Batch Anaerobic Co-digestion of Agro-industrial Wastewater Produced in the Upper Litani Basin Lebanon

Abstract

The Litani River in Lebanon is subjected to many pollution sources originating from the agro-industries including dairy farms and slaughterhouses. This pollution is leading to a severe degradation in water quality. The aim of this research is to mitigate pollution resulting from the discharge of wastewaters originating from dairy farm and poultry slaughter house industries. The study included characterization of wastewaters samples collected from the upper Litani basin followed by mono-digestion and co-digestion experiments. The digested samples included cheese whey wastewater (CWW) and poultry slaughterhouse wastewater (PSW). The study was conducted in 5-L lab-scale anaerobic digesters at an organic loading rate of 1.1 g.COD/L.day for 58 days. Treatment combinations included CWW (R1), PSW (R2), 75:25 CWW:PSW (R3), 25:75 CWW:PSW (R4), and 50:50 CWW:PSW (R5). The test results indicated that R4 with 25:75 CWW:PSW combination yielded the best treatment outcome. A kinetic assessment was conducted for the five reactors to evaluate the disgestion kinetic parameters and lag time. The study showed that the logistic function model yielded the best fit for the cumulative methane data.