磁性活性炭活化S2O82-在焦化废水深度处理中的应用

采用磁性活性炭(Cu Fe2O4/AC,MACC)活化S_2O_8~(2-)深度处理焦化废水生化出水,考察了m(Cu Fe2O4)∶m(AC)、MACC投加量、K_2S_2O_8初始质量浓度以及溶液pH对焦化废水生化出水中TOC和色度去除效果的影响,并采用响应面法中的CCD实验设计对反应条件进行优化。结果表明:最佳反应条件为1.5-MACC投加量为5 g/L,K_2S_2O_8初始质量浓度为6 g/L和初始pH为8.3,在此条件下反应360 min后,TOC、色度去除率分别为85.4%、95.2%。响应面分析结果表明,最佳条件下的TOC去除率与模型预测值接近。     

O3催化氧化法去除焦化废水中的污染物

采用O3催化氧化法去除焦化废水中经生物处理后的残余污染物,考察了气相中O3浓度、气体流速、金属离子催化的影响.结果发现,在O3分子的直接氧化下,TOC去除率较差,废水的脱色时间为120min左右;在Cu2 、Co2 、Fe2 、Mn2 等金属离子催化氧化下,废水的脱色时间缩短至60min,出水接近无色.     

焦化废水深度处理技术综述

焦化废水是煤焦化过程产生的废水,含有高浓度的酚类、苯系物、杂环化合物、多环化合物等有机污染物,并且高盐、高氨氮,是一类难处理的工业废水。随着国家对焦化废水的管理日趋严格,传统的"预处理+生化处理"工艺很难满足排放或回用要求,因此对焦化废水的深度处理势在必行。从物化法和生化法两个方面对目前焦化废水深度处理常用技术的研究和应用情况进行了介绍,并探索性地提出了焦化废水深度处理技术未来的研究和发展方向。     

焦化废水深度处理研究进展

焦化废水含有大量有机污染物和有毒无机物,成分复杂,污染物色度高,属较难生化降解的高浓度有机工业废水.经常规方法预处理,再经生化处理后的焦化废水存在氰化物、COD及氨氮等不达标的问题.通过臭氧氧化法、Feton试剂氧化法以及光催化氧化法等高级氧化法,活性炭以及矿物吸附法等三级深度处理可以解决这一问题.介绍了目前焦化废水深度处理的研究进展并进行了展望.     

树脂吸附法对焦化废水的深度处理

介绍了焦化废水生化后尾水的深度处理工程实例。针对生化尾水的特点,选择了斜管沉淀、浅层介质过滤和树脂吸附的组合处理工艺,处理后尾水的色度、总氰化物、悬浮物的去除率分别达到89.7%、88.1%和69.6%,排水指标优于《炼焦化学工业污染物排放标准》(GB 16171—2012)中的要求,具有较好的应用前景。     

A2O工艺去除焦化废水中挥发性有机物的研究

用厌氧-缺氧-好氧（A2O）工艺处理焦化废水,研究探讨A2O工艺处理焦化废水各工艺段对挥发性有机物的生物降解和去除规律。采用GC—MS联用技术对焦化废水中的挥发性有机物进行定性定量分析,共检测各类挥发性有机物18种。     

A2/O法处理焦化废水

总结了AVO法处理焦化废水的一个实例。实践证明,AVO法处理焦化废水是可行的,关键是在好氧段中要培养出足够的硝化细菌。工程实际运行结果表明,该系统运行稳定,出水中的酚、氰、CODcr和NH3-N等指标均达到国家标准。酚由400mg／L降到0．5mg／L以下,氰由4mg／L降到0．5mg／L以下,CODcr值由3000mg／L降到150mg／L以下,NH3-N由70mg／L降到15mg／L以下。废水处理量为260m^3／h。     

焦化废水常用处理工艺的研究进展

焦化废水是一种典型的盐分多态化、氮磷营养失衡、高毒性的复杂工业废水,处理工艺长且难度大。文章在总结焦化废水预处理、生物处理的基础上,分析了混凝沉淀、吸附、MBR、膜分离等深度处理技术的优缺点、作用机理和发展前景,并重点对高级氧化技术进行了具体阐述。膜技术作为深度处理的最后一道工艺,在焦化废水的回用方面必不可少;对传统生化技术进行改进的同时,采用多级生化、物化处理技术是未来焦化废水处理的发展方向。     

