The Removal Of Trace Pharmaceuticals During Coagulation Process And Its Influencing Factors

The Pharmaceutical Activity Compounds (PhACs) have gained much more attentions these days. In this study, five pharmaceuticals including acetaminophen (ACE), carbamazepine (CBZ),17β-Estradiol (E2), naproxen (NAP) and diclofenac (DCF) were selected as the target compounds to investigate their removal behaviours in Jar Test during coagulation.The deionize water and the tap water were selected as the source water. Kaolin and humic acids were spiked into the jar to simulate the suspended solid and the Natral Organic Matters (NOMs) respectively, and their influences on the removal of pharmaceuticals were studied. In addition, the adsorption removals by Powder Activited Carbon (PAC) for these compounds were also studied. The feasibility of the complex treatment "coagulation-PAC adsorption" for pharmaceuticals’removal was also evaluated.The experiment results indicated the poor removal of ACE and CBZ in deionized water by coagulation. The maximum removal percentages of them were both less than10%despite different dosage of aluninum sulfate. The best removal amoung these five compounds was DCF which has the largest logKow value, its maximum removal reached33%. Same poor removals of the pharmaceuticals were obtained in tap water, every compound was removed less than30%except E2.The influences of Kaolin on the removal on the removals of ACE and CBZ were not so obvious. Kaolin can enhance the removal of NAP, E2and DCF by coagulation, the best removals of them reached31.53%,36.46%and52.4%respectively. The single adsorption by Kaolin for these five compounds were less than20%. The humic acid can restrain the removal of E2, but can enhance the removal of acid compounds such as DCF and NAP. When humic acid and Kaolin were spiked into the source water at the same time, the same results were obtained for NAP and DCF. Their maximum removals reached63.5%and66.6%respectively. A good removal for these compounds was obtained after the addition of PAC into the jar during the coagulation process. More than80%of these compounds were removed by "PAC adsorption-coagulation" process indicated it is a feasibility way to remove the PhACs from the drinking water.