Wastewater Treatment PDF

WASTEWATER TREATMENT PRESENTATION BY SHRIPAD NIMBHORKAR NIMBHORKAR STUDY NOTES 1  WASTEWATER TREATMENT What is wastewater ? Water which is used in process and comes out for disposa...

WASTEWATER TREATMENT PRESENTATION BY SHRIPAD NIMBHORKAR NIMBHORKAR STUDY NOTES 1  WASTEWATER TREATMENT What is wastewater ? Water which is used in process and comes out for disposal This may be Sewage –Domestic industrial wastewater –Effluent NIMBHORKAR STUDY NOTES 2  WASTEWATER TREATMENT Why treat wastewater ? 1. Not to harm Environment 2. Save water by reusing treated wastewater 3.Decrease water footprint of product and increase the product value 4. Profitability –save on water purchased 5. Meet the regulatory requirements NIMBHORKAR STUDY NOTES 3  WASTEWATER TREATMENT Why treat wastewater ? 1. Not to harm Environment The contaminants in water can harm the Environment and finally if the same pollutes ground wate it is problematic to human health as well as for the other uses. The bacterial contaminants can spread the pathogens and increase in diseasesspread.Remember During monsoon maximum cases are of drinking water contamination related problems. NIMBHORKAR STUDY NOTES 4  WASTEWATER TREATMENT Why treat wastewater ? 2. Save water by reusing treated wastewater i) Water cost is increasing over the peiod affecting the profitability 2.Water availability is a big problem.Many cities are having once a week or twic a week water supply 3.3.Tanker water supply does not have quality control as no pretreatment is given 4.Mass migration of nillage population due to water scarecity NIMBHORKAR STUDY NOTES 5.  WASTEWATER TREATMENT Why treat wastewater ? 3.Decrease water footprint of product and increase the product value Water footprint is a measure of water utilization of product.In process how much water you need as well as what quality of water you discharge are factors for water footprint.World over it is agrred to reduce water footprint of product.Thus for Corporate policy water footprint is a major parameter in purchase policy.Marketability in future will be dependent on water footprint. NIMBHORKAR STUDY NOTES 6  WASTEWATER TREATMENT Why treat wastewater ? 4. Profitability –save on water purchase Cost of water used is significant in profitability and Hence you find today industries are planning water reuse while planning the plant. Work out some examples.. NIMBHORKAR STUDY NOTES 7  WASTEWATER TREATMENT Why treat wastewater ? 5. Meet the regulatory requirements As you are aware the factory owner has to have Consent from Pollution Control Board before getting other resources like Electricity etc Water Pollution Control consent is given by State or Central Pollution Control Boards after examination of Wastewater Treatment to the standards stipulated.. NIMBHORKAR STUDY NOTES 8  WASTEWATER TREATMENT Why treat wastewater ? The water used in the process gets contaminated and as per legal require,ent wastewater need to meet the water quality as per the standards stipulated. Hence it is must to treat the wastewater. Similarly reuse application govern the water quality requirement Hence you will need treatment.. NIMBHORKAR STUDY NOTES 9  WASTEWATER TREATMENT Why treat wastewater ? The water used in the process gets contaminated and as per legal require,ent wastewater need to meet the water quality as per the standards stipulated. Hence it is must to treat the wastewater. NIMBHORKAR STUDY NOTES 10  WASTEWATER TREATMENT Why treat wastewater ? Water Quality understanding Water for drinking is stipulated as per IS 10500 is followed.which has 35 parameters and levels. Water drank by us is not the same as what we drink.The quality is changed which is easily noticeable in color, smell etc without going into all parameters. NIMBHORKAR STUDY NOTES 11  WASTEWATER TREATMENT Why treat wastewater ? Water Quality understanding The treated water quality for disposal is stipulated by the Pollution Control Board in Consent. NIMBHORKAR STUDY NOTES 12  WASTEWATER TREATMENT Why treat wastewater ? Water Quality understanding For sewage –Domestic wastewater for Example pH,TSS,BOD,COD and O & G are normally stipulated. pH 7-8 BOD 10 mg/lt COD 100 mg/lt TSS 50mg/lt and O & G 10 mg/lt ia example.However these parameters differ depending on pollution control Board policy for the regional NIMBHORKAR STUDY NOTES Water Quality Policy. 