The article presents the reports the performance of municipal waste-water treatment plant using laterite soil-based constructed soil filter (CSF) system. The plant was monitored over a period of 17 months and the result is presented. The dissolved oxygen levels were increased along with the chemical oxygen demand (COD). The bio-chemical oxygen demand (BOD) reduced was significantly reduced. The features of the system are:
lowHRT, high,hydraulic loading, no chemicals, pretreatment and mechanical aeration, odor free, lowenergy requirement.

CSF system
The CSF system is developed by IIT Bombay. It provides an environment where the natural processes like respiration, mineral-weathering and photosynthesis are responsible for bio-conversion .The native micro-flora, geophagus
worm Pheretima elongata, and bio-indicator plants containing culture is used as the primary component. The major processes going on are bacterial processing of organics and oxidizable inorganics. The natural oxygen supply is behind this. The oxic potential and near neutral pH reduces the pathogens.

Plant description
The water treatment plant under study is located in Mumbai. unclassified, untreated raw sewage is received by the plant. The output water from the plant is used for is used for irrigation in nearby gardens and lawns and in proximity a large urban population lives.

operation
batch as well continuous mode of the project is available. waste-water is pumped and applied on to the top surface of the CSF. The incoming water first percolates through the trenches and gets collected in the collection tank. with the help of distribution system, it is then pumped onto the media. Finally the collection tank recieves the filtered water which is then recirculated.

Get the report here:
http://dspace.library.iitb.acjspui/bitst...1/6006.pdf