Green Bio-compost and Animal Farming for Faecal sludge treatment

Location: Bansberia, West Bengal
Scale: City level
Implementing organisation: Greenery bio-compost and Animal Farming in collaboration with Bansberia Municipality

Design capacity: 1500 MT/year
Running capacity: 400 MT/year (0.4 cum)
Operational since: 2006
Opex:

This is a joint venture project of Bansberia Municipality with Greenery bio compost and Animal Study Pvt. Ltd. The local body provided land for construction and operation of the facility in year 2006. Spread to an area of 2.75 hectares, the treatment system functions on natural treatment system which treats and converts faecal sludge and septage into compost along with vermicomposting, mixing of lime water, poultry waste, husk, leather ash etc. This treatment system has an established revenue model where the end product is sold to farmers based on quality of compost at an approx. rate of Rs. 17 per kg.

The technology chosen for the treatment of faecal sludge and septage is sludge drying beds under sunlight. Step wise process is explained below:

Step 1: The faecal sludge is dried in drying beds for 2-3 weeks until most of the water evaporates. In order to increase the Nitrogen content, lime water and poultry excreta is mixed to kill the pathogens and to increase the rate of composting. It takes another 3 weeks to dry this sludge. Once dried, it is stored in for 2 weeks.

Step 2: This dried sludge is then spread out and kept in open for a year exposed to rainfall. Due to its high Nitrogen content, it becomes suitable for plant growth which helps in maintaining the pH of the sludge around 6.5 -7.

Step 3: A three layer compost is prepared to form one half of the bio compost. The dried sludge forms the first layer. Leather ash (from the boiling of slaughter house wastes) rich in Nitrogen and Potassium forms the next layer on top of this. Kheri (animal blood from slaughter house, coconut peel mixed with husk and forms Kheri) forms the third layer on top of the leather ash. This layer is rich in Iron and Calcium.

Step 4: Vermi composting of organic waste from households is mixed with the faecal compost. The final product is collected after sieving. In order to enhance the quality of the bio-compost, Neem seed powder is also added as per the need.

Advantage

The Bansberia municipality makes sure that the FS emptied is transported to the treatment facility. The municipality do not levy any charge for discharging of FS at plant. The municipality solid waste is also dumped next to this facility, and this method also addresses the challenges of disposal of slaughter house waste. The product is fetching good price in the market making the system economically viable.

Since the technology used for treatment is only sun drying, there is possibility of leachate of the effluent. This could lead to ground water as well as surface water contamination as the facility is functioning right on the banks on river Hoogly.

Mr Subrodeep Dutta,
Director, Greenery Bio Compost and Animal Farming
 M: 09804831644