13  WASTEWATER TREATMENT Why treat wastewater ? Water Quality understanding For Industrial discharge water quality parameters are based on Industry production and production process likely contributing natural water quality parameters 5. Meet the regulatory requirements. NIMBHORKAR STUDY NOTES 14  WASTEWATER TREATMENT Why treat wastewater ? Contaminants Can be Organic or Non Organics Organics – Sewage, Distillery,Food Processing, Sugar, Pharma ,Textile , etc Inorgnic –Metal processing, Pharma , Electroplating,etc. NIMBHORKAR STUDY NOTES 15  WASTEWATER TREATMENT wastewaterTreatment is planned based on the contaminants in the wastewater Inorganics – Depending on the nature and reactivity Organics – Normally Biological due to lowcost but some time it is combined with other process. NIMBHORKAR STUDY NOTES 16  WASTEWATER TREATMENT wastewaterTreatment is planned based on the contaminants in the wastewater The treatment may require or generally preceeded by pretreatment which may be screening/ grit removal/pH correction/ Equalition or chemical treatment depending on specific effluent. NIMBHORKAR STUDY NOTES 17  WASTEWATER TREATMENT Primary Wastewater Secondary Treatment Tertiary Processes Advanced Screen/Grit Activated Sludge Chlorination UF/RO /MEE removal Process Filteration Sand/Carbon pH correction MBBR Equalization SBR. Oil Removal MBR Anaeroic Digesters Primary Settling NIMBHORKAR STUDY NOTES 18  WASTEWATER TREATMENT Screening Removal of Coarse/ fine solids Coarse Screens & fine Screens Manually operated 0r mechanically operated Remove solidsto prevent pumps/other equipment dmage & interfere with subsequent processes NIMBHORKAR STUDY NOTES 19  WASTEWATER TREATMENT Grit Removal Manually operated 0r mechanically operated Remove Grit specifically in sewage treatment & prevent its interfere with subsequent processes NIMBHORKAR STUDY NOTES 20  WASTEWATER TREATMENT Oil Removal Manually operated 0r mechanically operated Remove oil & prevent its interfere with subsequent processes NIMBHORKAR STUDY NOTES 21  WASTEWATER TREATMENT Equalization-To achieve uniform characteristics for further treatment surface mixing or air blowers with diffusers /pump aerators uniform characteristics & prevent its interfere with subsequent processes NIMBHORKAR STUDY NOTES 22  WASTEWATER TREATMENT Settling /clarification To remove TSS before further treatment Mechanical sludge removal –Clarifiers Manual- gRavity settling tanks Various types of clarifiers are available Clarifiers/clariflocculators/ circular/ Rectangular /PPS/Tube settles etc NIMBHORKAR STUDY NOTES 23  WASTEWATER TREATMENT Biological Treatment is for for Organic removal.Secondary Treatment This may be attached growth process where bacteria rare attached to media –Trickling Filters /Biofilters However, most practiced today is Suspended growth system where bacteria are in suspension with wastewater to be trated.Activated sludge is most common and earlier method NIMBHORKAR STUDY NOTES 24  WASTEWATER TREATMENT The organic matter reduction is achieved most economically in Bioreactor where wastewater organics are biodegradable.The common historical biological method is Activated Sludge Process.The Extended Aeration Activated sludge Process has the best reported efficiency. NIMBHORKAR STUDY NOTES 25  WASTEWATER TREATMENT Activated sludge Process is most common and world over followed biological process for removal of organics in wastewater.The