Heavy metals and microbial loads in raw fecal sludge from low income areas of Ashanti Region of Ghana

Abstract

This study was carried out to determine the heavy metals and microbial loads of raw public toilet sludge from low income areas (peri-urban and rural) of Ashanti Region of Ghana. Fecal sludges were sampled from public toilets. Methods outlined in Standard Methods for the Examination of Water and Wastewaters were used for the analyses of fecal sludge samples. Range of heavy metals concentrations were found as 0.039–5.216 mg/l and 0.010–1.488 mg/l for peri-urban and rural areas, respectively. These concentrations were in the order of Mn > >Cu > >Fe > >Zn > >Pb > >Ar > >Cd and Zn > >Mn > >Fe > >Cu > >Pb > >Ar > >Cd for peri-urban and rural areas, respectively. The range of bacteria loads was measured as 1.4 × 106–4.5 × 107CFU/100 ml for peri-urban and 0.2 × 106–4.5 × 107CFU/100 ml for rural areas. Similarly, range of helminths was determined as 1–18 eggs/100 ml for both peri-urban and rural areas. The study showed that the levels of heavy metals and microbial quantities were generally higher in peri-urban compared to rural areas. However, fecal sludge from these low income areas are not recommended for direct use in agriculture unless they are given further treatment. Composting is recommended as a promising and suitable method for effective treatment of fecal sludge resulting in a hygienically safe and economically profitable product.