Physicochemical and Bacteriological Properties of Sludges of Airport Zone Wastewater Plant and Attempts of Their Valorization as a Coal for Cooking

The national sanitation program aims to collect and effectively treat wastewater using high-value wastewater treatment plants (WWTPs). The Casablanca region, with a population of 4 million, discharges more than 350,000 m3 of wastewater into the sanitary network. Only 100,000 m3 pass through the wastewater treatment plants installed in the peri-urban area. The cities of Casablanca and Mohammedia use an outlet that discharges 250,000 m3 into the Atlantic Ocean without any advanced treatment. Wastewater treatment generates several by-products, mainly sludge. At a time when landfill admission conditions are becoming stricter, the quantities of urban and industrial sewage sludge are constantly increasing. The bioconversion of biological sewage sludge into value-added products is considered as an ecological and economical approach for the management of this type of waste. To this end, this study focuses on the physicochemical and bacteriological characterization of the sludge from the wastewater treatment plant. The interests of the follow-up are temperature, pH, conductivity, COD, BOD5, NH4+, NO3-, NKT, PO43-, heavy metals (Pb, Zn), total germs, fecal coliforms, fecal streptococci, and helminth eggs. The physicochemical and bacteriological analysis of samples taken during the second half of the year 2021 showed that at the station of Mediouna, the rate of abatement recorded reached 90.9% for COD, 99.25% for BOD5, 99.13% for TSS, 95.59% for total Kjeldahl nitrogen, and 80.20% for orthophosphate. For the airport area. At the same time, the level of physicochemical quality (pH, conductivity and heavy metals) and the hygienic quality of the treatment plant are in accordance with WHO and FAO standard and showed that the sludge of the sewage treatment plant can be valorized as a coal.