School of Environmental Science and Engineering, Tianjin University, 135 Yaguan Road, Jinnan District, Tianjin, 300350, China; Renai College, Tianjin University, Jinghai District, Tianjin, 301636, China.
School of Environmental Science and Engineering, Tianjin University, 135 Yaguan Road, Jinnan District, Tianjin, 300350, China.
Chemosphere. 2021 Jan;262:127904. doi: 10.1016/j.chemosphere.2020.127904. Epub 2020 Aug 6.
Manganese accumulated in corrosion scales on drinking water distribution systems (DWDSs) can be released into bulk water, causing discolouration and thereby leading to customer concerns about drinking water quality. A static release experiment was conducted on iron pipe scales under three different temperatures, pH values, alkalinity values, sulfate (SO) concentrations, and disinfectants to study the separate effect of these factors on Mn release from pipe scales under stagnant conditions. Results showed that more Mn was released from corrosion scales under the conditions of lower pH, lower alkalinity, higher temperature, and higher SO concentrations. Three commonly used disinfectants, sodium hypochlorite (NaClO), chlorine dioxide (ClO), and monochloramine (NHCl) were found to inhibit the release of Mn from iron corrosion scales, with the ranked order of inhibitory effect of ClO≈NaClO > NHCl under the same CT (product of disinfectant concentration and contact time) value. The orthogonal experimental results indicated that SO and alkalinity had extremely significant effects on the release of Mn from pipe scales, while pH and disinfectant type had a significant impact on the release of Mn from pipe scales. Thus, the SO concentration and alkalinity of the bulk water should be determined to avoid excessive release of Mn into drinking water. However, further investigation of the effect of disinfectants on Mn release in DWDSs is necessary. This research helps establish a systematic understanding of the influential factors in Mn release from pipe scales into bulk water, as well as their significant relationships.
在饮用水分配系统（DWDS）的腐蚀层中积累的锰可以释放到主体水中，导致变色，从而引起客户对饮用水质量的担忧。本研究采用静态释放实验，在三种不同的温度、pH 值、碱度值、硫酸盐（SO）浓度和消毒剂条件下，研究这些因素单独对铁管垢中 Mn 释放的影响。结果表明，在较低 pH 值、较低碱度值、较高温度和较高 SO 浓度条件下，腐蚀层中释放出更多的 Mn。三种常用的消毒剂，次氯酸钠（NaClO）、二氧化氯（ClO）和一氯胺（NHCl），被发现可以抑制铁腐蚀层中 Mn 的释放，在相同的 CT（消毒剂浓度和接触时间的乘积）值下，ClO≈NaClO＞NHCl 的抑制效果顺序。正交实验结果表明，SO 和碱度对 Mn 从管道垢中的释放有极显著影响，而 pH 和消毒剂类型对 Mn 从管道垢中的释放有显著影响。因此，应确定主体水中的 SO 浓度和碱度，以避免 Mn 过度释放到饮用水中。然而，有必要进一步研究消毒剂对 DWDS 中 Mn 释放的影响。该研究有助于系统地了解 Mn 从管道垢中释放到主体水中的影响因素及其显著关系。
