Zhang Yuanyuan, Lin Yi-Pin
Department of Civil and Environmental Engineering, Faculty of Engineering, National University of Singapore, Singapore, 117576, Singapore.
Environ Sci Pollut Res Int. 2015 Jun;22(11):8405-11. doi: 10.1007/s11356-014-3999-9. Epub 2014 Dec 25.
Unplasticized polyvinyl chloride (uPVC) pipes have been used in the premise plumbing system due to their high strength, long-term durability, and low cost. uPVC pipes, however, may contain lead due to the use of lead compounds as the stabilizer during the manufacturing process. The release of lead from three locally purchased uPVC pipes was investigated in this study. The effects of various water quality parameters including pH value, temperature, and type of disinfectant on the rate of lead release were examined. The elemental mapping obtained using scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDX) confirmed the presence of lead on the inner surfaces of the uPVC pipes and their surface lead weight percentages were determined. The leachable lead concentration for each pipe was determined using high strength acidic EDTA solutions (pH 4, EDTA = 100 mg/L). Lead leaching experiments using tap water and reconstituted tape water under static conditions showed that the rate of lead release increased with the decreasing pH value and increasing temperature. In the presence of monochloramine, lead release was faster than that in the presence of free chlorine.
未增塑聚氯乙烯（uPVC）管因其高强度、长期耐用性和低成本而被用于室内给排水系统。然而，由于在制造过程中使用铅化合物作为稳定剂，uPVC管可能含有铅。本研究调查了三种本地购买的uPVC管中铅的释放情况。研究了包括pH值、温度和消毒剂类型在内的各种水质参数对铅释放速率的影响。使用扫描电子显微镜-能量色散X射线光谱仪（SEM-EDX）获得的元素映射证实了uPVC管内表面存在铅，并测定了其表面铅的重量百分比。使用高强度酸性EDTA溶液（pH 4，EDTA = 100 mg/L）测定了每根管道的可浸出铅浓度。在静态条件下使用自来水和配制水进行的铅浸出实验表明，铅释放速率随pH值降低和温度升高而增加。在一氯胺存在的情况下，铅的释放比在游离氯存在的情况下更快。
