Modeling Soluble and Particulate Lead Release into Drinking Water from Full and Partially Replaced Lead Service Lines
Modeling Soluble and Particulate Lead Release into Drinking Water from Full and Partially Replaced Lead Service Lines
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DOI：
10.1021/acs.est.6b04994
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发表时间：
2017-03-21
影响因子：
11.4
通讯作者：
Biswas, Pratim
中科院分区：
文献类型：
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作者：
Abokifa, Ahmed A.;Biswas, Pratim
部分更换铅管线，由于管道结垢和电偶腐蚀的干扰，往往导致铅微粒长期过量释放。在本研究中，建立了一种模拟完全和部分替换的LSLs中颗粒和溶解铅的释放和运输的建模方法。将传质模型与随机居民需水量发生器相结合，研究了正常家庭用水流量模式对铅暴露的影响。该模型通过将模拟结果与中试装置的实验测量结果进行比较来校准，中试装置报告了不同流速和水化学情景下的铅释放情况。在蒙特卡罗模拟框架中应用该模型，预测部分替换LSL会导致释放具有高浓度颗粒铅的峰值（1011.9 +/- 290.3 μ g/L），比模拟的完全LSL释放的浓度高5倍。敏感性分析表明，流动需求强度显著影响颗粒铅释放，而溶解铅水平更依赖于停滞期的长度。研究发现，在管制取样前预先冲洗低浓度污水，若以低流速取样(
Partial replacement of lead service lines (LSLs) often results in the excessive long-term release of lead particulates due to the disturbance of pipe scale and galvanic corrosion. In this study, a modeling approach to simulate the release and transport of particulate and dissolved lead from full and partially replaced LSLs is developed. A mass-transfer model is coupled with a stochastic residential water demand generator to investigate the effect of normal household usage flow patterns on lead exposure. The model is calibrated by comparing simulation results against experimental measurements from pilot-scale setups where lead release under different flow rates and water chemistry scenarios was reported. Applying the model within a Monte Carlo simulation framework, partial replacement of the LSL was predicted to result in releasing spikes with significantly high concentrations of particulate lead (1011.9 +/- 290.3 mu g/L) that were five times higher than those released from the simulated full LSL. Sensitivity analysis revealed that the intensity of flow demands significantly affects particulate lead release, while dissolved lead levels are more dependent on the lengths of the stagnation periods. Preflushing of the LSL prior to regulatory sampling was found to underestimate the maximum monthly exposure to dissolved lead by 19%, while sampling at low flow rates (