O1/A/O2工艺处理高浓度焦化废水

焦化废水水质复杂,处理难点在于去除水中高浓度的CODCr、NH3-N和氰化物等。首钢某焦化厂废水处理工程采用以O1/A/O2工艺(预曝气/缺氧/好氧)为核心、前置除油预处理、后置混凝沉淀深度处理工艺,取得了较好的处理效果。运行结果表明:O1/A/O2工艺对CODCr和NH3-N的去除率分别可达95%和89%以上;混凝沉淀采用聚合硫酸铁絮凝剂和PAM助凝剂,加药量分别为600~800 mg/L和1~2 mg/L时,CODCr去除率在50%左右,脱色效果好。经过预处理、生化处理及深度处理后,出水主要污染物指标达到了《污水综合排放标准》的二级排放标准要求。     

Fenton高级氧化法深度处理焦化生化废水的实验研究

采用硫酸亚铁和过氧化氢所构成的Fenton试剂,对经生化处理后的焦化废水进行Fenton高级氧化深度处理,重点考察了废水初始pH,FeSO4·7H2O、H2O2及PAM投加量对焦化生化废水处理效果的影响。结果表明,采用Fenton高级氧化法可使经生化处理后的焦化废水中的COD、NH3-N和色度得到进一步有效去除。对于中等浓度的焦化生化废水,较适宜的Fenton氧化工艺条件:废水初始pH为8~10,FeSO4·7H2O投加量为500 mg/L,H2O2投加量为3.5 mL/L,PAM投加量为4.0 mg/L。在此条件下,COD、NH3-N和色度的去除率分别可达85.9%、97.3%和84.6%。     

双膜法与树脂吸附组合工艺在焦化废水深度处理上的应用

经过AAO脱氮处理后的焦化废水仍然含有较高浓度的悬浮物、CODCr、NH3-N、Cl-、溶解性固体等,采用超滤-树脂吸附-反渗透组合工艺处理该废水,不仅使出水水质达到GB 50050—2007《工业循环冷却水处理设计规范》中的回用水标准的要求,而且能够较好地解决单一双膜法膜元件易污堵、清洗频繁的问题。介绍了处理工艺的流程及其选择说明,给出了主要建筑物的设计参数及经济分析,该工艺处理成本约为5.98元/m3。     

UV-H2O2工艺对焦化废水中氰化物深度处理研究

在新颁布的《炼焦化学工业污染物排放标准》(GB 16171—2012)中,总氰化物的排放限值降至0.2 mg/L,这使得传统除氰工艺已无法满足处理要求。以某焦化厂经生化、混凝处理后的出水为研究对象,探究了UV-H2O2工艺用于深度除氰的可行性。实验结果表明:在p H=10、n(H2O2)∶n(CN)=250∶1的条件下,UV-H2O2工艺处理30 min后总氰去除率可达80%,出水总氰(<0.18 mg/L)满足新标准要求。     

焦化废水膜法组合深度处理工艺设计与应用

针对煤化工企业焦化废水的二级生化出水可生化性差、含盐量与COD高,以及废水中包含多环芳香族化合物、脂肪族化合物等难生物降解污染物的特点,采用Fenton氧化+电渗析+超滤+反渗透膜法组合深度处理工艺对废水进行处理。运行结果表明,产水水质达到并优于《工业循环冷却水处理设计规范》(GB 50050—2007)中再生水水质要求,产水可作为厂区生产补充新水使用,废水回收率稳定达到75%。采用Fenton氧化与电渗析粗脱盐技术相结合的强化预处理设施,可以有效缓解反渗透装置的膜污染,延长反渗透膜的清洗周期至3个月。     

O3/H2O2组合工艺处理丁苯橡胶生产废水的研究

针对合成橡胶生产废水,特别是丁苯橡胶(SBR)生产废水的悬浮物浓度高,成分复杂,可生化性差,难以达到国家排放标准等问题,以O3/H2O2组合工艺对SBR生产废水进行非均相催化氧化处理实验,探讨了影响COD去除率的各种因素,确定了最佳的混凝和催化氧化条件.研究结果表明:采用混凝-催化氧化工艺可使原水的COD从860 mg/L降至145 mg/L,去除率83.1%,出水达到国家二级排放标准.     

A compact process for the treatment of olive mill wastewater by combining OF and UV/H2O2 techniques

Olive oil production results in important quantities of wastewater containing large amounts of total solids and organic carbon as well as low oil concentrations. This paper describes the treatment of olive mill wastewater (OMW) by combining an ultrafiltration (UF) technique and an advanced oxidation process (AOP) using UV/H₂O₂. It further demonstrates the technical feasibility of this compact and stable process to remove a large part of total solids and organic carbon. