Aerobic Treatment
From Swikipedia
Introduction
An aerobic treatment system or ATS, is a small scale sewage treatment system similar to a septic tank system, but which uses an aerobic process for digestion rather than just the anaerobic process used in septic systems. These systems are commonly found in rural areas where public sewers are not available, and may be used for a single residence or for a small group of homes.
Unlike the traditional septic system, the aerobic treatment system produces a high quality secondary effluent, which can be sterilized and used for surface irrigation. This allows much greater flexibility in the placement of the leach field, as well as cutting the required size of the leach field by as much as half.
Brief Description
Aerobic Treatment Plants are an effective sewage disposal system that breaks down the solid and aerate human and domestic wastes. The bacterial activity is promoted by aerobic bacteria (bacteria which survive in oxygenated environment) involving arrangements supplying oxygen to water. Oxygen is supplied in the form of air (diluted) to oxygenate water. The process of supplying air can be different viz. through fixed or floating aerators or through diffused aeration. Supply of oxygen aerates water for survival of bacteria that eat away the organic matter and clean up the water.
Advantages:
1) Minimum odor when properly loaded and maintained.
2) Large biochemical oxygen demand (BOD) removals providing a good quality effluent.
3) High rate treatment allowing smaller scale systems, e.g., less land required.
4) The final discharge may contain dissolved oxygen which reduces the immediate oxygen demand on receiving water.
5) The aerobic environment eliminates many pathogens present in agricultural wastes.
Disadvantages:
1) The main disadvantage of aerobic treatment is the energy cost of aeration at an adequate rate to maintain the dissolved oxygen levels needed to maintain aerobic conditions in the treated wastewater for aerobic growth.
2) Some organics cannot be efficiently decomposed aerobically. These biologically non-reactive components mainly composed of insoluble materials can account for up to 70% of the chemical oxygen demand (COD).
3) Another issue may rest with the fast production of biomass (sludge buildup) due to active aerobic growth powered by a sufficient oxygen supply by aeration, potentially leading to reduction in storage capacity of lagoons and/or ponds.
References:
http://en.wikipedia.org/wiki/Aerobic_treatment_system
http://www.wastewater-treatment-plants.com/aerobic-treatment-plant.html
