臭氧氧化联合A/A/O工艺污泥减量的可行性

针对目前污水处理厂污泥产量大、处理处置费用高的问题,该文以A/A/O工艺构建了模拟城市生活污水小试处理系统,通过添加臭氧研究不同臭氧投加量对出水水质及污泥产率的影响。结果表明在试验进水条件下,系统的稳定污泥浓度为2 000~3 000 mg/L,且当将约50%产泥量的污泥经臭氧化返回至系统中时,加入臭氧与不加臭氧的两套系统显示出相当的污水处理能力。在不同污泥浓度和相同污泥负荷(0.91 g COD/g SS.d)条件下,当MLSS为1 500、2 500、3 500和4 500 mg/L时最佳臭氧投加量分别为0.095、0.11、0.129和0.129 g O3/g SS。     

臭氧催化氧化深度处理印染废水的研究

采用臭氧催化氧化工艺对二级生化出水中难降解有机物进行深度处理试验。结果表明,投加H_2O_2作为催化剂能明显提高出水COD去除率,当H_2O_2投加量为0. 10 m L/L,反应时间为5min时,出水COD值可从93 mg/L降至47 mg/L,比臭氧率R值达到0. 92,臭氧利用率相对最高且该条件下COD去除率达49%。     

臭氧催化氧化处理炼油生化尾水的研究

针对生化后炼油废水CODCr无法达标的问题,使用负载Mn-Fe氧化物活性相的陶粒催化剂。采用臭氧催化氧化工艺处理炼油生化尾水。研究中考察了pH、温度、催化剂投加量和臭氧用量等工艺条件对生化尾水中CODCr处理效果的影响。结果表明,当废水初始pH=7,臭氧用量为6.3 mg/min,催化剂投加量为8 g/L时,催化氧化效果最优。室温(22℃)下反应30 min后,出水CODCr浓度为48 mg/L,满足了炼油企业排放标准。所制备的催化剂使用后活性稳定,多次使用后活性无明显降低。     

臭氧催化氧化处理炼油生化尾水的研究

针对生化后炼油废水CODCr无法达标的问题,使用负载Mn-Fe氧化物活性相的陶粒催化剂。采用臭氧催化氧化工艺处理炼油生化尾水。研究中考察了pH、温度、催化剂投加量和臭氧用量等工艺条件对生化尾水中CODCr处理效果的影响。结果表明,当废水初始pH=7,臭氧用量为6.3 mg/min,催化剂投加量为8 g/L时,催化氧化效果最优。室温(22℃)下反应30 min后,出水CODCr浓度为48 mg/L,满足了炼油企业排放标准。所制备的催化剂使用后活性稳定,多次使用后活性无明显降低。     

涡流空化协同臭氧氧化污泥减量实验研究

以城镇污水处理厂二沉池剩余污泥为处理对象,采用涡流空化协同臭氧氧化污泥减量的工艺,探究了两者协同作用下污泥的减量效果、碳源释放效果以及氮磷元素的溶出量。结果表明:当臭氧投加量为15 mgO_3/gSS时,MLSS从3 500 mg/L下降至1 140 mg/L,去除率达67.4%。MLVSS从1 130 mg/L下降至210 mg/L,去除率达81%。污泥上清液中SCOD从51 mg/L增加至358 mg/L,是初始浓度的7.02倍,DD_(COD)达到13.59%。B/C从0.17增加至0.3,可生化性得到显著改善。TN从2.86 mg/L增加至33.33 mg/L,是初始浓度的11.65倍。TP从5.1 mg/L增加至13.08 mg/L。     

臭氧—曝气生物滤池深度处理印染废水研究

印染废水经物化和生化二级处理后,剩余部分可溶性难降解COD难以用常规方法去除。文章以臭氧氧化组合曝气生物滤池工艺处理上述废水,对臭氧投加量、氧化时间、曝气生物滤池停留时间、滤料选型做了多方面研究,最终结果表明:当臭氧投加量为40~50 mg/L,曝气生物滤池停留时间为3 h的条件下,经"臭氧+火山岩陶粒曝气生物滤池"工艺处理后COD平均值由95.9 mg/L降至55.3 mg/L,为该工艺的工程应用积累了理论基础。     

