Etp intro
- 1. EFFLUENT TREATMNT PLANT (ETP) DR. Banupriya D,
- 2. CONCEPT OFETP Effluent treatment Plant covers the mechanisms to treat waste water that is contaminated by anthropogenic industrial or commercial activities prior to its releaseinto the environment or its re-use. ETP treats water and make them free from suspensions, colloids or any dissolvedform.
- 3. WHY DO WE NEED TO TREAT EFFLUENT? To prevent groundwater pollution and improve recharge To prevent sea shore pollution To prevent soil contamination To prevent marine life Protection of public health For agriculture purpose For industrial recycle
- 4. NEED OF ETP IN INDUSTRY Manufacturers face strict regulations on discharge and waste. Non-compliance can lead to expensive fees and operations interference. A wastewater treatment help them to: Stay in compliance Reduce transportation and treatmentcosts Reduce supply costs by recovering production materials out ofthe waste.
- 5. MAJOR TREATMENTUNITS IN ETP Primary Treatment Sedimentation/ Settling tank Clarifloculator Equalization Tank Neutralization Tank Preliminary Treatment Screens Detritor/scrapers Grit Chamber Skimming Tanks Aeration
- 6. CONT… • Secondary Treatment Activated Sludge Process (ASP) Trickling Filter Aerated Lagoons UASB Multiple Evaporator (ME) Plant Rotating Biological Contactors (RBC) • Tertiary Treatment Sand/ Membrane Filters Activated Carbon Filters Disinfection Ion-exchange/ESP Nutrient Removal
- 7. EQUALIZATIONTANK Some industries produce different types of wastes, having different characteristics at different intervals of time. Hence, equalization tank is used to mixed different type of effluent thoroughly to produce homogenous and equalized effluent foruniform treatment.
- 8. Equalization by Surface Motors Different Inlet in Equalization Tank
- 9. NEUTRALIZATIONTANK Neutralization tank is used to provide treatment to highly acidicor highly alkaline effluent trough neutralizing pH by addition ofchemicals. Acidic effluent is usually treated with lime stone or lime-slurry or caustic soda, depending upon the type and quantity of effluent. Alkaline effluent is neutralized by sulphuric acid or CO2 or wasteboiler flue gas.
- 10. PRELIMINARY TREATMENT Preliminary treatment removes gross solids and materials that can be easily collected from the effluent and can damage or clog the pumps These are in-organic materials and insoluble organic pollutants It depends upon the characteristic of effluent that is to be treated.
- 11. PRELIMINARY TREATMENT- SCREENS Screens are used for removal of large floating and sub-mergedmaterial such as plastic, paper pieces, rubber, etc. from effluent. Screens are classified in number of ways as follows: Based on the size of opening- such as coarse, medium and finescreens. Depending upon shape- such as disc, drum, band,etc. Based on method of cleaning- such as mechanical ormanual.
- 12. Mechanical medium screen Fine screen Corse bar screen
- 13. PRELIMINARY TREATMENT- DETRITORS/ SCRAPPERS Detritors are shallow circular ponds used in pre-treatment plants with the purpose of grit removal. Chain or blade type Detritors/scrappers are utilised in anadjacent channel into which the collected grit is transferred.
- 15. PRELIMINARY TREATMENT- GRIT CHAMBER Grit Chamber is used for removal of inert inorganic material consist of sand, ash, cinder, silt, clay, glass pieces, etc. It provides safeguard against ant damage to pumps, pipes andother equipments by avoiding settling in pipe bends and channels. The eliminated material is collected from chamber and used forland-filling, road making and on sludge dryingbeds.
- 16. PRELIMINARY TREATMENT- SKIMMING TANK Skimming Tank is used for removal of oil and grease consist of fats,waxes, fatty acids, soaps, mineral oils, etc. present in emulsified condition in effluent. The efficiency can be improve by aeration, chlorination or vacuum floatation.
- 17. Skimming Tank with separated oil & grease at top Collection of separated oil & grease at edge
- 18. PRIMARY TREATMENT Primary treatment consists of temporarily holding the sewage in a inert basin where heavy solids can settle to the bottom while oil, grease and lighter solids float to the surface. The settled material go for sludge treatment and floating materialsare skimmed off. The remaining liquid is passed to secondary treatment. Tanks are usually equipped with mechanically driven scrapers that removes the sludge at the bottom At this stage, over 70% of the suspended solids and 40% of the BODis removed from effluent.
- 19. SEDIMENTATION TANK(CLARIFIER) Sedimentation Tank are designed to remove suspended particles that are heavier than water through gravitational force by reducing water velocity. 1. Clarified supernatant leaving the top of the sedimentation tank(underflow). 2. Concentrated sludge leaving the bottom of the sedimentation tank(overflow). An efficient sedimentation tank can remove about 90% of SS and 40% organic matter with two hour of detention time.
