Study on Production of an Auxiliary Agent of Coagulation Using Waste Polystyrene Foam and Its Application to Remove Phenol from Coking Plant Effluent

摘要

Waste of polystyrene foam was converted into an anion auxiliary agent of coagulation and was used for the removal of phenol from coking plant effluent. Waste of polystyrene foam was crushed into small pieces and immersed into a solution of 98% sulfuric acid to attach sulfonic groups to polymer chain, which were responsible for the exchange properties of the modified plastic into a water-soluble polymer, polystyrene sulfate (PSS). The anion auxiliary agent of coagulation capacity was determined. The influences of pH, sedimentation time, and concentration of PSS on the treatment of phenol effluent from coking plant were studied in this article. Polyaluminum chloride (PAC) and PSS were used as flocculants. The flocculation performance increased significantly with the concentration of PSS. When PSS in effluent increased from 5 to 20 mg/L, the removal rate of phenol increased from 27 to 96% by treating with PAC of 20 mg/L at 25℃, while the removal rate decreased from 96 to 86% when the PSS concentration was 60 mg/L. Although the flocculation effect of PAC was excellent, the floc was abundant, small, loose, and unstable, while PSS was less abundant and more stable.