wastewater has organics and bacterial mass Culture in suspension.Oxygen needed for biological growth process is provided by surface aerators or by diffused areration. The biomass is settled in secondary clarifier.Part of sludge is taken back to aeration tank to keep microbial concn cionstant and excess biosludge is wasted. NIMBHORKAR STUDY NOTES 26  WASTEWATER TREATMENT. Components of ASP Bioreactr , Surface Aerators OR Air Diffusers & Blowers.Settler-Clarifier.Sludge Recirculation Exces sludge wastage to dewatering SDB/Centrifugr3 NIMBHORKAR STUDY NOTES 27  WASTEWATER TREATMENT Activated Sludge Process Clarifie r Bioreactor Waste excess sludge s RAS RAS Pumps NIMBHORKAR STUDY NOTES 28  WASTEWATER TREATMENT MBBR Process MBBR is also termed as fluidized bed bio reactor. The Media which is Plastic media having high surface to volume / wt ratio. This may be Structural Plastic rings Hexagonal Plastic or modified plastics to get high surface area to volume ( or Weight) ratio The media is for retaining the bacterial mass so that bacterial population is always retained and does not get wash out.It also permit to have higher biomass wrt to other suspended growth processes like ASP and its modifications. The media moves freely in the top layer and protected from escape by having suitable screen at outlet NIMBHORKAR STUDY NOTES 29  WASTEWATER TREATMENT Components of MBBR 1. Media. 2. Bioreactor 3,Air Diffusers & Blowers 4.Settler 5.Sludge Recirculation NIMBHORKAR STUDY NOTES 30  WASTEWATER TREATMENT Activated Sludge Process Plastic Media Clarifie r Bioreactor Waste excess sludge s RAS RAS Pumps NIMBHORKAR STUDY NOTES 31  MOVING BED BIOREACTOR WASTEWATER TREATMENT MBBR Process Advantages /Disadvantages Sr No Advantages Disadvantages 1 Reduced Volume /land footprint Breakage of Media 2 Sustain MLSS ,less reseeding More Oxygen required to maintaoin CSTR 3 Good Efficiency for low &n Medium Increased media cost & strength ww replacement/washing 4 Low cost compared to EASP NIMBHORKAR STUDY NOTES 32  MOVING BED BIOREACTOR WASTEWATER TREATMENT SBRR Process SBR -SEQUENTIAL BATCH REACTOR NIMBHORKAR STUDY NOTES 33  SEQUENTIAL BATCH REACTOR 2 34 WASTEWATER TREATMENT SBRR Process Bio-Reactor Raw Chlorination Wastewater Treated Wastewater Multi Grade Grit Filter Feed Sand Filter chamber Tank SCREEN Bio-Reactor Air Blower NIMBHORKAR STUDY NOTES  SEQUENTIAL BATCH REACTOR 2 35 WASTEWATER TREATMENT SBRR Process 1. The batch reactor acts as Equalization tank, Bioreactor and Settling tank 2.The sludge wastage is from bioreactor when Excess sludge is generated. 3, The post treatment of Sand filteration is generally given. To ensure no biomass is passed out.Disinfection is carried out in filter feed tank. NIMBHORKAR STUDY NOTES  WASTEWATER TREATMENT MBR Process Membrane Bioreactor Membrane Bioreactor has two section Anoxious and Aerated. Anoxious Chamber is a small and has 20 % volume provided.This chamber has a slow stirrer to keep solids ( Biomass ) in suspension Aerobic Chamber is the volume provided for Bioreactor to degrade organics.SRT range is 10-20 days and HRT 4-8 hrs MLSS range upto 5000 -20000mg/lt Air provided with coarse bubble diffusers. In Insitu Configeration ,allowance is made for volume occupied NIMBHORKAR STUDY NOTES by membrane module. t 36  MEMBRANE BIOREACTOR (MBR) Membrane Bioreactor ( MBR ) has Bioreactor and UF Membrane There are two configuration available In-situ Membrane where UF membrane is in Bioreactor And Ex situ where UF membrane is installed outside Bioreactor NIMBHORKAR STUDY NOTES 37  MEMBRANE BIOREACTOR (MBR) BIOREACTOR UF BIOREACTOR -AEROBIC MEMBRANE -ANOXIOUS FINE SCREEN RAW EFFLUENT AX AE 38 DIFFUSERS AIR BLOWER NIMBHORKAR STUDY NOTES  MEMBRANE BIOREACTOR (MBR) WASTEWATER TREATMENT SBRR Process BIOREACTOR BIOREACTOR -AEROBIC -ANOXIOUS FINE UF SCREEN MEMBRANE RAW AX EFFLUENT AE 39 DIFFUSERS AIR BLOWER NIMBHORKAR STUDY NOTES