Dewatering as a primary treatment of faecal sludge in individual residential sector (a technologies review)

Abstract

Dewatering of faecal sludge (FS) is the most efficient method of pretreatment of bioorganic human waste for minimizing the faecal sludge volume. This process may be considered as one of management tool in service chain of Faecal Sludge Management (FSM). For this purpose technological features of methods, the advantages, disadvantages and possibilities of the use have been analysed. The article provides a review of the most efficiently methods of faecal sludge dewatering generated in the individual residential sector (unplanted drying beds, planted drying beds, solar drying, mechanical dewatering, geotubes) and their analysis in order to select the best available technology in accordance with the selection criteria. We used the analytic hierarchy process to determine the most multi-operated and effective processing method of faecal sludge dewatering. The final ranking for each dewatering technology was based on the global weights of 10 criteria (dewatering efficiency, operation time, process automation, required space, climate dependent, capital expenditures, operating costs, energy efficiency and environmental impact). The results identify dewatering method with the highest priority result based on priority eigenvalues of criteria.