Concentrations of PCBs and heavy metals in water of the dam reservoir and use of pre-hydrolyzed coagulants to micropollutants removal from surface water

摘要

The aim of the presented research work was to analyze the pollution in the Kozlowa Gora Dam Reservoir (Poland) with indicative Polychlorinated biphenyls (PCBs) (28, 52, 101, 118, 138, 153, 180) and heavy metals (Zn, Cu, Ni, Cd, Pb, Cr). Aluminum sulfate and pre-hydrolyzed polyaluminium chloride (PAX-XL1, PAX-XL19) were used as coagulants, and the following parameters were analyzed in the water samples from the Kozlowa Gora Dam Reservoir: turbidity, color, and concentrations of PCBs and heavy metals (Ni, Cd, Pb). The concentrations of Zn, Cu, Ni, Cd, Pb, and Cr in the water were as follows: 0.022; 0.012; 0.015; 0.01; 0.014; <0.01mgL~(-1). The total concentration of PCBs in the water amounted to 6.0ngL~(-1). The highest concentration was shown for PCB 28 (1.6ngL~(-1)), while the lowest concentration was shown for PCB 180 (0.5 ngL~(-1)). After the application of PAX19, polyalu-minum chloride with the highest alkalinity, the best results (among the investigated coagulants) for the chosen contaminants' removal were obtained; 98% decrease of turbidity and 86% lead concentration were acquired. The highest removal rates for the indicator PCBs were obtained using aluminum sulfate. The total concentration of PCBs was reduced by 71%. The removal efficiency for particular congeners ranged from 57% (PCB 28) to 90% (PCB 153).