Department of Environmental Science, Baylor University, Waco, TX, United States.
Department of Environmental Science, Baylor University, Waco, TX, United States.
Water Res. 2023 May 15;235:119798. doi: 10.1016/j.watres.2023.119798. Epub 2023 Mar 2.
Parabens are commonly used preservatives that are weakly estrogenic. Wastewater effluent is the greatest contributor to the spread of parabens into rivers and other surface water. While previous studies indicate parabens are well removed in wastewater treatment by way of transformation, not much is known about the paraben transformation products. This study evaluates paraben transformation and release at two different wastewater treatment plants in Texas. Paraben concentrations were quantified for influent and effluent by season and by year at both treatment plants. Both seasonal and annual transformation rates were compared between the two wastewater treatment plants. Compounds were compared to evaluate differences in transformation rates and to determine if decreases in parent product concentrations are correlated to changes in transformation product concentrations. The study took place over one year and evaluated each season. Spring had higher influent concentrations and transformation rates at treatment plant 1, while summer had higher influent concentrations and transformation rates at treatment plant 2. PHBA was present in greatest amounts in influent and effluent at both sites with average yearly influent concentrations at 223.9 pM at plant 1 and 211.4 pM at plant 2. Transformation rates of parent parabens were greater at plant 1 with concentration of all three shorter chained parabens decreasing by over 50% after treatment. Formation of dichlorinated transformation products were greater at plant 1 with concentrations of ClMeP increasing by 1200% after treatment and ClEtP increasing by 940%. While shorter chained parabens generally had a greater transformation rate, no correlations were found between decreases in methyl and ethyl parabens and the formation of their respective dichlorinated transformation products.
对苯二甲酸酯是一种常用的弱雌激素性防腐剂。废水是对苯二甲酸酯扩散到河流和其他地表水的最大贡献者。尽管先前的研究表明，通过转化，对苯二甲酸酯在废水处理中可以很好地去除，但对其转化产物知之甚少。本研究评估了德克萨斯州两个不同污水处理厂的对苯二甲酸酯转化和释放情况。根据季节和年份，在两个处理厂的进水和出水处定量测定了对苯二甲酸酯浓度。比较了两个污水处理厂的季节性和年度转化率。比较了化合物，以评估转化率的差异，并确定母体产物浓度的降低是否与转化产物浓度的变化相关。该研究进行了一年，评估了每个季节。在处理厂 1，春季进水浓度和转化率较高，而在处理厂 2，夏季进水浓度和转化率较高。PHBA 在两个地点的进水和出水均以最大量存在，处理厂 1 的平均年进水浓度为 223.9 pM，处理厂 2 的平均年进水浓度为 211.4 pM。处理后，所有三种短链对苯二甲酸酯的浓度均降低了 50%以上，因此处理厂 1 的母体对苯二甲酸酯转化率更高。处理后，形成的二氯转化产物在处理厂 1 更多，ClMeP 的浓度增加了 1200%，ClEtP 的浓度增加了 940%。虽然短链对苯二甲酸酯的转化率普遍较高，但未发现甲基和乙基对苯二甲酸酯的减少与它们各自的二氯转化产物的形成之间存在相关性。
