Utilization of Feacal Sludge Waste for Co-composting Process with Partially Digested Biosolids

Abstract

Sustainable waste management strategies are becoming increasingly important due to the need to conserve natural resources and recycle the waste materials. Co-composting of feacal sludge (FS) is considered as an inexpensive and appropriate technology to develop sanitation and waste management in low-revenue countries, especially in urban areas where a complete treatment of large volume of sludge is often lacking. In this present study, biosolids from the treatment plant from a residential engineering college campus were utilized for co-composting along with other in-house refuse materials as additives. Dewatered sludge and other refuse materials like leaves, paper, cartons, grass clippings, sawdust and vegetable waste were collected from the same premises; uniformly aerated bins were equipped with the same. Physicochemical parameters of samples such as pH, EC, TOC/TN, NH4–N and NO3–N were performed in the laboratory. Intermittent spraying of sludge was able to maintain moisture content below 70% in the bins throughout the composting process. It was observed that NO3–N content was increasing during the first three weeks and decreased from 4th week of the composting. Additionally, C/N ratio and NO3–N were increased with increasing time period of the compost sample. However, the maturity of compost was confirmed based on the stability of the final composition. From the results, it can be concluded that the co-composting of feacal sludge with biosolids constituted a competent process for recycling and also obtained organic manure with a good degree of stability and maturity for agricultural practices.