臭氧氧化印染废水生化出水的生化降解特性

测定了不同比臭氧消耗量条件下,印染废水生化出水中生化可降解溶解性有机碳（BDOC）在28 d内的变化过程,并对接种培养前后的三维荧光光谱进行了分析.结果表明,臭氧氧化能有效降低印染废水生化出水的色度和芳香度,明显提高可生化性.在比臭氧消耗量2.7 mg.mg-1条件下,预计臭氧氧化和生物滤池联用技术对DOC的去除率约为54%.另外,亲水性有机物对BDOC的贡献率与比臭氧消耗量呈正比关系.类腐殖和类色氨酸物质的荧光强度在一定程度上反映了生化难降解有机物的含量.     

Experimental study on oxidative decomposition of nitrobenzene in aqueous solution by honeycomb ceramic-catalyzed ozonation

The ozonation of nitrobenzene in aqueous solution was carried out in a semi-batch reactor to investigate the degradation efficiency, the effect factors, and the reaction mechanism, where honeycomb ceramic was used as a catalyst. The presence of honeycomb ceramic could improve the degradation rate of nitrobenzene by 15.46% compared to the results of ozonation alone. Under the conditions of this experiment, the degradation rate of honeycomb ceramic-catalyzed ozonation increased by 12.94% with the increase of the amount of catalyst from 1 to 5 blocks. The degradation rates all increased greatly with the increase of temperature and pH of the solution in the processes of honeycomb ceramiccatalyzed ozonation and ozonation alone. But, when the pH of the solution increased to 9.50, the advantage of the honeycomb ceramic-catalyzed ozonation process would be lost. The experimental findings indicated that in the processes of ozonation alone and honeycomb ceramic-catalyzed ozonation, nitrobenzene was primarily oxidized by ·OH free radical in aqueous solution. The adsorption of nitrobenzene was too limited to have an important influence on the degradation rate of nitrobenzene. With the same total dosage of applied ozone, the multiple step addition of ozone showed much higher removal efficiency than that obtained by one step in the two processes.     

Impacts of advanced treatment processes on elimination of antibiotic resistance genes in a municipal wastewater treatment plant

The distributions of ARGs were monitored in a WWTP in Harbin during six months. CASS had the best removal efficacy of ARGs compared to other processes in the WWTP. UV disinfection could effectively control the HGT. AGAC significantly remove ARGs and organics due to its high absorption capacity. Combination of ozone and AGAC significantly improve removal of ARGs and organics. Antibiotic resistance genes (ARGs) pose a serious threat to public health. Wastewater treatment plants (WWTPs) are essential for controlling the release of ARGs into the environment. This study investigated ARG distribution at every step in the treatment process of a municipal WWTP located in Harbin for six consecutive months. Changes in ARG distribution involved in two advanced secondary effluent treatment processes, ozonation and granular activated carbon (GAC) adsorption, were analyzed. Biological treatment resulted in the highest ARG removal (0.76–1.94 log reduction), followed by ultraviolet (UV) disinfection (less than 0.5-log reduction). Primary treatment could not significantly remove ARGs. ARG removal efficiency increased with an increase in the ozone dose below 40 mg/L. However, amorphous GAC (AGAC) adsorption with a hydraulic retention time (HRT) of 1 h showed better removal of ARGs, total organic carbon (TOC), total nitrogen (TN), and total phosphorus (TP) than ozonation at a 60 mg/L dose. UV treatment could efficiently reduce the relative ARG abundance, despite presenting the lowest efficiency for the reduction of absolute ARG abundance compared with GAC and ozone treatments. The combination of ozone and AGAC can significantly improve the removal of ARGs, TOC, TN and TP. These results indicate that a treatment including biological processing, ozonation, and AGAC adsorption is a promising strategy for removing ARGs and refractory organic substances from sewage.     