UV/O3氧化处理磺化泥浆体系钻井废水

用紫外光催化-臭氧(UV/O3)氧化处理磺化泥浆体系钻井废水,考察了pH、初始COD、臭氧投加量等因素的影响.结果表明:由于钻井废水中含有羟基自由基可清除碳酸氢根离子,所以钻井废水UV/O3氧化在pH为3.0时的效果好于中性和碱性条件;初始浓度的降低和臭氧投加量的增多均可提高UV/O3氧化去除钻井废水COD的速率,但是随着臭氧投加量的增多,相应的臭氧指数(OI)显著增大.当臭氧投加量为810 mg/h时,氧化60min COD可从647mg/L降至96mg/L,但臭氧指数高达4.52,显得并不经济.由于UV/O3氧化可大大提高钻井废水的可生化性,所以可以先用UV/O3预氧化钻井废水,然后再用生物法处理,这样可大幅降低处理费用.     

含炭高密度沉淀池/臭氧催化氧化工艺处理化工污水厂二级出水试验研究

本文研究了投加不同浓度粉末活性炭对高密度沉淀工艺和臭氧催化氧工艺处理某化工园区污水处理厂二级出水的影响。结果表明:投加粉末活性炭不影响高密度沉淀池对SS和TP的处理效果,但可以提高对COD的去除率,投加20、40、60、80mg/L时,COD去除率分别增加了9%、18%、20%和21%;当通入臭氧反应后,粉末活性炭投加量为20 mg/L时,臭氧催化氧化工艺的COD去除率增加了7%,而投加量大于20 mg/L,会降低臭氧催化氧化工艺的COD去除率。     

水厂深度处理工艺中臭氧投加量探讨

臭氧生物活性炭深度处理是降低水中微量有机物的关键净化工艺。为确定臭氧的合理投加量,利用小试装置开展了臭氧氧化对砂滤池出水的研究。结果表明:随着臭氧投加量的增加,CODMn、总有机碳(TOC)的去除率均有所增加,但幅度弱于UV254;当臭氧的投加量达到3.0 mg/L时,臭氧氧化后的生物可降解溶解性有机碳(BDOC)可增加30%以上,UV254与TOC的比值趋于稳定;砂滤出水的溴离子浓度为100~300μg/L的情况下,当臭氧的投加量达到3.5 mg/L时仍未检测到溴酸盐。综上所述黄浦江原水水厂深度处理工程运行时,臭氧的投加剂量控制在2.5~3.5 mg/L是安全合理的。     

微泡臭氧处理反渗透浓缩液与剩余污泥混合液的试验研究

采用微泡臭氧接触池,探讨了微泡臭氧氧化对反渗透(RO)浓缩液和剩余污泥处理效果。结果表明,随着臭氧投加量的增加,处理液的SS、色度下降较快,COD则有先小幅上升再下降的趋势,但当臭氧增加到某一程度时,由于臭氧的矿化作用使得处理液的SS、COD、色度都趋于稳定。臭氧最适投加量为185 mg O3/L。     

Purification of Phenolic Wastewater Using Aerobic Bio-oxidation Combined with Activated Carbon Treatment and Ozonation

The combined process – aerobic bio-oxidation with activated carbon addition and ozonation was studied (ABO/AC/O3). The performance of the process was compared with conventional aerobic bio-oxidation (ABO). The studies were carried out in two continuous and periodic reactors to evaluate the purification efficiencies (in terms of COD, BOD and resorcinols removal), excess sludge generation and stability of the bioreactors against shock loadings. The parameters in continuous combined process were as follows: organics loading was 620 mgCOD/(day·L), activated carbon concentration 1g/L and ozone dose 2.45 mgO₃/L (mg ozone per liter of treated water). In periodic reactors the combined process was studied at lower activated carbon concentration and ozone dose (0.3 g/L and 0.57 mg/L respectively).

The results indicated that compared with conventional ABO, the co-effect of AC addition and short-termed (less than 1 week) or intermittent ozonation improved the removal of COD and BOD, while the longer period of ozonation resulted in reduction of excess sludge concentration in the bioreactor. The impact of AC and ozone on the ABO in the combined process did not concern only increased biomass activity, but AC and ozone improved also settleability of activated sludge and enhanced stability of the bioreactor to shock loadings.     

