Fly Ash Enhancement Efficacy of Modified Anerobic Baffled Reaction (MABR) in Treatment of Low Strength Wastewater

In order to enhance the efficacy of modified anerobic baffled reaction (opposite folded plate anaerobic reaction) in low strength wastewater treatment, fly ash was mixed into inoculated anaerobic sludge. The results indicated that the start-up of all three test reactors run with fly ash enhancement was shortened markedly, and was completed after 50 days of operation. Average COD removal efficiencies of the 1^#, 2^# and 3^# reactors with different fly ash particle sizes (>83 mum, 20~83 mum and <20 mum) were 74.31%, 77.2% and 72.81%; average TP removal efficiencies were 32.87%, 34.07% and 30.92%; and specific methane production capacities were 2.21, 2.33 and 2.04 mL-g^-1-h^-1, respectively. The results of operation at short HRTs indicated that the optimal particle size of the fly ash was 20~83 mum. Based on the experimental results, the mechanism of fly ash enhancement of MABR efficacy and the reasons why fly ash particles of 20~83 mum obtained optimal efficacy are described.