Physico-chemical Characterization of the Leachate from Fermentation Composts Treated with Lime and Soda: Case of the Composting Platform in Aného, Togo

This study aims to determine the parameters measuring the reduction rate of the organic matter during fermentation and its bio-availability after maturation of the compost made using fermentable fractions of household waste. Thus, a physico-chemical characterization of the raw leachate and the leachate treated with lime and caustic soda was carried out. The results showed that, the contents of the other parameters measured are higher for the raw leachate compared to those obtained for the treated leachate. Organic and inorganic pollution is reflected by high Chemical Oxygen Demand (COD), absorbance at 254 nm, turbidity and suspended matter. The COD values ​​in the raw leachate vary between 13000 and 19150 mg/O2/L; those of the absorbance at 254 nm between 30.5 and 34.15 OD; those of turbidity between 156 and 255 NTU (Nephelometric Turbidity Unit) and those of suspended matter between 48 and 1600 mg/L. In the treated leachate, the COD values ​​oscillate between 4489 and 8743 mg/O2/L; those of the absorbance at 254 nm between 6.69 and 31.1 OD; those of turbidity between 57.8 and 122 NTU and those of suspended matter between 70 and 92 mg. These results reflect a good reduction after treatment with lime and soda.