Comparative Technical Assessment of the Treatment Schemes for Faecal Sludge Handling and Management using Geotube and Jute Tube Technology

Abstract

Abstract Faecal sludge (FS) or septage collected from an onsite containment system such as septic tanks, pit latrines, bio-digester etc., is handled in sewage treatment facilities with the help of a co-treatment unit or tackled individually at faecal sludge treatment plants (FSTPs). Treatment of faecal sludge in FSTPs is a generally cumbersome, energy-intensive, and expensive process. Enhancing the size of the solid particle, dewatering, and disinfection are essential unit operations that contribute to a significant portion of the operational expenditure. Therefore, the present study took up the task of investigating and yielding a natural alternative to each of the above-delineated unit operations. Crushed seed powders of Moringa, Guilandina bonduc, Nirmali, Tamarind, Soap nut, Nutmeg, Jackfruit, and Custard apple seed powder experimented as natural coagulants. At the same time, a double-stitched cow dung-lined jute tube was utilized as the media for solid-liquid separation. Finally, Neem and Custard Apple seed and leaf powder were considered herbal disinfectants for the separated liquid and solid fractions, respectively. The findings of the physicochemical and biological analysis of the above unit operations were compared with a conventional polymer-based Geotube driven treatment scheme. The natural alternatives registered some promising outcomes. However, the combined treatment efficacy of 78.94% for pollutant removal and disinfection could not exceed the value of 99.01% offered by the conventional method. Moreover, herbal alternatives are scarce, expensive, and slow reacting. Therefore, the authors recommend further research to overcome the persisting issues with herbal alternatives for their field-scale adaptation.