臭氧+超滤对二级出水溶解性有机物的特性研究

以城市污水处理厂二级出水中溶解性有机物为研究对象,采用臭氧为预处理手段,以4000、6000、10000、20000、30000Dalton的聚醚砜超滤膜(polyether sulfone,PES)对二级出水中溶解性有机物进行研究。结果表明:1引起膜通量下降的溶解性有机物的分子量主要在大于20000Dalton的范围内;2城市污水处理厂二级出水中溶解性有机物的大小主要分布在小于4000Dalton的范围内;3臭氧能使高分子量有机物低分子化。     

长三角区域饮用水水源中可同化有机碳的研究

对长三角区域不同饮用水水源中可同化有机碳（AOC）进行了测定。试验结果表明：长江（镇江段）和钱塘江（杭州段）原水中AOC平均浓度分别为102μg/L和113μg/L．黄浦江上游原水中AOC浓度相对较高，平均值为188μg／L。三种不同原水中AOC均以能被P17细菌利用的有机物为主。主要包括大部分氨基酸、多种羧基酸、碳水化合物和芳香族等有机物，而能被NOX细菌利用的羧基酸在原水中只占一小部分。长江（镇江段）和钱塘江（杭州段）原水中AOC占溶解性有机碳（DOC）的平均比例分别为5.9％和6.1％，黄浦江上游原水中AOC占DOC的平均比例为3．3％。长三角区域饮用水水源中AOC与DOC呈一定的正相关性．AOC／DOC与DOC呈一定的反相关性。     

给水工艺对不同分子质量有机物的去除规律研究

通过给水处理工艺中试系统,研究了溶解性有机碳(DOC)在各工艺单元出水640的分子质量分布,探讨了对不同分子质量有机物的去除规律.曝气生物滤池(BAF)去除最好的是相对分子质量在3k～10k的DOC:预臭氧化对相对分子质量＞1k的DOC均有去除效果.而对相对分子质量＜1k的DOC则产生了积累;常规处理对＞30k和10k～30k的DOC去除率分别达到93.7%和78.4%,而对10k以下的DOC去除作用不强;因可被臭氧分解的有机物基本在预臭氧阶段已处理掉,所以后臭氧对有机物去除不明显;炭滤池对各分子质量段的有机物均有去除效果,尤其对BAF和常规处理效果不好的相对分子质量＜10k的DOC去除效果很好.     

臭氧氧化对生物活性炭床的作用过程分析

通过对原水有机物臭氧氧化前后种类和结构变化的分析,探讨了臭氧氧化对生物活性炭处理有机物的降解特征.结果表明,臭氧氧化除将少部分有机物直接氧化分解为无机物外,主要作用是将芳香族,链烃类和脂肪族等氧化后为脂肪族、羧酸类和酯类等易生物降解的有机物,提高了可生化性;水中有机物的相对分子质量从3 000～6 000降低至2 000～3 000,特别是小于500的有机物含量显著增加.臭氧氧化后水中的残余臭氧对改善活性炭的微孔结构有一定作用.从吸附作用和生物降解作用对溶解性有机炭降解所起的贡献看,臭氧氧化并不利于发挥活性炭的吸附作用,而是大大增强了生物降解的作用.     

MBR工艺处理餐饮废水中DOM组分的特性

通过组分划分试验,对平板膜生物反应器中的溶解性有机物进行分离得到四种组分,并借助于分子量技术、荧光技术深入研究各组分对膜污染的影响。结果表明强疏水性（HPO）组分表现出最强的膜污染趋势,而弱疏水性（TPI）组分呈现出最高的可生物降解性,生物降解去除率可达91．8％。     

炼油化工污水中溶解性难生物降解COD的测定研究

基于含水介质中有机物生物降解性评定方法,提出了一种优化、简单、易操作的间接测定污水中溶解性难生物降解COD的方法。并对某石化污水中溶解性难生物降解COD进行了测定分析,实验结果为该石化污水深度处理工艺的选择提供了设计依据和基础。     

浅谈饮用水生物稳定性评价指标及体系

对比分析了国内外不同生物稳定性控制指标与配水系统中水的生物稳定性关系,并分别就BDOC(可生物降解溶解性有机碳)、AOC(生物可同化有机碳)、TP(磷)以及AOC-TDWMS和用细菌生长潜力(BGP)各自的测定方法及工程研究中的应用进行比较。饮用水生物稳定性作为一个新兴研究课题尚处于探索阶段,对各控制指标的监测方法的研究和改进以及寻求更好的控制指标及体系来控制饮用水生物稳定性,具有重要的社会现实意义。     

