Effects Of Ozone On The Production Of Biodegradable Dissolved Organic Carbon (BDOC) During Water Treatment

This article deals with the oxidation effect of ozone on the increasing fraction of biodegradable organic matter with the “ozotest” method, a laboratory technique which simulates the effect of ozonation and allows a complete oxidation assessment. Ozone treatment was performed on river water samples and sand filter effluent samples. Ozone consumption, reduction of UV absorbance and BDOC formation were monitored with applied ozone doses from 0 to 10 mg/L and with contact times from 0 to 60 min. The BDOC formation was optimum at an applied ozone dose of 0.25-0.5 mg O₃ per mg DOC (contact time = 5 min) corresponding to apparition of traces of residual ozone and maximum UV reduction. Maximum ozone consumption, UV reduction and BDOC formation occurred simultaneously during the first two minutes of treatment. Concerning BDOC formation, applied ozone dose showed a greater effectiveness than contact time. For the same quantity of consumed ozone, a short contact time associated with a high ozone dose was preferable to a long contact time and a low ozone dose.     

给水管网中可生物降解溶解性有机碳的变化

以地表水为水源的水厂及相对应的给水管网为对象,研究可生物降解溶解性有机碳(BDOC)的变化及主要影响因素.结果表明:在给水管网中BDOC的变化是余氯和细菌总数两个因素相互制约的结果;同时,水温也是一个很重要的因素,不同的季节BDOC的变化趋势也不同.     

饮用水生物稳定性的研究进展与评述

饮用水生物稳定性的研究是近年来水处理领域的研究热点。该文分析了管网中细菌再生长的机制及其影响因素。系统论述了饮用水生物稳定性与其评价指标(AOC与BDOC)间的关系和特性，总结了生物稳定性在制水工艺和给水管网中的变化规律；并就制备生物稳定性饮用水的工艺提出了建议。     

水源水中AOC和BDOC的去除

试验研究了预氯化+常规处理工艺(混凝-沉淀-砂滤)对某水源水中AOC和BDOC的去除,结果表明:水源水中AOC和BDOC占总有机碳(以NPOC计)的比值都在9.5%左右,AOC和BDOC含量基本相同,平均质量浓度分别为316.2μg/L和329μg/L。常规工艺对AOC几乎没有去除作用,多数情况下出厂水AOC浓度在氯的氧化作用下升高,平均增加71%;出厂水AOC平均质量浓度为206.4μg/L,属于生物不稳定饮用水。BDOC的平均去除率为63.8%,偏高于一般研究结果。     

Evaluation of biodegradability of NOM after ozonation

The major purpose of this study was to develop a simple procedure to describe the kinetics of biodegradation of natural organic matter (NOM) in drinking water and to use this procedure to evaluate changes in the concentration of biodegradable organic matter during ozonation and biotreatment. The proposed approach quantitatively describes the formation and removal of rapidly and slowly biodegradable fractions of NOM. This study showed that, depending on source water, ozonation of NOM may result in either minimal formation of biodegradable organic carbon (BDOC), or the formation of predominantly rapidly biodegradable NOM, or in the formation of both rapidly and slowly biodegradable NOM. The kinetic data obtained in this study suggest that while conventional biofiltration processes are capable of removing the rapidly biodegradable fraction, slowly biodegradable organic matter would remain in the filter effluent and may cause bacterial regrowth in the distribution system. An addition of a small amount of easily biodegradable carbon ("stimulated" biodegradation) to ozonated water appears to be effective for the removal of slowly biodegradable organic matter.     

Assimilable organic carbon (AOC) and biodegradable dissolved organic carbon (BDOC):: complementary measurements

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.     

黄河水源供水系统生物稳定性分析

以黄河水为水源的济南市供水系统为研究对象,选取生物可降解溶解性有机碳(BDOC)作为评价生物稳定性指标,分析地表水厂和管网的水质生物稳定性变化.结果表明:水厂常规净水工艺处理后BDOC去除率为10％～32％,出厂水BDOC在0.1～ 0.2 mg/L之间,低于0.2 mg/L生物稳定性水中BDOC的建议限值.出厂水水质直接影响管网水质,随着管网延伸BDOC相对稳定;BDOC与浊度、总有机碳(TOC)等指标呈正相关.水厂采用臭氧活性炭深度过滤工艺改造后,BDOC值进一步降低,生物稳定性提高.     

饮用水BDOC、AOC处理技术研究进展

围绕饮用水的生物稳定性，分析了常规水处理工艺对BDOC、AOC的影响，提出强化混凝和强化过滤的方法可改善出厂水的生物稳定性。讨论了生物氧化、臭氧氧化、活性炭吸附、臭氧-生物活性炭及膜过滤等工艺对饮用水中BDOC、AOC的去除效果，提出了提高出厂水生物稳定性的措施。     

臭氧氧化对可溶性有机物构成的研究

实验目的在于对溶解性有机物进行分类及考察，研究臭氧氧化影响四种溶解性有机物：1．可生物降解不可吸附；2．可生物降解可吸附；3．可吸附不可生物降解；4．不可吸附不可生物降解。（NA＆BDOC、B＆ADOC、NB＆ADOC、NRDOC）的因素及趋势。实验结果表明臭氧不能同时去除四种溶解性有机物。而是影响它们所占比例．使可生物降解性有机物增加，可吸附性有机物减少。根据实验结果可优选出后续生物活性炭净水效果的最佳的臭氧投加量和停留时间。实验结果可为工程设计提供有益的参考价值。     

以AOC评价管网水中异养菌的生长潜力

对澳门管网水中异养菌二次生长和水质生物稳定性指标的相关关系的研究结果表明：（1）澳门管网水基本属于生物稳定的饮用水；（2）澳门管网沿途水中可同化有机碳（AOC）和可降解溶解性有机物（BDOC）的变化不明显；（3）降水量和水温对于AOC的季节变化有很大影响，而原水水质、处理工艺和水温则对BDOC的季节变化有很大影响；（4）由于管网水中AOC和异养菌计数（HPC）有明显的相关关系，而BDOC与HPC间无明显的相关关系，故建设将AOC作为评价管网水中异养菌二次生长潜力的首要指标。