Field Survey on the Removal of Endocrine Disrupting Chemicals and Pharmaceutical Residues in Oxidation Ponds and Constructed Wetlands in Tropical Areas

Field surveys were conducted to obtain fundamental information on the removal of endocrine disrupting chemicals (EDCs) and pharmaceutical residues (PRs) with conventional water quality parameters in wastewater treatment plants (WWTPs) in Thailand. Oxidation ponds and constructed wetlands were focused on because these systems are adapted in about 60% of municipalities. In the field surveys, water samples including the influent and effluent as well as water at the middle part of plants were taken from 6 WWTPs receiving municipal sewage or hospital wastewater. Totally 11 EDCs and PRs which have been detected frequently in public water body in Thailand were measured by LC-MS/MS. It was found that the EDCs and PRs were present in the range of 0.001 to 102 μg/L and 0.001 to 1 μg/L in the influents and effluents of WWTPs, respectively. Every pollutant was removed by WWTPs in different manner. More than 80% of naproxen and 70% of estrone were removed, while those of other pollutants such as p-acetaminophen, ibuprofen, DEET, and gemfibrozil were different among WWTPs. It was shown that oxidation ponds and constructed wetlands are effective to remove EDCs and PRs concurrently. However, a further study will be needed to evaluate precise removal performances and relations to design and operation parameters.