Microbiological Quality of Biosolids

Faecal Sludge (FS) from on-site sanitation systems of many cities of developing countries is usually disposed of untreated mainly due to the lack of appropriate FS treatment options. Raw Sludge(Biosolids) is also associated with a potential health risk as a result of the pathogenic microorganisms in it. Some farmers engaged in Peri-urban agriculture spread the raw sludge on land as a conditioner and fertilizer. The study assessed the dewatering of faecal sludge mixed with different percentages of sawdust on an unplanted filter bed to produce Biosolids that can be applied as manure for agriculture use. The study also assessed how the sawdust added to the FS affected the microbial quality of Biosolids produced. The study revealed a constant reduction of pathogenic bacteria and helminth eggs in the Biosolids with increasing percentage of sawdust. The inactivation rate of the pathogens in the FS-sawdust treatment was highest in the highest percentage sawdust. This means that substantial benefits including reduction of potential health risk of the biosolids could be achieved to avoid posing a threat to public health and the environment.