| 基于紫外光谱分析的腐殖质混凝控制 |
| 摘要点击 2120 全文点击 598 投稿时间：2018-01-19 修订日期：2018-04-04 |
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| 中文关键词 腐殖酸 混凝 紫外光谱 尺寸排阻色谱 组分 在线控制 |
| 英文关键词 humic acid coagulation ultraviolet spectrum size exclusion chromatography (SEC) fraction online control |
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| 中文摘要 |
| 腐殖质是水溶性天然有机物（DOM）的主要成分，对水处理过程有重要影响.为探究利用紫外光谱分析实现饮用水处理在线混凝控制的可行性和理论基础，以含腐殖酸和高岭土配水为实验对象，通过烧杯实验考察了不同水质条件对PACl混凝剂最佳投加量的影响，研究了SUVA254和光谱特征斜率与混凝效果的相关性，利用排阻色谱分析了紫外光谱斜率与水体有机物组分之间的关系.结果表明，混凝剂最佳投加量与DOM浓度呈正比关系，两者计量学关系（以Al/DOC计）为0.61 mg·mg-1.随混凝剂投加量的增加，腐殖酸溶液的SUVA254从8.9 L·（mg·m）-1下降并稳定至2.0 L·（mg·m）-1，有机物去除率与SUVA254值呈正相关.光谱斜率与SUVA254的变化趋势一致，且S275~295与SUVA254线性相关最优（R2=0.81）.排阻色谱结果表明，混凝优先去除DOM中的腐殖质组分，S275~295与有机物中腐殖质组分对总UVA254的占比存在明显的线性相关，光谱斜率测定对实现饮用水混凝过程的控制有重要意义. |
| 英文摘要 |
| Humic substance (HS) is a main component of dissolved organic matter in the aquatic environment and significantly affects water treatment processes. To investigate the applicability and principle of UV spectrum analysis for coagulation control, laboratory jar tests were conducted with synthetic waters that had varying concentrations of HS and kaolinite. Thus, the influence of water quality conditions on the optimal coagulant dose (OCD) was determined and further correlated to Specific Ultraviolet Absorbance (SUVA254) and the ultraviolet spectral slopes of the coagulated water. Subsequently, the relationship between the UV spectral slopes and organic fractionation was further identified by using size exclusion chromatography (SEC). The results showed that the coagulant demands of the synthetic waters were positively related to dissolved organic carbon (DOC). Consequently, a stoichiometric relationship (0.61 mg·mg-1 calculated as Al/DOC) was found between the coagulant demand and initial DOC of the synthetic water. As the coagulant dose increased, SUVA254 decreased from 8.9 L·(mg·m)-1 to a steady level of 2.0 L·(mg·m)-1 and the removal efficiency of DOC was positively correlated with SUVA254. Spectral slopes in different wavelength ranges had showed similar tendencies, with S275-295 having the best correlation with SUVA254 (R2=0.81). Furthermore, SEC results demonstrated that coagulation preferentially removed humic substances, leading to reduced humification. As a result, S275-295 had the highest correlation with the portion of UVA254 contributed by humic substances in water. Therefore, online measurement of ultraviolet spectral slopes was an important aspect in the control of coagulant dosing. |
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