Investigation of biological phosphorous removal for the treatment of a cellulose acetate manufacturing wastewater

Abstract

The use of a two Stage Biological Phosphorus Removal (BPR) system to treat a high strength, low pH industrial wastewater was evaluated. A laboratory scale BPR system was continuously operated and fed the industrial wastewater. Effective utilization or removal of carbonaceous material as measured by Chemical Oxygen Demand (COD) was attained, but BPR was not achieved. Other advantages of BPR and its anaerobic-aerobic sequencing were also monitored. While the loading on the aerobic zone was reduced 10 to 20% by the anaerobic zone, there was no noticeable improvement in secondary settling or effluent quality.

Efforts to supplement the industrial wastewater influent with phosphorus, nitrogen, potassium and iron did not produce any significant improvements. Mixtures of the industrial wastewater, municipal wastewater, and supplements were also used as influent to the system. This indicated that the laboratory BPR system was capable of BPR when provided with an appropriate influent.

Information characterizing the influent and system operation were collected. Loading and operating parameters were computed with these data. When compared with phosphorus removal data, little was revealed and the results varied. The information did indicate that pH was an important factor in achieving BPR. The industrial wastewater pH of 4.4 to 4.8 resulted in a pH of 5.5 in the anaerobic zone, and this prevented the establishment of BPR.