臭氧尾气回用对曝气池污泥影响研究

将活性污泥分别在14.68、30.72、43.84 mg/L 3种臭氧浓度下进行氧化,同时以纯氧曝气作为平行实验,考察臭氧尾气对活性污泥的影响。结果表明,污泥经纯氧曝气后,在反应时间内并无明显变化,但在臭氧氧化过程中,污泥ATP下降,同时上清液中COD、TP、TN上升,且臭氧浓度越高,变化速率越大,其原因为污泥发生了溶胞现象;臭氧氧化后,污泥MLSS、MLVSS减少,污泥呼吸速率下降,但沉降性得到改善,同样随着臭氧浓度的升高,变化更为显著。经14.68、30.72 mg/L臭氧氧化后的污泥,其硝化能力、生化能力与反应前并无明显差距,而经43.84 mg/L臭氧氧化后污泥的硝化能力、生化能力明显弱于反应前。     

Effect of Ozonation on Biodegradability Characteristics of Surplus Activated Sludge

The study investigates the effect of sludge ozonation on solid matter species, disintegration properties, sludge components, and solubilization characteristics under different operating conditions. Ozonation of surplus activated sludge samples taken from the secondary settling tank of a domestic wastewater treatment plant indicates that soluble nitrogen, phosphorus and COD concentrations proliferate as a consequence of extending the ozone feeding time. A steady increase both in soluble nitrogen concentration and ratio of organic phosphorus to soluble phosphorus is observed through ozonation where specific ozone doses range between 4 and 11 mg O₃/g SS. Combined treatment of chemical oxidation and aerobic biodegradation to surplus activated sludge is also applied to improve the biodegradability of organic matter by partial chemical oxidative pretreatment with as little specific ozone consumption as possible. The partial oxidation by integrated ozonation is operated as a pre-oxidation step for the subsequent biological degradation, due to the fact that the competition with biological degradation in removing biodegradable organic compounds is avoided and most probably a more biodegradable sludge composition is obtained by means of ozonation. Combined treatment of chemical oxidation and aerobic biodegradation conducted to scrutinize the synergic effect of the coupled treatment system reveals that TS and COD removal efficiencies of ozonated sludge samples cannot be improved beyond the third aerobic biodegradation step.     

Sludge Ozonation and its Application to a New Advanced Wastewater Treatment Process with Sludge Disintegration

The applicability of sludge ozonation on wastewater treatment processes was investigated to reduce the amount of excess sludge without losing phosphorus removal efficiency. Solubilization degree per ozone consumption for general sludge was in the range from 2.4 to 5.8 gSS/O₃ and from 4.1 to 7.7 gCOD/gO₃. Around 80 to 90% of solubilized organics was biodegradable at a solubilization degree of 0.3. Based on the experimental results, a lab-scale plant with sludge ozonation and phosphorus crystallization was constructed to investigate the treatment performance. Amount of excess sludge was reduced by 93% with almost complete removal of soluble BOD and phosphorus removal efficiency of more than 80%. The percentage of the effluent COD_Cr discharge increased from 10% to 14–17% after installing ozonation and crystallization because of the formation of non-biodegradable organic substances in ozonation process. Energy consumption of the innovative advanced process is comparable or can be even smaller than that of the conventional anaerobic/oxic (A/O) process in spite of the installation of ozonation and crystallization.     

Toxicity and Biodegradability Behavior of Xenobiotic Chemicals Before and After Ozonation: A Case Study with Commercial Textile Tannins

Ozonation of a natural tannin (NT; COD_o?=?1195 mg/L; TOC_o?=?342 mg/L; BOD_5,o?=?86 mg/L) and a synthetic tannin ST; COD_o?=?465 mg/L; TOC_o?=?55 mg/L; BOD_5,o?=?6 mg/L) being frequently applied in the polyamide dyeing process was investigated. Synthetic wastewater samples containing these tannins individually were prepared and subjected to ozonation at varying ozone doses (625– 1250 mgO₃/L wastewater), at pH?=?3.5 (the application pH of tannins) and pH?=?7.0 at an ozone dose of 1125 mgO₃/L wastewater. The collective environmental parameters COD, TOC, BOD₅, UV₂₅₄ and UV₂₈₀ (UV absorbance at 254 nm and 280 nm, representing aromatic and unsaturated moieties, respectively) were followed during ozonation. Changes in the biodegradability of the tannins were evaluated in terms of BOD₅ measurements conducted before and after ozonation. In addition, activated sludge inhibition tests employing heterotrophic biomass were run to elucidate the inhibitory effect of raw and ozonated textile tannins towards activated sludge biomass. Partial oxidation (45% COD removal at an ozone dose of 750 mg O₃/L wastewater and pH?=?3.5) of ST was sufficient to achieve elimination of its inhibitory effect towards heterotrophic biomass and acceptable biodegradability improvement, whereas the inhibitory effect and biodegradability of NT could not be reduced via ozonation under the same reaction conditions.     