臭氧-生物活性炭联用工艺去除腐殖酸的试验

在选取UV254作为腐殖酸浓度表征指标的基础上,考察了初始腐殖酸浓度、Mn2+浓度、p H及常规处理对臭氧-生物活性炭出水效果的影响。结果表明臭氧-生物活性炭工艺对腐殖酸的去除是在臭氧氧化分解、活性炭吸附和生物降解的共同作用下完成。腐殖酸初始浓度升高,出水腐殖酸的去除率反而下降;当原水中存在Mn2+离子时,Mn2+的催化作用凸显,且在Mn2+投加量为0.75 mg/L条件下,臭氧-生物活性炭出水的腐殖酸去除效果最佳;p H的升高和前置混凝沉淀均有利于后续臭氧-生物活性炭对腐殖酸的去除。     

臭氧氧化法除地表水有机物试验研究

本文阐述臭氧化法除地表水有机物的重要意义，实验结果表明：臭氧氧化有机物的总氧化速率受活化控制，影响氧化率的最高显著因素是温度，其次是ｐＨ，接触时间等，臭氧很容易氧化腐植酸，在３０℃，ｐＨ９．０～１０．０，７ｍｉｎ内，ＣＯＤ去除率可达６０％以上，对邯郸热电厂生产处理也取得良好效果，３５℃，ｐＨ７．４～７．６，１０ｍｉｎ内，ＣＯＤ去除率可达６７％，可望将臭氧化水处理工艺应用于电厂水处理。     

预臭氧 BAC工艺处理微污染原水参数优化与有机物去除特性

采用中试装置研究了预臭氧生物活性炭工艺对长江南京段微污染原水有机物的去除特性,考察了臭氧投加量和臭氧接触时间对预臭氧氧化、砂滤及生物活性炭单元中DOC、BDOC、CODMn、UV254和微量有机污染物去除的影响。结果表明当臭氧投加量为3 mg/L、臭氧接触时间为10 min时,预臭氧氧化单元中DOC、CODMn和UV254的去除率分别达到19％、31％和78％,BDOC增长了33％;砂滤单元四种指标的去除率分别为25％、52％、42％和44％,而生物活性炭滤柱对四种污染物指标的去除率分别为46％、83％、52％和20％,高于常规处理工艺。整个工艺对三种微量有机物（1,2,4三氯苯、DMP和DEHP）的去除率也分别达到了60％、68．6％和68．8％。与未投加臭氧相比,臭氧的投加有效促进了砂滤和生物活性炭对有机污染物的去除。采用预臭氧生物活性炭工艺处理微污染长江原水,有效提高了有机污染物的去除效果,可保障出水水质安全。     

Effects Of Ozone-Hydrogen Peroxide Combination On The Formation Of Biodegradable Dissolved Organic Carbon

The effects of ozone and ozone/hydrogen peroxide on BDOC formation were studied with the “Ozotest” method, a laboratory technique that permits the assessment of oxidation efficiency. Oxidation treatments were performed on river water and sand filter effluent samples. Ozone consumption, reduction of UV absorbance, and BDOC formation were monitored during the experiments. The ratio of 0.35-0.45 mg H₂O₂ per mg O₃ used to degrade pesticides also was optimal for the oxidation of organic matter. BDOC formation versus ozone dose curves with ozone alone or ozone/peroxide system were similar. BDOC formation was optimum at an applied ozone dose of 0.5-1 mg O₃/mg C (contact time = 10 min). The ozone/peroxide system yielded lower BDOC values than ozone alone, a phenomenon related to differences in byproducts generated by the two oxidative systems. Moreover, reduction of the concentration of DOC was higher with ozone/hydrogen peroxide than with ozone alone. For both oxidant systems, BDOC formation occurred during the first minute of treatment.     

The Formation of Filter-Removable Biodegradable Organic Matter During Ozonation

Biodegradable organic matter formed during the ozonation of natural waters was fractionated into rapidly and slowly degradable components based on measurements of biodegradable organic carbon (BDOC). The rapidly degradable fraction (BDOC_rapid) was defined using the specific BDOC reactor incubation time that resulted in biodegradation similar to that in a pilot scale biofilter. Ozone dose was found to increase the formation of BDOC_rapid up to a transferred dose of 1.0 to 1.5 mg O₃/mg DOC. This fraction was insensitive to DOC quantity or character. The formation of BDOC_slow was not sensitive to ozone dose but was sensitive to DOC quantity.     

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.     

Formation and Removal of Biodegradable Ozonation By-Products during Ozonation-Biofiltration Treatment: Pilot-Scale Evaluation

An ozonation-biological filtration pilot-scale study was performed to evaluate the formation and removal of biodegradable ozonation by-products. The formation of aldehydes and ketoacids was found to be proportional to the DOC concentration and ozone dosage, and a strong relationship between the formation of aldehydes, ketoacids, and biodegradable dissolved organic carbon (BDOC) was observed. Four types of granular activated carbon (GAC) and one nonadsorbing medium, biolite, were employed to evaluate the performance of biofiltration for removing ozonation by-products. It was observed that GAC filters developed biological activity sooner than the biolite filter. Once developed, biofilters, either GACs or biolite, were particularly effective in the removal of aldehydes, ketoacids and BDOC.     

