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Engineering on environment presentation .pptx
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- 2. OBJECTIVES OF WATERTREATMENT “To remove harmful microorganisms or chemicals, thereby preventing the spread of disease in order to supply clean and safe water for public demand”
- 3. ’ŸATEE iÑOURCE Water sourcecould be River Lakes Groundwater; most likely better quality than surface water Rainwater ++/ Dam Raw water quality varies with the source, and if the source is surface water, the quality vary seasonally, particularly with flooding, upland and lowland, etc
- 4. Table 11.5 Typicalraw water analysis Clear 580 7.3—7.9 4to Conductivity, pS/cm p TDS, ppm Cations mg/L as CaCOt Ations mg/L as CaCO, C1* 5 2 F HCO, NO, 40 500 2fi0 10 Adapted fit›m LORCH. 1987 Slightly yeltow 150 Turbid 915 105 Ca'* 250 MJ“ 75 15 Na" 25 35 K* Mn“ Fe“ 30 15 6 30 640 Turbid 1000—7000 2250 S1000 700—50(D 36 21X) 8 b 350 150—500 73 1330 I50—2000 257 10 300 15.4 350 0.002 0.06 200 75 200 125 <2OQO 502 20 500 175 < 1500 162 2850 2.05 10 10-20 24.5 20 50 170
- 5. Table I.‘/ Co›oparig@/OFsurface water nnd groundwater qmmjj Tucbi+I end s«sp<•a<dsolids # g g '# s si v a cwbon dioxide Oi$mlvodw*ygrn Anurinnia Hydrogen wlphidc Silica Nioa4e Yancs *'i* x"i , rainf®ll, cffiugpts, cm Some Ifonc t7flen near mtt«gtio«, urgpt ppp poiluted Only in poliuicd water 8 !^'°0 MaF' ’e high mms Gmundvaier Alozys some 1.18ualIy iO'•v. rct{£1irrs yrgtion Lcvcls !uund l‹› be in-creating due Io ag iculrurcl Peliutinn
- 6. Table J1.4 Excerptsfj•n4ntUS pfi:•••w zJnking water standards Health effects Inorganic chmicals Cadmium Chmmium Copper Lead Total (nitrate and ni08t8) Total colifonns Turbidity Kidney Line /Lidncy, skin end digestive s}'st<m Sinmach and intestinal distress, Wilson's disease ygp and periphcral ncyous systcm d8rHRge: kidney; highjy toxtc to inlets axd pugnan women Kidnry, nervous system Methanoglobinacmia, “blue-baby sr•d tc' Methp Ogl9bi 'B¢ i ’blue-bed' syndrome' Not app{iCabJe Stomach cramps, inlcstirlal distms$ ( iardi8sis) Legionnaires' disease (pneumonia). P0ntii ftV0f indicators of 0.1 TT '^*° typhoid fever. cholera and other diseases. Co!iforms ^ disinfecion Interferes. with disrnCttOD Gastr•eritrriiis (intestinal distress) Possible i rem in blood pressure in susceptible individuals t n = tieitr»eni technok›gy r»qui< 0.002 10 None (*0 md:'L
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- 8. WATER TREATMENT PROCESSES Tnble11.8 Clzaaes of water treatment Class No treatmmt Disinfection only c Standard water treatment source Some bowholc water Some borehole water Lowland rivers and reservoirs Some rutaJ supplies the and Mn) Colour removal Trace element mmovat Industrial waier Algae wmovel Gzganics removal
- 9. Primary lnia£e Cause scn¢cging Fire .wzœnifig DisinfzciiunDisinf tiun AdiWd trcømm Di srihuiion Seuimìimtioo Aeraikin Chemical prc•irratirteni Ae*etion Coagulation and mizing Łmcot*tion Sedirru:rsaüun C uleiiøa znd miviøg Łmculakn S t i r s røaiinn Yes Fluoù tion
- 10. SELE(?TION OF 'I'REATMENTPROC E5iSEFi Selection of the set of Treatment Processes will be based on : Sources of water intake Characteristic of water Detailed raw water quality analysis for a minimum of one year, or longer, at periods of high, low and medium flows. The parameters to be looked at all those listed in the legislative standards Cost Suitability of the processes for removing particulate impurities. Example: Turbidity; suitable process might be coagulation , sedimentation or filtration For pathogen, pre or post chlorination, UV, ozone, or chloramines
- 11. Table It.9 Recommendedtreatment for specific impurities Parameter Treatment process Floating matier Suspended matter Algae Turbidity Colour Tasie and odour Hardness Iron and manganese > I mg/L < 1 mg/ L Pathogens, MPN/ 100 m1 < 20 2 0 —100 > 100 Free ammonia Coarse screens. fine screens Microscreens Microscreens, pre-chTpnnation, carbon adsorpt i‹›n. rap d filtration Coagulation, sedimentation, post-chtorinat on Fnccu1aiion, ccaguattnn. fi)rrptinn Acti 'ated carbon Coagulation. filtration, lime softening Pte-chlonnation A<rztion. coagulation. filtration Pnst-chlorina ion Coagulation/fiTWaiion/pnst-chIonnption Pre-chonnation Fr agulatinn/fiTrmtinrt,+gnst-chlonnahnn Post-chorinatinn Adsorption
- 12. WATER TREATMENT PROCESSES oPretreatment of water • Screening • Storage, Equalization & Neutralization • Aeration • Chemical pretreatment o Sedimentation, coagulation and flocculation o Filtration • Slow Sand filtration • Rapid Gravity filters o Disinfestations • Chloraminee • Ozone • UV radiation • Chlorination o Fluoridation o Advance Water Treatment • Iron & Manganese Removal • Water Softening by Chemical Precipitation • Ion Exchange • Adsorption • Chemical oxidation • Membrane Processes
- 13. SURFACE WATER TREATMENT Typicaltreatment plant for surface water Screening and grit removal Primary sedimentation (settling/clarification) Coagulation(Rapid mixing) Flocculation Secondary sedimentation Filtration Sludge processing Disinfection
- 14. GROUNDWATERTREATMENT Typical treatment plantfor groundwater Aeration Flocculation/precipitation Sedimentation Recarbonation Filtration Disinfection Solids processing