Characterization of natural organic matters effect on the biodegradation in the slow sand filter

This study focuses on the differences in biodegradation of the natural organic matters (NOMs) of p-hydroxy-benzoic acid (PHBA) and 4-hydroxy-3-methoxy-benzoic acid (VA) with slow sand filter (SSF). The PHBA and VA were biologically transformed into another organic matter in the slow sand filtration (SSF) at the start-up period. The dissolved organic carbon (DOC) of PHBA and VA were stabilized at 2 mg/l after 5th day. The SUVA value of PHBA run decreased with higher sand depth and flow rate, and VA run's increased with higher sand depth, but smaller than PHBA run. Therefore, the PHBA promoted the DBPFP (formation potential of disinfection by products), the VA brought higher biodegradation and lower DBPFP.     

给水深度处理中臭氧副产物的产生及控制

就给水深度处理中臭氧副产物的产生及其化学过程、控制臭氧副产物生成的技术措施等问题进行了探讨。采用臭氧深度处理时,会产生以甲醛为代表的有机副产物,以溴酸根为代表的无机副产物。副产物的形成与溴离子浓度、水中有机物种类和浓度、pH值、臭氧投加量、温度和碱度等因素有关。在应用臭氧进行深度处理时,应根据不同条件,采取适宜的措施,以减少臭氧副产物的生成。     

Characteristics and removal mechanism of the precursors of N-chloro-2,2-dichloroacetamide in a drinking water treatment process at Taihu Lake

• N-Cl-DCAM, an emerging N-DBP in drinking water was investigated. • A new BAC has a better removal efficiency for N-Cl-DCAM precursors than an old BAC. • N-Cl-DCAM precursors are more of low molecular weight and non-polar. • Adsorption of GAC plays a major role in removal of N-Cl-DCAM precursors by an O₃-BAC. N-chloro-2,2-dichloroacetamide (N-Cl-DCAM) is an emerging nitrogenous disinfection by-product (N-DBP) which can occur in drinking water. In this study, an analytical method based on liquid chromatography with tandem mass spectrometry (LC-MS/MS) was developed to validate the concentration of N-Cl-DCAM, which was found to be 1.5 mg/L in the effluent of a waterworks receiving raw water from Taihu Lake, China. The changes of N-Cl-DCAM formation potential (N-Cl-DCAMFP) in the drinking water treatment process and the removal efficiency of its precursors in each unit were evaluated. Non-polar organics accounted for the majority of N-Cl-DCAM precursors, accounting for 70% of the N-Cl-DCAM FP. The effect of conventional water treatment processes on the removal of N-Cl-DCAM precursors was found to be unsatisfactory due to their poor performance in the removal of low molecular weight (MW) or non-polar organics. In the ozonation integrated with biological activated carbon (O₃-BAC) process, the ozonation had little influence on the decrease of N-Cl-DCAM FP. The removal efficiency of precursors by a new BAC filter, in which the granular activated carbon (GAC) had only been used for four months was higher than that achieved by an old BAC filter in which the GAC had been used for two years. The different removal efficiencies of precursors were mainly due to the different adsorption capacities of GAC for individual precursors. Low MW or non-polar organics were predominantly removed by GAC, rather than biodegradation by microorganisms attached to GAC particles.     

大清河人工快速渗滤系统示范工程效果分析

以滇池流域受污染的大清河为研究对象,开展了人工快速渗滤系统（CRI）示范工程研究,根据气候条件、进水水质和运行工艺分为6个工况,以探索污染负荷和工艺参数对CRI运行性能的影响。实验结果表明：水力负荷2 m.d-1、湿干比1：1是该示范工程运行的最优工艺条件。CRI系统对有机物（COD）的平均去除率范围17.42%～63.75%;对氨氮去除效果受进水水质影响,高、低污染负荷下NH3-N去除率分别为56.71%、85.48%;CRI示范工程硝化作用较强,反硝化能力较弱,对TN的平均去除率范围为10.69%～28.29%;CRI示范工程对TP的平均去除率为27.62%,最佳工艺条件下为50.23%。CRI系统可通过对填料进行优化组合、适当增大饱水带高度,强化除磷脱氮能力。     

