Product Details  waste water treatment  Water Treatment The raw sewage must be treated before it is discharged into the river stream. The extent of treatment required to be given depends not only upon the characteristics and quality of the sewage but also upon the source of disposal, its quality and capacity to tolerate the impurities present in the sewage effluents without itself getting potentially polluted. The layout of conventional wastewater treatment plant is as follows: Indian Standards for discharge of sewage in surface waters are given in the table below.Indian Standards for Discharge of Sewage in Surface WatersCharacteristic of the EffluentTolerance limit for Discharge of Sewage in Suface Water SourcesBOD520 mg/LTSS30 mg/LThe unit operations and processes commonly employed in domestic wastewater treatment, their functions and units used to achieve these functions are given in the following table:Unit Operations/Processes, Their Functions and Units Used for Domestic Wastewater TreatmentUnit Operations/ProcessesFunctionsTreatment DevicesScreening Removal of large floating, suspended and settleable solids Bar racks and screens of various descriptionGrit Removal Removal of inorganic suspended solids Grit chamberPrimary Sedimentation Removal of organic/inorganic settleable solids Primary sedimentation tankAerobic Biological Suspended Growth Process Conversion of colloidal, dissolved and residual suspended organic matter into settleable biofloc and stable inorganics Activated sludge process units and its modifications, Waste stabilisation ponds, Aerated lagoonsAerobic Biological Attached Growth Process same as above Trickling filter, Rotating biological contactorAnaerobic biological growth processes Conversion of organic matter into CH4 & CO2 and relatively stable organic residue Anaerobic filter, Fluid bed submerged media anaerobic reactor, Upflow anaerobic sludge blanket reactor, Anaerobic rotating biological contactorAnaerobic Stabilization of Organic Sludges same as above Anaerobic digestor