| 蛋白类有机质在水厂各处理单元中的去除特性 |
| 摘要点击 1915 全文点击 656 投稿时间：2020-10-27 修订日期：2020-12-14 |
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| 中文关键词 蛋白类有机质(pDOM) 高效尺寸排阻色谱 饮用水处理 混凝 活性炭吸附 |
| 英文关键词 protein-like dissolved organic matter (pDOM) high performance size exclusion chromatography drinking water treatment process coagulation activated carbon adsorption |
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| 中文摘要 |
| 蛋白类有机质（pDOM）广泛存在于天然水体中，是非常重要的含氮消毒副产物前驱物.近年来，其在饮用水处理过程中的去除和控制逐渐受到广泛关注.本文以两个实际饮用水厂不同工段进出水为研究对象，通过高效尺寸排阻色谱联合紫外、荧光及有机碳检测器的分析方法，对水样中pDOM不同分子量组分的去除特性及变化规律进行探究.同时，选取混凝和活性炭吸附两种水处理技术进行小试实验，进一步探究pDOM组分在常规处理单元的去除规律.结果表明，pDOM在不同水处理单元具有不同的去除特性，预氧化能够有效分解类色氨酸和类酪氨酸型高分子组分，且随着氧化剂氧化作用增强，更多的高分子组分被氧化分解为小分子，但一些分子量较大的脂肪族蛋白等组分则难以被氧化分解；混凝沉淀对高分子组分有良好去除效果，尤其是类色氨酸型pDOM，且混凝过程可能存在一定量pDOM组分的释放，多为小分子及疏水性组分；活性炭过滤易去除分子量较低及疏水性较强的组分，但炭砂滤池长期运行可能存在微生物滋生，因此造成出水部分pDOM组分浓度增加；紫外消毒在一定程度上提高了小分子组分的去除效率.由于实际水厂运行过程中水质条件变化复杂且微生物活动不可控，故各处理单元对pDOM的去除并没有展现协同作用.且相比于腐殖质类物质，pDOM组分受水质变化影响较大，从整体工艺流程来看，去除效果有限.因此在水厂未来运行中，应加强进出水中pDOM各组分的监测，及时对各处理单元运行参数进行调整，同时考虑结合臭氧-生物活性炭工艺，或增加纳滤等膜过滤单元，严格控制pDOM组分的去除. |
| 英文摘要 |
| Protein-like dissolved organic matter (pDOM), which is ubiquitous in natural waters, is a critical precursor of nitrogenous disinfection byproducts. Recently, the control and elimination of pDOM have been a growing concern during drinking water treatment processes. In this study, a high-performance size exclusion chromatography system coupled with photo-diode array, fluorescence detector, and online organic carbon detector (HPSEC-PDA/FLD/OCD) was used to determine the removal behaviors of different-sized pDOM from two full-scale drinking water treatment plants (DWTPs). Coagulation and activated carbon adsorption were selected for bench-scale experiments to further assess the removal behavior of pDOM during conventional water treatment processes. The results showed that different-sized pDOM fractions exhibited different removal characteristics. Pre-oxidation can effectively remove some tyrosine-like and tryptophan-like components with high MW, and as the oxidization effect was enhanced, more high MW fractions decomposed into low MW ones. Conversely, some aliphatic pDOM fractions in high MW (e.g., aliphatic proteins) were not subject to pre-oxidation removal. The coagulation-sedimentation unit was efficient in removing high MW fractions, specifically tryptophan-like fractions. Additionally, some pDOM components may be released during coagulation. pDOM with low MW and high hydrophobicity were easily removed during activated carbon filtration. However, long-term operation of the activated carbon filter may breed microorganisms, resulting in the partial release of pDOM fractions. Moreover, UV disinfection processes promoted the degradation of low MW pDOM components. Due to the complex water quality and uncontrollable microbial activities, the aforementioned water treatment units did not exhibit a synergistic effect on pDOM removal. In comparison with humic-like substances, pDOM was susceptible to water quality changes, and its removal was limited in the surveyed DWTPs. Therefore, DWTPs must strengthen pDOM monitoring in influent and effluent and adjust the operating parameters of different treatment units in a timely manner. Moreover, the combination of advanced water treatment processes, such as ozone-biological activated carbon process and nanofiltration, should also be considered to strictly control pDOM component removal. |
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