Degradation of endocrine disruptor bisphenol A in drinking water by ozone oxidation

The ozone oxidation of endocrine disruptor bisphenol A in drinking water was investigated. A stainless completely mixed reactor was employed to carry out the degradation experiments by means of a batch model. With an initial concentration of 11.0 mg/L, the removal efficiencies of BPA (bisphenol A) could be measured up to 70%, 82%, and 90% when the dosages of ozone were 1, 1.5, and 2 mg/L, respectively. The impacts on BPA degradation under the conditions of different ozone dosages, water background values, BPA initial concentrations, and ozone adding time were analyzed. The results showed that ozone dosage plays a dominant role during the process of BPA degradation, while the impact of the contact time could be ignored. UV wavelength scanning was used to confirm that the by-products were produced, which could be absorbed at UV254. The value of UV254 was observed to have changed during the ozonation process. Based on the change of UV254, it could be concluded that BPA is not completely degraded at low ozone dosage, while shorter adding time of total ozone dosage, high ozone dosage, and improvement of dissolved ozone concentration greatly contribute to the extent of BPA degradation. The effects of applied H₂O₂ dose in ozone oxidation of BPA were also examined in this study. The O₃-H₂O₂ processes proved to have similar effects on the degradation of BPA by ozone oxidation.     

Pathway of the ozonation of 2,4,6-trichlorophenol in aqueous solution

The reaction mechanism and pathway of the ozonation of 2,4,6-trichlorophenol (2,4,6-TCP) in aqueous solution were investigated. The removal efficiency and the variation of H₂O₂, Cl^? formic acid, and oxalic acid were studied during the semi-batch ozonation experiments (continuous for ozone gas supply, fixed volume of water sample). The results showed that when there was no scavenger, the removal efficiency of 0.1 mmol/L 2,4,6-TCP could reach 99% within 6 min by adding 24 mg/L ozone. The reaction of molecular ozone with 2,4,6-TCP resulted in the formation of H₂O₂. The maximal concentration of H₂O₂ detected during the ozonation could reach 22.5% of the original concentration of 2,4,6-TCP. The reaction of ozone with H₂O₂ resulted in the generation of a lot of OH? radicals. Therefore, 2,4,6-TCP was degraded to formic acid and oxalic acid by ozone and OH? radicals together. With the inhibition of OH? radicals, ozone molecule firstly degraded 2,4,6-TCP to form chlorinated quinone, which was subsequently oxidized to formic acid and oxalic acid. Two reaction pathways of the degradation of 2,4,6-TCP by ozone and O₃/OH? were proposed in this study.     

潜流人工湿地中有机污染物降解机理研究综述

人工湿地是一种完整的生态系统,它是利用系统中发生的物理、化学和生物等多重协同作用实现对污水的净化功能.开展潜流人工湿地中废水处理的机理、湿地内部有机污染物的迁移转化、湿地工艺设计及其水力学、动力学参数的研究,对环境废水中有机污染物的去除及生态安全具有重要意义.文章主要从化学、生物、设计参数等方面论述了人工湿地废水处理中有机污染物的降解及其机理研究进展.化学因素主要包括溶解性有机质(DOM)对有机污染物的迁移转化、氧化还原环境(Redox)及废水中电子受体的存在对有机质的分解状况、不同溶解氧(DO)水平为厌氧、好氧细菌对有机物的生物降解及湿地内反应动力学模型建立等因素对废水中有机污染物降解的作用及影响;生物因素主要涉及植物和微生物的作用,湿地中的生物降解是有机污染物的主要去除方式;在工艺参数方面,主要就水流特性、孔隙度、停留时间(HRT)、水力负荷(HLR)和水位等因素对湿地中有机污染物去除的影响进行了探讨.     

