Abstract
The study aims to treat chocolaterie wastewater by combining the primary anaerobic treatment and solar photo-Fenton process. A laboratory scale anaerobic treatment was conducted in a hybrid up-flow anaerobic sludge blanket reactor at organic loading rates (OLRs) ranging from 0.413 to 18.2 kg COD/m(3)/d over a period of 320 d. The optimum OLR of the anaerobic reactor was found to be 16.5 kg COD/m(3)/d, and the corresponding chemical and biochemical oxygen demand (COD and BOD, respectively) removal at this OLR were 88% and 91%, respectively. A maximum biogas production of 30 mL/d was achieved. The effluent from the anaerobic treatment was further treated through the solar photo-Fenton process. At the optimised conditions, photo-Fenton treatment achieved COD and BOD removals of 83% and 85.4%, respectively. The predicted optimum parameters for the solar photo-Fenton process were 0.25 g/L of Fenton, 0.85 g/L of H2O2, and 30 min of solar exposure. Combining solar photo-Fenton with primary anaerobic treatment resulted in a COD removal of 96%, which completed the wastewater treatment.