Impurities inWastewater & Problems Caused by It By: Nikhil Sharma BE/8034/09
What is Waste Water?Wastewater is any water that has been adversely affected in qualityby anthropogenic influence.It is usually produced from by-products of otherwise purposefulhuman activities.Classification: Industrial Waste Water Waste Water Sewage (Domestic Waste Water)
Wastewater quality indicators or how to determine the quality of the waste water?The BOD5 test:BOD measures the rate of oxygen uptake by micro-organisms in asample of water at a temperature of 20°C and over an elapsed periodof five days in the dark.
Origins:•Human Waste (Blackwater)•Surface Runoff: •Detergents •Disinfection by-products •Insecticides and herbicides •Petroleum hydrocarbons •Ammonia from food processing waste •Fertilizers containing nutrients(Nitrates and Phosphates)•Heavy Metal Industries•Thermal Power Plants (Heated Water)•Nuclear Power Plants•Deep Sea Mining•Oil Spills•Heavy Metal Mining
Consequences:•Ocean Acidification: Oceans are carbon sinks but cannot copewith increase in CO2 .•Eutrophication•Bio Magnification/Bio Accumulation•Increase in BOD (Biochemical Oxygen Demand)•Marine Debris•Still Water Bodies•Reduction of natural reserve of potable water Fig: Acidification of the ocean has caused the fringing of coral reefs in the MaldivesFig: Direct discharge of Fig: Polluted Lagoon Fig: Marine Debrisheavy metals to waterbodies
Problems Arising:•Toxic waste reaches humans through animals upon consumption.•Great loss of wildlife.•Spread of water borne diseases. (ex. Malaria,Cholera,Jaudice,etc.)•Excessive water treatment required before water is fit forconsumption•Pressure on groundwater reserve leading to decrease in watertable.•Presence of choliform microorganisms leading to health problems•Consumption of heavy metals (Hg,Pb,As,Cd,Ni) causing birthdefects and other disorders (ex. Mercury causes Mina Marta, Leadcauses Akai Akai•Oil spills lead to many complications in marine animals and lifedirectly or indirectly dependant on it
Fig: Dissolved Air flotation System•Industrial waste water treatment plant •Cooling ponds: Through evaporation, convection, and radiation •Dissolved air flotation system •On site water treatment plant for large industries