Saran's Learn Microbiology

METHODS FOR SMALL SCALE SEWAGE TREATMENT   1) CESSPOOLS OR CESSPIT In many homes, human waste is emptied into underground Cesspools. Cesspool is an underground construction consisting of Concrete cylindrical rings with pores in the walls of the ring. Cesspool Sewage water passes into the Soil through the bottom and pores of the Cesspool, while Solid waste accumulates on the bottom. Microorganisms, especially Anaerobic bacterial species, digest the Solid matter into Soluble products that enter the soil and enrich it. The amount of breakdown products exceeds, it forms Thick layers which need to be cleaned by using Strong acids. Dried bacterial preparation of Bacillus subtilis or Yeast cells or Enzymes should be added at intervals. These accelerate the decomposition of sludge deposited at the bottom of cesspool. The minimum size Cesspool for a habitable dwelling is 18000 litres and on average this Cesspool tank will require emptying once completely filled or every 20 - 25 days.

 SEWAGE TREATMENT Sewage is used water and the wastes it contains. It is about 99.9 % water and about 0.1 % solid or dissolved wastes. The Dissolved wastes include (i) Household wastes (Human feces, Detergents, Grease, and anything else people put down the drain or Garbage disposal unit); (ii) Industrial wastes (Acids & other chemical wastes and Organic matter from Food processing plants) and (iii) Wastes carried by rainwater that enters sewers. Wastewater contains a variety of Contaminants, including Suspended solids, Biodegradable & Non-biodegradable Organic and Inorganic compounds, Toxic metals and Microbial pathogens that pose a health risk. A sewage treatment plant is required for all Residential and Commercial areas. Sewage treatment, also known as Wastewater treatment, is used to remove contaminants from municipal and industrial wastewater. Various physical, biological, and chemical processes are used to treat Wastewater. Sewage treatment can be done by two methods. They