ANAEROBIC TREATMENT OF SUGAR-MILL WASTE-WATER IN DOWNFLOW FIXED-BED REACTORS

Preliminary experiments to evaluate the behaviour of anaerobic fixed-b ed reactors treating sugar-mill wastewater were carried out Four hydra ulic retention times (0.5, 1.0, 2.0 and 4.0 days) at three levels of s trength (raw wastewater, diluted 1:1 and diluted 1:2) were tested. Thr ee glass columns of 1 m height and 6 litres total volume, packed with gravel of 3 cm average particle size, and bed porosity of 0.53 were em ployed It was found that organic matter removal increased with the hyd raulic retention time and decreased with the influent concentration an d such reactors might be used for treatment of sugar-mill wastewaters.