Efficiency assessment of faecal sludge treatment plant (FSTP): An analytical study

The success of Swachh Bharat Mission (SBM) has increased the number of toilets in India. Treatment of septage and faecal sludge is now a big challenge to main the sanitation and hygiene in the society. Therefore, in the present study an attempt has been made to explore the concept and efficiency of Faecal Sludge Treatment (FSTP) technology. The paper also includes the study of characteristics of faecal sludge and biochar produced from faecal sludge. The efficiency of plant for biochemical oxygen demand (BOD), chemical oxygen demand (COD) and Total Suspended Solids (TSS) was observed 99.88%, 99.91% and 99.88, respectively. After the treatment all the studied parameters of treated water was found below the standards set by MOEF for FSTP discharge. After dewatering and drying, the faecal sludge is analyzed for calorific value, ash, fixed carbon, volatile matter, carbon, hydrogen, nitrogen, and sulphur. Calorific value of faecal sludge ranged from 3339.00 Kcal kg-1 to 3542.00 Kcal kg-1 with an average value of 3419.67 Kcal kg-1. Then the faecal sludge is pyrolysed to produce the energy and biochar. Biochar was analyzed for pH, colour, moisture, bulk density, potassium, nitrogen, phosphorus, lead, zinc, cadmium, copper, nickel, chromium, and mercury. All the parameters of biochar were found below the standard limits of Solid Waste Management Rules (SWM), 2016 except bulk density (2.07 g cm-3), potassium (1.02%), and nitrogen (3.09%). On the basis of biochar results, it may be concluded that the sludge produced can be used as manure in agriculture and gardening. Therefore, FSTP is a suitable, sustainable eco-friendly technology for the treatment of faecal sludge and also reduces the chances of soil and ground water pollution