Phosphorus Removal through Phosphate Bio-Reduction of an Anaerobic Sequencing Batch Reactor in Treating Preserved Pickle Wastewater

Biological phosphate reduction was observed in the authors´ previous studies in an anaerobic sequencing batch reactor (ASBBR) in treating preserved pickle wastewater with high salinity and phosphorus concentration. Key factors such as temperature, pH value, organic loading and influent nitrate concentration that influence this process in terms of phosphorus removal efficiency are investigated in this paper. The results show that these factors can take effects on phosphorus removal efficiency through phosphate reduction. Under the condition of 30degC, pH value 7.1 and organic loading rate 1.0 kgCOD/(m³ldrd), the removal rates for organics (expressed as COD) and phosphate can be 73.35% and 39.85% respectively. The suitable range of is found at 105~160 mg/L, too high or too low nitrate concentration are neither inhibitive biological phosphate reduction.