Page 60 - GRIHA Manual Volume IV - Introduction to National Rating System

Building planning and construction 51

Table 2 Unit operations and treatment systems used to remove the major contaminants
Contaminant Unit operation or treatment system
Suspended solids Sedimentation
Screening
Filtration variations
Floatation
Chemical-polymer addition
Coagulation/sedimentation
Land treatment systems
Biodegradable organics Activated-sludge variations
Fixed-ilm:trickling ilters
Fixed-ilm:rotating biological contractors
Lagoon variations
Intermittent sand iltration
Land treatment systems
Physical-chemical systems
Pathogens Chlorination
Hypochlorination
Ozonation
Land treatment systems
Nutrients
Nitrogen Suspended growth nitriication and denitriication variations
Fixed-ilm nitriication and denitriication variations
Ammonia stripping
Ion exchange
Breakpoint chlorination
Land treatment systems
Phosphorus Metal-salt addition
Lime coagulation/sedimentation
Biological-chemical phosphorous removal
Land treatment systems
Refractory organics Carbon adsorption
Tertiary ozonation
Land treatment systems
Heavy metals Chemical precipitation
Ion exchange
Land treatment systems
Dissolved inorganic solids Ion exchange
Reverse osmosis
Electrodialysis
Source: Metcalf & Eddy Inc. 1979, Wastewater engineering: treatment, disposal, reuse, Tata McGraw Hill, New York