- 20. Circular Primary Settling Tank Rectangular Settling Tank Working of Settling Tank
- 21. COAGULATION, FLOCCULATION Coagulation Coagulation is the conversion of finely dispersed colloids into a smallfloc with the addition of coagulates. Flocculation The purpose of flocculation is to bring coagulated particles togetherby mechanically inducing a velocity gradient within aliquid. Organic polyelectrolyte flocculation aids are effective in promotingsoluble solids removal. Flocculation improves the removal of finely divided solids bygravity settling.
- 22. CLARIFLOCULATOR Clarifloculator consist of coagulation (chemical) and flocculation (mechanical) process. Employed when finely divided SS and colloidal particles can not be efficiently removed by simple sedimentation. In such cases chemical assistance is taken. The most common coagulants are Alum, hydrated lime, ferric chloride,ferrous sulfate and PAC (Poly aluminum Chloride).
- 24. SECONDARY TREATMENT Secondary treatment is a biological treatment of effluent which istypically performed by indigenous, water-borne micro-organisms Secondary treatment removes dissolved and suspended organic (bio- degradable) matter by consuming it as a food and convert it into new cell mass, energy and CO2. The most common micro-organisms are bacteria (aerobic or anaerobic), protozoa and rotifers; least common are fungi andalgae. After secondary treatment almost 70-90% of BOD and 80-90% of dissolved solids are removed from effluent.
- 25. TRICKLINGFILTER In trickling filter treatment, wastewater is sprayed through sprinkling rotating arm on circular beds consist of 3-10 ft deep coarse media (of crushed stones, gravels or synthetic material). Microorganisms get attach and grows on the media and resultsin formation of film of micro-organisms called zoogloeal film. It is simple to operate and give almost 80-90% of BOD removal with high quality effluent.
- 26. Trickling Filter with rotating arm Working of Trickling Filter Media bed of gravels and stones
- 27. ACTIVATED SLUDGE PROCESS (ASP) Effluent is aerated in a reaction tank consist of microbial population in suspension form. The bacterial flora grows and remains suspended in the form of a floccalled activated sludge. A part of sludge is recycled for the same tank to provide an effective microbial population for a fresh treatmentcycle. Industrial ww require 6 to 24 hours of aeration though which almost90- 95% of BOD can be removed.
- 28. ASP combined with filtration Aeration Tank in ASP
- 29. UP-FLOWANAEROBIC SLUDGE BLANKET REACTOR (UASB) UASB system is a three phase settler which separates sludge, liquidand biogas in same tank under high turbulence without occupying large space. Organic matter is degraded under anaerobic conditions by microbes producing methane and CO2. More effective than conventional aerobic process, produces only 5-10% of sludge.
- 30. UASB working Mechanism UASB Tank with gas holder doom
- 31. TERTIARYTREATMENT Tertiary treatment is the final treatment, meant for ‘polishing’ the effluent and removal of pollutants not removed in primary and secondary treatment. Also removes organic materials contributing BOD, COD, color, taste, odor; bacteria, viruses. Preferred when treated water is need to be reuse or discharge is intoa highly sensitive or fragile ecosystem (estuaries, low- flow rivers, coral reefs, etc).
- 32. CONT… Tertiary treatment add additional cost to the treatment process but produce high quality effluent If it is sufficiently clean, it can also be used for groundwater recharge.
- 33. FILTRATION Filtration is process of removing particulates and bacterial impurities that could not be removed in earlier treatment, from water by passing it through a porous medium. It is also used to reduce odor and color by arresting them in filter media. Selection is totally depend upon characteristics of ww, efficiency of absorbent, flow rate and pollutant to be removed fromww.
- 34. Sand Filters Based on Filtration Rate Pressure Filters Gravity Filters Rapid Sand Filter SlowSand Filter Based on Filter media Material Based on Depth of Filter media TYPES OF FILTERS Anthracite Filters Metal Fabric Filters Diatomaceous Earth Filters Deep Granular Filters Pre-coat Filters
- 35. ACTIVATED CARBONFILTERS ACF are used to remove free chlorine, organic residues, toxic heavy metal ions and color from ww. Most common adsorbents used are activated carbon, peat moss, brown coal and other cellulose materials. This treatment not only improves taste of water but also protectsother water treatment units such as reverse osmosis membranes and ion exchange
- 36. Different media used for ACF ACF Tubes or channels
- 37. ION-EXCHANGE This treatment is used for removal of toxic materials and recoveryof valuable materials from effluent. Ion-exchange is only economical when recovered material is reused. Cr, Ni, Phosphate and H2SO4, Cu, Pb, Hg and removal of cyanides from wastewater after Cr recovery.
- 38. ETP Plant with Advance Treatment