臭氧、臭氧/双氧水催化氧化深度处理化工废水

对比了臭氧、臭氧催化氧化、臭氧/双氧水和臭氧/双氧水催化氧化4种工艺深度处理化工废水的效果,结果表明,当进水COD和色度分别为95.7 mg/L和90倍时,4种工艺出水的COD去除率分别为23.66%、26.77%、29.24%、32.97%,色度去除率分别为64.44%、64.44%、82.22%、82.22%,催化剂和双氧水均能小幅强化臭氧氧化效果。连续臭氧氧化可使出水COD降至20 mg/L,同时当臭氧投加量为60 mg/L时,4种工艺出水均具有一定的可生化性,满足后序生化工艺的需求。     

Characteristics of adsorption and biodegradation of dissolved organic carbon in biological activated carbon pilot plant

The dissolved organic carbon (DOC) properties for the influent of the BAC pilot plant have shown a 42% biodegradable fraction and a 58% non-biodegradable fraction. The biodegradable dissolved organic carbon (BDOC) was degraded entirely by biodegradation; the removal efficiency was 65–83%. The BDOC removal efficiency at empty bed contact time (EBCT) 15 minutes was larger than at EBCT 8 minutes. At increasing EBCT, a more slowly biodegradable fraction of BDOC (H₂) was utilized. The non-biodegradable dissolved organic carbon (NBDOC) was removed mostly by adsorption, and the removal amount was 24–58%. Therefore, the DOC was removed by adsorption and biodegradation; the removal efficiency by biodegradation was 31%, and that by adsorption was 24%. The breakthrough behaviors of DOC and NBDOC continued to be saturated as the bed volume increased, whereas the BDOC breakthrough curves maintained a certain ratio according to the bed volume.     

Effects Of Ozone On Biodegradable Dissolved Organic Carbon And Heterotrophic Plate Counts In The Distribution System

The impacts of ozone dose in the formation of biodegradable dissolved organic carbon (BDOC) were studied at the North Bay Regional Water Treatment Plant (NBR). Increasing the ozone to total organic carbon ratio to 0.45 (mg/mg) resulted in the formation of BDOC. Sedimentation and filtration/adsorption were effective in removing BDOC to non-measurable levels prior to the water entering the distribution system. Data from an on-going distribution system monitoring program indicate no discernible adverse impacts on microbiological parameters from using ozone during water treatment. Heterotrophic plate count (HPC) levels were similar before and after the use of ozone. Maintaining chlorine residual levels above 0.3 mg/L appears to be important for controlling HPC levels.     

Ozone treatment of textile effluents and dyes: effect of applied ozone dose,pH and dye concentration

The ozonation of wastewater supplied from a treatment plant (Samples A and B) and dye‐bath effluent (Sample C) from a dyeing and finishing mill and acid dye solutions in a semi‐batch reactor has been examined to explore the impact of ozone dose, pH, and initial dye concentration. Results revealed that the apparent rate constants were raised with increases in applied ozone dose and pH, and decreases in initial dye concentration. While the color removal efficiencies of both wastewater Samples A and C for 15 min ozonation at high ozone dosage were 95 and 97%, respectively, these were 81 and 87%, respectively at low ozone dosage. The chemical oxygen demand (COD) and dissolved organic carbon (DOC) removal efficiencies at several ozone dose applications for a 15 min ozonation time were in the ranges of 15–46% and 10–20%, respectively for Sample A and 15–33% and 9–19% respectively for Sample C. Ozone consumption per unit color, COD and DOC removal at any time was found to be almost the same while the applied ozone dose was different. Ozonation could improve the BOD₅ (biological oxygen demand) COD ratio of Sample A by 1.6 times with 300 mg dm^?3 ozone consumption. Ozonation of acid dyes was a pseudo‐first order reaction with respect to dye. Increases in dye concentration increased specific ozone consumption. Specific ozone consumption for Acid Red 183 (AR‐183) dye solution with a concentration of 50 mg dm^?3 rose from 0.32 to 0.72 mg‐O₃ per mg dye decomposed as the dye concentration was increased to 500 mg dm^?3. © 2002 Society of Chemical Industry     

Ozonated Nutrient Solution Treatment as an Alternative Method for the Control of Root-Knot Nematodes in Soilless Cultivation

ABSTRACT

Root-knot nematodes (Meloidogyne incognita) are plant parasitic worms that widely influence the agricultural production including soilless cultivation. In this study, we investigated the inactivating effect of ozonated nutrient solution on the root-knot nematode juveniles in both nutrient solution and substrate, as well as the in vitro egg hatching. The results showed that twice ozonation treatments with dissolved ozone concentration (DOC) at 0.5 mg/L resulted in a mortality at 90.8% for in vitro study. DOC of 4.0 mg/L with three treatment repeats in the substrate experiment resulted in a mortality at 88.3%. Our results imply that the application of ozonated nutrient solution might be a feasible method in soilless cultivation for the control of root-knot nematodes. In practical application, ozonation treatment should be conducted with appropriate DOC and treatment repeats.