Making biochar from human waste

Narsapuram municipality in West Godavari district holds the distinction of starting a Faecal Sludge Treatment Plant (FSTP) for the first time in the country to convert human excreta to biochar which could be used as manure in the fields.

The Bill and Melinda Gates Foundation funded the plant at a cost of `1.20 crore in the municipality which was started one year ago. 

Municipal chairperson Pasupuleti Ratnamala told The Hans India that the FSTP was established last year on the land donated by some philanthropists to build a park. “The municipality has already ensured that the citizens constructed quality toilets and mechanised removal of waste from septic tanks,” she said.

The septic tankers would bring the human waste to the FST Plant where it would be processed under Pyrolysis technology to convert it into biochar, she added. Apart from Narsapuram, Palakollu and Kovvuru were also selected in the district for establishing similar plants but due to a dearth of land the plants could not be established in the other two towns, Ratnamala said.

Pyrolysis is the thermal decomposition of materials at elevated temperatures in an inert atmosphere. The human waste is processed at a very high temperature separating water and human excreta. Ratnamala said that water is being used in the nearby park for the flower plants. However, biochar could be used as manure after mixing with red soil or black soil in the agriculture fields, she added.

Prof. Srinivas Chary, Director of Urban Governance at Administrative Staff College of India, explaining the pyrolysis technology to The Hans India, said that the septage is pasteurised to make the plant bio-safe even before the actual treatment process is carried out. “The separation of solid and liquid occurs after pasteurisation and solid is converted into biochar by drying and burning in a Pyrolyser,” he added. The water and biochar are safe for reuse without pathogens, he points out. 

The present practice of unsafe handling of faecal sludge in urban areas in the country is worse than open defecation in many ways and needs immediate attention, he avers.

After the initiative taken by municipal chairperson PasupuletiRatnamala and municipal commissioner Venkataramana, the town has surged ahead with total sanitation through safe management of faecal sludge containment, emptying of septic tanks, transportation, treatment and reuse, he said.

Ratnamala told The Hans India that many people collected the free samples of biochar which surely enriched the soil and increased agriculture production.