ZnO-MgO/Al2O3吸附-臭氧催化氧化处理难降解有机废水

以活性氧化铝为载体,采用浸渍法制备催化剂,对甲基橙及草酸模拟废水进行处理.在中性条件下,臭氧催化氧化比单独臭氧氧化能提前30 min使得甲基橙溶液褪色,反应105 min时,臭氧催化氧化对TOC的去除率高达96.53%,比单独使用臭氧氧化对甲基橙TOC去除率提高了47.19%,在处理草酸废水时臭氧催化氧化对TOC去除率高达80.59%,比单独使用臭氧氧化对草酸TOC去除率提高了59.14%.在处理甲基橙及草酸的小试实验中催化剂对有机污染物的吸附作用起到了加快反应进行的作用.在对垃圾渗滤液超滤出水时,O₃与COD质量比为1:1时,臭氧催化氧化对COD去除率为49.09%,比单独使用臭氧氧化提高36.37%,臭氧催化氧化对TOC的去除率是单独使用臭氧氧化的2.54倍,在处理垃圾渗滤液纳滤浓水时,臭氧催化氧化对COD去除率高达88.72%,比单独使用臭氧氧化提高37.60%,并且臭氧催化氧化对TOC的去除率是单独臭氧氧化的1.6倍.臭氧催化氧化反应过程中产生的羟基自由基对有机物更快的反应速率.     

Removal efficiencies of natural and synthetic progesterones in hospital wastewater treated by different disinfection processes

● The concentrations of 61 progesterones in HWW, PFTE, SBTE were evaluated. ● The removal efficiencies of progesterones by PFT and SBT were identified. ● Compared the removal efficiencies of progeste rones in five disinfection processes. Progesterones are ubiquitous in hospital wastewater (HWW) with concentrations much higher than those of estrogens and androgens. To ensure that these water systems are safe to use, disinfection is crucial during HWW treatment by providing “front line” defense against biological contaminations. Here, five disinfection processes, namely, chlorine (Cl₂), chlorine dioxide (ClO₂), ozone (O₃), ultraviolet (UV)), and UV/chlorine (UV/Cl₂), were selected to investigate their removal efficiencies for progesterones in primary filtration and secondary biological treatment effluents. There were 61 natural and synthetic progesterones detected in HWW, with the natural progesterones being the main components with a concentration of 845.51 ng/L and contributing to 75.08% of the total progesterones. The primary filtration treatment presented insignificant removal effects on the progesterones, while the secondary biological treatment significantly reduced the progesterone content by biodegradation. The order of removal efficiencies of total progesterones by different disinfection processes was UV/Cl₂ > Cl ₂ > O ₃ > ClO ₂ > UV. UV/Cl ₂ showed the highest removal efficiency against progesterones mainly due to the activation of Cl₂ by ultraviolet (UV) photolysis, which helps open the heterocyclic, aromatic, and phenolic rings, thus accelerating progesterone degradation. In addition, the removal efficiencies of natural progesterones in the five disinfection processes were higher than those of synthetic progesterones (progesterone derivatives, 19-nortestosterone derivatives, and 17α-hydroxyprogesterone derivatives).     

腐植酸臭氧氧化和过氧化氢催化氧化处理特性比较

以TOC和UV254为指标,比较了不同条件下腐植酸的臭氧氧化和过氧化氢催化氧化效果,运用HPLC和热裂解-GC-MS分析考察了氧化前后有机物分子量分布和官能团构造的变化情况．研究结果表明：过氧化氢和臭氧单独作为氧化剂对水中TOC基本上没有去除作用,但均能导致水中UV254浓度的降低;在几种催化剂的作用下,过氧化氢对TOC和UV254的去除效果明显提高,其中以O3作为催化剂的效果最好,Fe^2＋次之,而Mn^2＋和Cu^2＋的催化效果较差;过氧化氢催化氧化和臭氧化均导致有机物分子量分布向小分子的方向转移,氧化后水中以羧酸、醇、胺、酯、醚、烷烃为代表的含氧基团和饱和构造基团明显增多;过氧化氢催化氧化和臭氧氧化均有助于改善混凝处理和活性炭吸附处理的效果．关键词腐植酸,臭氧,过氧化氢,催化氧化．     

Remediation of Kraft E1 and black liquor effluents by biological and chemical processes

We sutdied the application of the bacteria Azotobacter vinellandi on the treatment of effluents from pulp and paper industry. Two types of treatment employing this microorganism were studied: biological treatment isolated and combined with stages of pre- or post-treatment using ozonation or photocatalysis processes. In the biological treatment, the siderophores production by A. vinellandi had a major effect on the efficiency of effluents degradation. Among the different combined treatments, the best results were obtained with the photocatalytic pre-treatment.     

