Tag: microbial pollution control

Sewage sludge is a product of wastewater treatment. Once treated, sewage sludge is then dried and added to a landfill, applied to agricultural cropland as fertilizer, or bagged with other materials and marketed as “bio-solid compost” for use in agriculture and landscaping.

Chlorination is the process of treating the water with chlorine to kill the water-borne microbes that can possibly cause diarrhoea, typhoid, jaundice, amoebiasis etc. It is performed during the tertiary treatment step. Chlorine compounds like sodium hypochlorite are added to water to give effect to the process.

The sewage treatment unit employs the primary, secondary and tertiary treatment for the complete process. In the primary treatment, filtration of the large and solid waste is done. Then in secondary treatment, the decomposing microbes are used for the breakdown of the organic sewage. So, the secondary treatment is the biological treatment of the waste water. In the tertiary treatment, the chemical treatment is provided to the water.

Activated sludge treatment is the step involved in the treatment of sewage water. The sewage is treated in a large aerated tank and bacteria. Once, the process of decomposition is over, the filtrate obtained is called the activated sludge because it contains a high number of bacteria. This is then recycled in the next slot of treatment when the polluted sewage is available for the treatment. The activated sludge speeds up the process of decomposition by acting as an inoculum in the aeration tank. Primary treatment is the removal of large solid particles from the sewage. Tertiary treatment involves chemical treatment of the sewage water.