臭氧化污泥减量化技术的研究进展

臭氧化技术是一种极具潜力的无二次污染的污泥处理技术.本文综述了在污泥减量化中物理技术、生化技术结合臭氧化的处理技术,以及改进臭氧利用效率的技术的应用研究进展,并指出今后的研究方向.     

Intermittent Ozone Application in Aerobic Sludge Digestion

Excess biological sludge, WAS, produced during activated sludge process is a growing problem for the utilities owing to the stringent regulations now imposed worldwide. One method of handling the excess sludge is to digest it, to reduce its amount and to stabilize it. Aerobic digestion is particularly suitable for nutrient treating plants as sludge should not be exposed to anaerobiosis since this will lead to release of accumulated phosphorus. A novel and patented ozone-assisted aerobic sludge digestion process (PCT/TR2010/000213) is shown to appreciably shorten the 15–30-day aerobic digestion period and the extent of solids destroyed. WAS samples were ozonated for different periods in Erlenmeyer flasks, once a day, on each of four consecutive days. Flasks were continuously aerated between ozone applications. The MLVSS, MLSS, COD and OUR parameters were measured routinely during the course of four days of digestion in order to optimize the process. As a result 22.6%, 40%, 75% and 84% MLVSS reductions were obtained at total ozone applications of 0.42, 0.64, 0.85 and 1.27 mg O₃ g^?1 MLSS, at the end of the fourth day. Hence, it became possible to save on contact time as well as achieving a bio-solids digestion far exceeding the standard aerobic process, which is 40–50% in 15–30 days, at the expense of a minimum of ozone dose. The developed process is deemed superior over side-stream ozonation where ozone is applied to the return activated sludge, RAS, line; in that it does not cause any reduction in active biomass amount maintained in the aeration tank. Conversely, reduction in active biomass concentration results in reduced treatment efficiency.     

关于臭氧氧化污泥减量技术的研究

活性污泥法处理污水产生的大量剩余污泥已成为大多数污水处理厂亟待解决的问题,而污泥减量就是从源头上减少污泥的产生。臭氧氧化技术是一种有潜力的清洁无二次污染的污泥减量技术。文中阐述了臭氧在污泥减量技术中的应用背景及基本原理,从不同角度分析了臭氧氧化技术的应用现状,指出了最新的研究热点以及当前存在的问题和未来可能的发展方向。     

Biological Nitrogen Removal Using the Supernatant of Ozonized Sludge as Extra Carbon Source

A sludge ozonation process with lab-scale anaerobic/oxic (A/O) system was used to investigate the utilization of the ozonized sludge (OS) supernatant as extra carbon source for denitrification. The optimal ozone dose for the sludge ozonation was 0.2 gO₃/gSS. The concentrations of SCOD, BOD, NH₃-N and TN in the supernatant increased respectively at this ozone dose. In the meantime, the sludge was significantly reduced. The OS supernatant had negative effect on nitrification because of low pH and alkalinity. After alkalinity adjustment, the A/O with the OS supernatant as the extra carbon source achieved a nitrogen removal rate of 78%, which was very close to the control experiment using glucose (79%).     

Ozone Application for the Improvement of UASB Reactor Effluent. II. Toxicity Evaluation

In order to improve the effluent from domestic sewage treatment through an anaerobic process in an upflow anaerobic sludge blanket reactor (UASB), CETESB - The Environmental Protection Agency for Sao Paulo State, and FILSAN - Equipamentos e Sistemas S/A, developed a joint program to study the effectiveness of ozonation of the effluent as a post-treatment process. As the effluents treated by this system could contain toxic chemicals, Daphnia similis toxicity tests were applied. Two ozonation conditions were evaluated: (1) contact time of 30 min, mean ozone application dosage of 15.9 mg/L; (2) contact time of 50 min, mean ozone application of 16.7 mg/L. Toxicity reduction occurred for all samples but one. The ozonation system eliminated the residual toxicity associated with the effluent treated by the UASB reactor.