工业用水和废水处理与保护

Soundararajan .S Holtec Consulting Pvt.Ltd.Gurugram,Haryana,India TABLE OF CONTENT 1.Fresh water,Seawater,wastewater constituents and their broad treatment 2.System and Equipment.3.Zero Liquid Discharge plant (ZLD).4.Water Economics and Norms fixed by authorities.5.Liquid effluent discharge standards.6.Water quality standards.7.Water quality for power plant make-up and cooling tower make-up.8.Automation and control.9.Recommended sizing criteria for equipment and piping. OBJECTIVE 1.Necessity of quality water for cycle make-up and cooling process for industry. 2.Conservation of water – Recycling of maximum quantity of wastewater3.Effluent Discharge norms fixed and adherence to norms4.Commitment of industry to environmental protection which is paramount and all 5.At Holtec, lots of study and research is done to meet the above requirements andthis presentation depicts various water sources, technology we have adopted for DIFFERENT TYPES OF INPUT WATER FORBOILER MAKE-UP TYPICAL WATER TREATMENT SCHEME WITHPOST DM PLANT COMPARISON OF DM AND EDI TECHNOLOGY Considering above, EDI is preferred over conventional DM. SEAWATER DESALINATION Energy recovery device shall be used to pressurize RO feed water with RO reject water DESALINATION PLANT MATERIAL Low Pressure Pipe - Intake-HDPELow Pressure Pipe - In the Plant-GRP withvinylester resin or GRE with Epoxy Resin.High Pressure Pipe - Super duplex PREN Typical Scheme for Seawater Desalination Typical Scheme for Seawater Desalination Different Types of Industrial Wastewater and TheirTreatment TypicalIndustrial Wastewater Treatment Schemeand Zero Liquid Discharge Typical Block Diagram for Effluent TreatmentPlant Requiring Biological Treatment Typical Block Diagram for Sewage Treatment Plant SYSTEM AND EQUIPMENT PreTreatment 1.Aeration Equipment -Cascade or Gravity Aerators,-Spray/Fountain Aerators 2.Clarifications Equipment -High-rate solid Contact clarifier-Tube settlers Removes-Suspended solids with outlet TSS less than 20PPM.-Turbidity with outlet turbidity less than 20NTU. SYSTEM AND EQUIPMENT 3.Filtration Equipment -Multi grade or dual media filter-Activated Carbon filter Removes-Multigrade filter TSS less than 5 PPM-Turbidity less than 5 NTU. 4.Oil and Grease Removal EquipmentEquipment -Dissolved Air Floatation (DAF)-Walnut Filter Removes-Oil and grease to very large extent Membrane Based System – 4 Different Types 1.Micro Filtration:Fully automatic 2.Ultra Filtration:Fully automatic ultra filtration system with hollow fiber membrane madeof Polysulphone or Polyether Sulphone or PVDF. 3.Nano Filtration:Fully automatic or semi-automatic plantRemoves -Diatomic salts 4.Reverse Osmosis System Fully automatic or semi-automatic system Ranges of Filtration Processes up to ReverseOsmosis Post RO Treatment -Following are the Configuration 1.DM Plant-SAC, SBA Removes -Cation and anion in the water with sodium slippage less than 1 PPM in SAC and 2.Polishing Unit -Mixed bed Removes -Residual cation and anion from SAC and SBA to a very low level like conductivityless than 0.2 micro-Siemens/cm and silica less than 0.02 ppm, iron less than 0.01 PPM. -Sodium and potassium to less than 0.01 PPM etc. 3.EDI – Combination of membrane and resin Removes -Residual cation and anion from SAC and SBA to a very low level like conductivityless than 0.2 micro-Siemens/cm and silica less than 0.02 ppm, iron less than 0.01 PPM. -Sodium and potassium to less than 0.01 PPM etc. WATER ECONOMICS AND NORMS FIXED BYAUTHORITIES Power plant 3.0m^3/MWH is the limit of Fresh Water Intake.Zero liquid discharge to be followed.Sugar plant can discharge only 100 liters/ton of cane crushed.Cement plant shall go for ZLD. All efforts to be made for ZLD.95 to 97% of wastewater to be re-used.Treated sullage and sewage water can also be re-used. The above guideline led to water conservation by utilizing maximum extent of LIQUID EFFLUENT DISCHARGE STANDARD-CPCB 1.PH 5.0-9.0% , 6.5-8.5%2.Total suspended solids not to exceed 100PPM.3.Oil and grease not to exceed 10 PPM4.Temperature should not exceed 5 degree over the Intake water temperature.5.Total Residual Chlorine 1.0 PPM max6.BOD 30 PPM7.COD 250 PPM8.TDS 2100 PPM STP PLANT DISCHARGE 1.BOD - 10 PPM max2.COD - 50 PPM max3.TSS - 100 PPM max4.PH - 6.5 to 8.5 Note-Storm water is not allowed to be mixed with effluent, treated sewage water, WATER QUALITY STANDARDS Feed water, Drum water standardFeed water , Drum waterDrinking waterFor cooling water make up -IS 10496 (High Pressure)-IS 10392 (Low and Medium Pressure)-IS 10500 BOILER MAKEUP WATER QUALITY PH at 25 degree C(After PH correction) - 8.5 to 9.2Conductivity at 25 degree - < 0.2 micro-Siemen/cmTotal Iron - < 0.01 PPM Recommended Cooling Tower makeup water-With Chemical treatment done in the Cooling Circulating Water TDS can go as high as- 4000PPMHardness asCaco3- 2200PPMAlkalinity as Caco3- 250 PPMCalcium as Caco3- 1200 PPMChloride as Caco3- 1000 PPMSu