Sheekha, Madhusoodanan M.S., D.S. Gurjar, Vartika Singh, Gouthami B., Soujanya B. and Nitin Kumar
Abstract
This study investigates the characterization in terms of physical, chemical, and biological properties of biochar derived from faecal sludge, aiming to evaluate its potential for agricultural and environmental applications. Faecal sludge samples were collected from a household septic pit at Kotla Nihang, a census town in Rupnagar district of Punjab, during the financial years of 2020-21 and 2021-22. Biochar samples were produced at pyrolysis temperatures of 300 °C, 400 °C, and 500 °C with residence times of 30, 60, and 90 minutes in an oxygen-free environment. Physical analysis revealed that increasing pyrolysis temperature enhanced favorable physical properties; including ash content, BET surface area, and water holding capacity, while reducing moisture content and volatile matter, which are crucial for enhancing soil aeration and water retention. Chemical analysis revealed that higher pyrolysis temperatures increased the concentrations of pH, electrical conductivity, whereas total nitrogen and total organic carbon contents decreased. Low pyrolysis temperatures (300 °C) produced acidic biochar, whereas higher temperatures (400 °C and 500 °C) yielded biochar with alkaline characteristics. This finding is significant for agricultural applications, as biochars produced at higher temperatures can neutralize acidic soils and improve fertility, while those produced at lower temperatures can address alkalinity issues in soils. The biological assessment confirmed the absence of faecal coliform bacteria in the biochar, ensuring its safety for soil amendment use. Overall, faecal sludge-based biochar demonstrates promising potential for enhancing soil quality/soil health and promoting sustainable agricultural practice.