Catalytic activity of cerium-doped Ru/AlO during ozonation of dimethyl phthalate

In this paper, factors influencing the mineralization of dimethyl phthalate (DMP) during catalytic ozonation with a cerium-doped Ru/Al₂O₃ catalyst were studied. The catalytic contribution was calculated through the results of a comparison experiment. It showed that doping cerium significantly enhanced catalytic activity. The total organic carbon (TOC) removal over the doped catalyst at 100 min reached 75.1%, 61.3% using Ru/Al₂O₃ catalyst and only 14.0% using ozone alone. Catalytic activity reached the maximum when 0.2% of ruthenium and 1.0% of cerium were simultaneously loaded onto Al₂O₃ support. Results of experiments on oxidation by ozone alone, adsorption of the catalyst, Ce ion’s and heterogeneous catalytic ozonation confirmed that the contribution of heterogeneous catalytic ozonation was about 50%, which showed the obvious effect of Ru–Ce/Al₂O₃ on catalytic activity.     

Catalytic ozonation of organic compounds in water over the catalyst of RuO2/ZrO2-CeO2

This research investigates the performances of RuO₂/ZrO₂-CeO₂ in catalytic ozonation for water treatment. The results show that RuO₂/ZrO₂-CeO₂ was active for the catalytic ozonation of oxalic acid and possessed higher stability than RuO₂/Al₂O₃ and Ru/AC. In the catalytic ozonation of dimethyl phthalate (DMP), RuO₂/ZrO₂-CeO₂ did not enhance the DMP degradation rate but significantly improved the total organic carbon (TOC) removal rate. The TOC removal in catalytic ozonation was 56% more than that in noncatalytic ozonation. However this does not mean the catalyst was very active because the contribution of catalysis to the overall TOC removal was only 30%. The adsorption of the intermediates on RuO₂/ZrO₂-CeO₂ played an important role on the overall TOC removal while the adsorption of DMP on it was negligible. This adsorption difference was due to their different ozonation rates. In the catalytic ozonation of disinfection byproduct precursors with RuO₂/ZrO₂-CeO₂, the reductions of the haloacetic acid and trihalomethane formation potentials (HAAFPs and THMFPs) for the natural water samples were 38%–57% and 50%–64%, respectively. The catalyst significantly promoted the reduction of HAAFPs but insignificantly improved the reduction of THMFPs as ozone reacts fast with the THMs precursors. These results illustrate the good promise of RuO₂/ZrO₂-CeO₂ in catalytic ozonation for water treatment.     

Optimization of the O3/H2O2 process with response surface methodology for pretreatment of mother liquor of gas field wastewater

• Real ML-GFW with high salinity and high organics was degraded by O₃/H₂O₂ process. • Successful optimization of operation conditions was attained using RSM based on CCD. • Single-factor experiments in advance ensured optimal experimental conditions. • The satisfactory removal efficiency of TOC was achieved in spite of high salinity. • The initial pH plays the most significant role in the degradation of ML-GFW. The present study reports the use of the O₃/H₂O₂ process in the pretreatment of the mother liquor of gas field wastewater (ML-GFW), obtained from the multi-effect distillation treatment of the gas field wastewater. The range of optimal operation conditions was obtained by single-factor experiments. Response surface methodology (RSM) based on the central composite design (CCD) was used for the optimization procedure. A regression model with Total organic carbon (TOC) removal efficiency as the response value was established (R² = 0.9865). The three key factors were arranged according to their significance as: pH>H₂O₂ dosage>ozone flow rate. The model predicted that the best operation conditions could be obtained at a pH of 10.9, an ozone flow rate of 0.8 L/min, and H₂O₂ dosage of 6.2 mL. The dosing ratio of ozone was calculated to be 9.84 mg O₃/mg TOC. The maximum removal efficiency predicted was 75.9%, while the measured value was 72.3%. The relative deviation was found to be in an acceptable range. The ozone utilization and free radical quenching experiments showed that the addition of H₂O₂ promoted the decomposition of ozone to produce hydroxyl radicals (·OH). This also improved the ozone utilization efficiency. Gas chromatography-mass spectrometry (GC-MS) analysis showed that most of the organic matters in ML-GFW were degraded, while some residuals needed further treatment. This study provided the data and the necessary technical supports for further research on the treatment of ML-GFW.     

