment Sl. Technology Environmental Impact/Benefits Remarks No. Technology for Urban and Peri Urban areas: Expensive, less space requirement, good treated water quality 1 Membrane bio reactor MBR Same principle as Activated Sludge Process (ASP) or extended A few plants are available in India aeration Provide highest quality effluent Costly and high power requirement High O&M Cost 2 Sequential Batch Rector Alternative to ASP or Extended Aeration (EA) Many plants are coming up in Provide high quality effluent India Good nutrient removal 3 Submerged aerobic Fixed Film Alternative to ASP or EA for small scale systems Many plants are existing in India Provide good quality effluent 4 Moving Bed Biological reactor(MBBR, Alternative to ASP or EA for small scale systems Many plants are existing in India FAB, MMBR, Compact units) Provide good quality effluent 8

Technologies for wastewater treatment Sl. Technology Environmental Impact/Benefits Remarks No. Technology for Urban and Peri-Urban areas: Expensive, less space requirement 5 *Extended Aeration Systems (EA) Most common Technology; Very good quality effluent; High power Many plants are existing in India consumption 6 Activated Sludge process (ASP) Alternative to EA; Good quality effluent Many plants are existing in India Sludge treatment is needed 7 Onsite Aerobic Packages Alternative to Compact MBBR, FAB etc; Less area requirement Many plants are existing in India 8 Contact Aeration System for Individual Alternative to Compact MBBR, FAB etc for individual houses A few plants are available in India Houses (STBF series) Less area requirement; High quality effluent 9 Trickling Filter/Bio tower (TF, BT) Alternative to EA; Low power requirement Some plants are existing in India 10 Activated Sludge Package plants Alternative to EA for small quantity of wastewater A few plants are available in India 11 Rotating Biological Contactors Alternative to EA; Low power requirement Many plants are existing in India 12 Oxidation Ditch (OD-EA) Extended aeration system for small communities A few plants are available in India High quality effluent 9

Technologies for wastewater treatment Sl. Technology Environmental Impact/Benefits Remarks No. Technologies for Rural and Per-urban Areas, inexpensive and relatively less space requirement 13 Aerated Lagoon Up gradation of waste stabilization pond A few plants are available in India Needs further treatment for meeting the discharge standards 14 Constructed Wetlands and VORTEX Alternative to DEWATS; Good quality effluent A few plants are available in India 15 DEWATS/BORDA Less space requirement; Less capital investment; No energy Large number of installations are requirement done in India 16 DEWATS(ABR and CW) Less space requirement; Less capital investment; No energy Large number of installations are requirement done in India 17 Constructed soil filter, solid immobilized Promoted as competitive option for DEWATS; Good quality A few plants are available in India bio filter, Soil Biotechnology (SBR) effluent 18 Upflow Anaerobic Sludge Blanket Reactor Low power requirement; Energy generation; Low effluent quality A few plants are available in India (UASB) 19 Anaerobic Filters (AF) Suitable for high strength wastewater; Low power requirement A few plants are available in India Energy generation; Low effluent quality 10

Technologies for wastewater treatment Sl. Technology Environmental Impact/Benefits Remarks No. Rural Areas or areas where Cheaper Land is available, Low treated water quality, Natural systems 20 Waste Stabilization Ponds Most simple technology Large number of installations are Natural System made in India Low effluent quality 21 Onsite package: Anaerobic systems for Alternative to septic tank A few plants are available in India individual houses (SINTEX, PWTs-Am, Low effluent quality CCST, THST) 22 Karnal Technology Sewage irrigation for selected plants A few plants are available in India Risk due to pathogens 11

Industrial wastewater treatment and recycling • Water scarcity can adversely affect the industrial production • In India, sugar and distillery, tannery, textile, pharmaceutical etc. industries consume large quantities of water and generate highly polluted wastewater. • To abate the environmental pollution and to protect the dwindling water resources, these industries have to practice Zero Liquid Discharge (ZLD) concepts i.e. no liquid discharge will be happening from the systems. • The major challenges faced by the ZLD systems are the energy cost, operation and maintenance and the management of residual mixed salt generated from the treatment systems. ZLD Concept Source: https://www.saltworkstech.com/articles/what-is- 12 zero-liquid-discharge-why-is-it-important/

Desalination • Desalination refers to the process by which potable water is recovered from sea water/brackish water by removing dissolved solids using different forms of energy. • Different technologies are used for water desalination such as  Thermal processes  Membrane processes Source: https://www.jewishla.org/israeli-inventions-desalination- and-drought/ 13

Desalination Technologies Thermal Desalination LTTD (Low Temperature Thermal Desalination) Multi-Stage Flash (MSF) desalination Multi Effect Distillation (MED) process Source: Source: http://www.everestblowers.com/vacuum-systems-for- Source: http://www.separationprocesses.com/Distillation/DT_Chp0 low-temprature-thermal-desalination-lttd.html http://www.separationprocesses.com/Distillation/DT_Chp0 7b.htm 7a.htm 14

Desalination Technologies Membrane distillation (MD) Electrodialysis (ED) for Water Desalination. Journal of Chemistry, 2016. Investigation of O-Ring Vacuum Membrane Distillation Module Source: Alhathal Alanezi, A., et al. (2016). Performance 101-introduction-to-electrodialysis-reversal Source: https://www.slideshare.net/laxer_12/edr- Common Membrane Desalination Processes Reverse Osmosis (RO) membrane technology Source: http://www.water- treatment.com.cn/technologies/RO_Reverse- Osmosis/introduction.htm Forward Osmosis (FO) Capacitive deionization Source: http://www.htiwater.com /technology/forward_os Source: 15 mosis/index.html https://upload.wikimedia.org/wikipedia/commons/0/01/Cap acitive_deionization_-_Adsorption.pdf

Desalination Technologies Technologies Technology available – domestic/ global level Remarks Multi-Stage Flash MSF Domestic & Global level When steam is available is large quantities, fresh water can be easily generated. Multi Effect Distillation(MED) Domestic & Global level Lowest energy consumption among thermal systems when steam is available. Low Temperature Thermal Thermal pollution due to rejection of hot seawater by the coastal power plants Domestic Desalination (LTTD) can be mitigated. Ocean thermal gradient can be used in suitable locations. Mechanical / Thermal Vapour Global level Yet to become widely acceptable Compression High concentrated brine and chemical additives used for pre-treatment are may Reverse Osmosis Domestic & Global level affect marine life. However the cheapest method today. Forward Osmosis Global level Yet to reach large scales Ion Exchange Global level Commercially expensive Multi Effect Humidification (MEH) Global level Yet to become popular at large scales Bio-desalination Global level Laboratory level Electro Dialysis(ED) Global level Expensive ElectroDialysis reversal (EDR) Global level Expensive Membrane Distillation (MD) Global level Laboratory level Plimmer, a CDI based water purifier by Aquasphere, India is approved by Ministry of Drinking water and CDI (Capacitive Deionization) Sanitation for rural drinking water programs. Yet to be scaled up commercially The CDI unit of 4000 lit/day capacity is being used to 16 treat contaminated well water in Kadur, Karnataka.