共查询到17条相似文献,搜索用时 93 毫秒
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配水管网中AOC与细菌再生长的关系 总被引:11,自引:2,他引:11
对我国北方A市市区配水管网中可同化有机碳(AOC)与细菌再生长关系的研究表明:降雨量对水源水和管网水中AOC含量影响显著;HPCR2A的计数结果较吖啶橙染色直接计数(AODC)的低2~3个数量级,仅占AODC计数结果的0.1%~2.0%;使用传统琼脂培养基的HPC计数结果又比使用R2A培养基的HPC计数结果低1~2个数量级(前者仅占后者的0.4%~8.4%),有时甚至会出现未检出或检出量极低的情况,不利于试验研究;A市管网水中的AOC含量和异养菌总数的相关性较差,当AOC较低时(<100μg乙酸碳/L)异养菌已经大量繁殖(>104个/mL),而在AOC浓度较高(>200μg乙酸碳/L)的情况下异养菌数量却相对较低(102个/mL)。因此要控制管网水中细菌的再生长,应将AOC的控制与消毒剂余量的控制相结合。 相似文献
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《中国给水排水》2009,25(19)
为提高出水水质的生物稳定性,明确是否应在生物活性炭(BAC)滤池前设置预氧化工艺,比较了预氧化/生物活性炭联用工艺与常规给水处理工艺中AOC的变化规律及对有机物的去除效果.研究发现,常规给水处理工艺对AOC的去除率仅为31.8%,出厂水中高浓度的AOC造成了管网中细菌的再生长.高锰酸钾预氧化与生物活性炭联用工艺对AOC的去除率为67.7%,AOC浓度降至121μg//L,提高了水质的生物稳定性.臭氧预氧化与生物活性炭联用工艺对AOC的去除率为48.3%,低于单独活性炭工艺的;对有机物的去除效果则低于高锰酸钾预氧化/生物活性炭联用工艺的.可见,在生物活性炭前设置高锰酸钾预氧化单元,更有利于去除水中的有机物及保障水质的生物稳定性. 相似文献
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饮用水中磷对微生物生长的限制作用 总被引:9,自引:0,他引:9
阐述了磷在微生物生长中的重要作用以及磷限制微生物生长的作用机理.介绍了饮用水中可以被微生物利用的磷源。着重从三个方面讨论了磷对微生物生长限制作用的最新研究进展:外加磷源提高水处理构筑物的处理效率;磷对管网生物膜的影响;磷对饮用水生物稳定性的影响。 相似文献
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超滤/臭氧氧化工艺对再生水中AOC的去除效果 总被引:1,自引:0,他引:1
如何控制微生物生长、保障水质生物稳定性,是再生水输配与利用过程中关注的重要问题。可同化有机碳(AOC)是评价水质生物稳定性的重要指标。对北京市某再生水厂超滤/臭氧氧化处理过程中AOC浓度及其分子质量分布特性的变化进行了研究,结果表明:二级出水中的AOC主要为分子质量>10 ku的有机物,超滤对二级出水中有机物的去除效果良好,对AOC的去除率达到73%。臭氧氧化可提高有机物的可生化性,导致AOC浓度升高了48%。在二级出水和超滤出水中,AOC物质以分子质量>10 ku的有机物为主,分别占79%和59%;经臭氧处理后,小分子质量(<1 ku)有机物对AOC的贡献明显上升,所占比例达到74%,同时大分子质量(>10 ku)和中等分子质量(1~10 ku)有机物所占的比例分别下降到22%和3%。 相似文献
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以西安市某再生水厂的出水为对象,首先通过静态试验研究了再生水中余氯与异养菌数的消长关系,然后通过测定再生水中碳、磷浓度评价了其生物稳定性,并在此基础上采用生物可利用磷(MAP)阈值法和细菌再生长潜力法探索了碳、磷对再生水中细菌再生长的限制影响。结果表明:即使保持1.35 mg/L的余氯浓度,再生水依然会发生细菌再生长问题,且当停留时间36h后,异养菌按对数增殖;再生水的可同化有机碳(AOC)、生物可降解溶解性有机碳(BDOC)及MAPmax均值分别为454.61μg/L、1.67 mg/L和13.81μg/L,其生物稳定性较差;在碳、磷浓度均超过生物稳定性限值条件下,该再生水中细菌再生长的限制因子为有机碳。 相似文献
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Assimilable organic carbon (AOC) and biodegradable dissolved organic carbon (BDOC):: complementary measurements 总被引:8,自引:0,他引:8
The objective of this study was to evaluate the necessity of measuring both assimilable organic carbon (AOC) and biodegradable dissolved organic carbon (BDOC) as indicators of bacterial regrowth potential. AOC and BDOC have often been measured separately as indicators of bacterial regrowth, or together as indicators of bacterial regrowth and disinfection by-product formation potential, respectively. However, this study proposes that both AOC and BDOC should be used as complementary measurements of bacterial regrowth potential. In monitoring of full-scale membrane filtration, it was determined that nanofiltration (NF) removed over 90% of the BDOC while allowing the majority of the AOC through. Heterotrophic plate counts (HPC) remained low during the entire period of monitoring due to high additions of disinfectant residual. In a two-year monitoring of a water treatment plant that switched its treatment process from chlorination to chlorination and ozonation, it was observed that the plant effluent AOC increased by 127% while BDOC increased by 49% after the introduction of ozone. Even though AOC is a fraction of BDOC, measuring only one of these parameters can potentially under- or over-estimate the bacterial regrowth potential of the water. 相似文献
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《Urban Water Journal》2013,10(8):672-677
This study focuses on reducing the concentration of assimilable organic carbon (AOC) in treated drinking water. Experiments were conducted to evaluate the efficiency of AOC removal by biological activated carbon filters (BACF) in a pilot-scale system. The measured values of AOC in treated drinking water were approximately 59.0 ± 8.6 μg acetate-C/L. The results show that BACFs reduce the total concentration of AOC. The concentration of AOC primarily indicates microbial growth in a water supply network, and the amount of AOC in the water is significantly reduced after BACF treatment. After BACF treatment, the removal of AOC was approximately 58% after 40 min of empty-bed contact time. An AOC empirical equation was established by determining the relationship between water quality parameters, such as total organic carbon, dissolved organic carbon, UV254, ammonia nitrogen, and total phosphorous. 相似文献
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AOC是衡量饮用水生物稳定性的重要指标。研究发现,不同的臭氧投加量下砂滤出水的AOC变化不显著,考虑氧化作用和消毒效果,将最佳的臭氧投量确定为1~2mg/L。生物活性炭(BAC)滤池改善了臭氧氧化后出水的生物稳定性,对TAOC的去除率稳定在28%~65%,而对AOC—P17的去除效果优于AOC—NOX的,因而表现出一定的选择性。较长的空床接触时间(EBCT)并不能保证对AOC的良好去除,但有利于TOC的去除,同时水温的降低一定程度上影响了BAC对AOC的去除效果。 相似文献
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AOC是衡量饮用水生物稳定性的重要指标.研究发现,不同的臭氧投加量下砂滤出水的AOC变化不显著,考虑氧化作用和消毒效果,将最佳的臭氧投量确定为1~2 mg/L.生物活性炭(BAC)滤池改善了臭氧氧化后出水的生物稳定性,对TAOC的去除率稳定在28%~65%,而对AOC-P17的去除效果优于AOC-NOX的,因而表现出一定的选择性.较长的空床接触时间(EBCT)并不能保证对AOC的良好去除,但有利于TOC的去除,同时水温的降低一定程度上影响了BAC对AOC的去除效果. 相似文献
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