Pollution Characteristics and Enhanced Removal of Organic Phosphorus in Effluent from a Wastewater Treatment Plant

Abstract

Given the presence of organic phosphorus (OP) pollution in wastewater treatment plant (WWTP) effluents, contaminant properties and enhanced removal approaches were investigated. The experimental results showed that the respective levels of effluent total phosphorus (TP), PO43--P, Poly-P, and OP were 0.62, 0.22, 0.03, and 0.37 mg·L-1, respectively, for which the ratio of OP reached up to 59.7%. Based on the flow analysis, the proportions of influent PO43--P, Poly-P, and OP changed from 54.4%, 6.3%, and 39.3% to 16.9%, 14.5%, and 68.6% within the effluent. The OP content was positively correlated with the DOC content (R2=0.65), and the average contents of hydrophilic and hydrophobic OP were 0.12 mg·L-1 and 0.31 mg·L-1, respectively. C/P in hydrophobic OP was relatively lower than that in hydrophilic OP, which indicated that the bioavailability of hydrophobic OP was higher. However, the bioavailability of hydrophobic OP was only 20%, which implied that the effluent OP basically consisted of refractory components. A total of 32.6% of OP within the effluent was removed through bioadsorption reactions with activated coke, while the removal of OP was up to 79.1% when 30 mg·L-1 of O3 was applied, which suggested that advanced oxidation was more beneficial for the enhancement of OP removal.