HYGIENE CONCERNS, RESOURCE RECOVERY AND USE POTENTIAL OF FAECAL SLUDGE FROM ONSITE SANITATION FACILITIES IN DAR ES SALAAM

Abstract

Inadequate faecal sludge management in most of developing countries results in the disposal of faecal sludge in a hazardous manner. This poses public health and environmental risks. On the other hand, faecal sludge can be recovered and reused for different applications. This paper reports on the findings related to resource recovery and re-use potentials of faecal sludge from onsite sanitation facilities in Dar es Salaam City. A total of 120 faecal sludge samples from various onsite sanitation systems were collected from the vacuum tanks that brought the sludge for disposal at Vingunguti Waste Stabilisation Ponds. Physicochemical and biological characteristics of faecal sludge were analysed in the laboratory. Also, 425 questionnaires were administered in eight wards to determine the existing faecal sludge management practices.. Results shows that faecal sludge is contaminated with heavy metals including copper, lead, cadmium, zinc and chromium with concentrations of 2.053±0.016, 15.534±0.102, 0.704±0.006, 4.392±0.064 and 3.133±0.117 mg/kg, respectively. Additionally, faecal sludge contained helminths pathogenic organisms ranging from 2 to 105 eggs/L of hookworm and Ascaris lumbricoides. These results indicate that faecal sludge is potentially hazardous if protective gears are not used in its handling. A model to determine the potential for resource recovery revealed that faecal sludge can be recovered for use as soil conditioner and aa a source of energy. 

Keywords: Faecal sludge, Resource recovery, Onsite sanitation, heavy metals, helminths