Catalytic activity of cerium-doped Ru/Al2O3 during ozonation of dimethyl phthalate

In this paper, factors influencing the mineralization of dimethyl phthalate (DMP) during catalytic ozonation with a cerium-doped Ru/Al₂O₃ catalyst were studied. The catalytic contribution was calculated through the results of a comparison experiment. It showed that doping cerium significantly enhanced catalytic activity. The total organic carbon (TOC) removal over the doped catalyst at 100 min reached 75.1%, 61.3% using Ru/Al₂O₃ catalyst and only 14.0% using ozone alone. Catalytic activity reached the maximum when 0.2% of ruthenium and 1.0% of cerium were simultaneously loaded onto Al₂O₃ support. Results of experiments on oxidation by ozone alone, adsorption of the catalyst, Ce ion’s and heterogeneous catalytic ozonation confirmed that the contribution of heterogeneous catalytic ozonation was about 50%, which showed the obvious effect of Ru-Ce/Al₂O₃ on catalytic activity.     

Kinetic studies of the degradation of parabens in aqueous solution by ozone oxidation

Ozone degradation of a mixture containing methylparaben, ethylparaben, propylparaben, butylparaben and benzylparaben was carried out in aqueous solution. The degradation followed the pseudo-first-order kinetic model and occurs with two ozonation stages with the observed rate constants of second stage ozonation, k _obs2, being higher than the observed rate constants in first stage, k _obs1. The k _obs1 of parabens was found to increase exponentially whilst k _obs2 was found to maximize at 35°C. Both k _obs1 and k _obs2 were found to decrease exponentially with respect to the initial concentration of parabens. Both pH and ozone dose showed positive effects on the rate of degradation. It was also observed that an ozone dose of 0.67 g/h resulted in the removal of 99% of parabens in 12 min, and also the removal of 61 and 32% of chemical oxygen demand (COD) and total organic carbon (TOC), respectively, in 3 h of ozonation time for a 500 μM of solution of parabens.     

Significant increase of assimilable organic carbon (AOC) levels in MBR effluents followed by coagulation,ozonation and combined treatments: Implications for biostability control of reclaimed water

• Annual AOCs in MBR effluents were stable with small increase in warmer seasons. • Significant increase in AOC levels of tertiary effluents were observed. • Coagulation in prior to ozonation can reduce AOC formation in tertiary treatment. • ∆UV₂₅₄ and SUVA can be surrogates to predict the AOC changes during ozonation. As water reuse development has increased, biological stability issues associated with reclaimed water have gained attention. This study evaluated assimilable organic carbon (AOC) in effluents from a full-scale membrane biological reactor (MBR) plant and found that they were generally stable over one year (125–216 µg/L), with slight increases in warmer seasons. After additional tertiary treatments, the largest increases in absolute and specific AOCs were detected during ozonation, followed by coagulation-ozonation and coagulation. Moreover, UV₂₅₄ absorbance is known to be an effective surrogate to predict the AOC changes during ozonation. Applying coagulation prior to ozonation of MBR effluents for removal of large molecules was found to reduce the AOC formation compared with ozonation treatment alone. Finally, the results revealed that attention should be paid to seasonal variations in influent and organic fraction changes during treatment to enable sustainable water reuse.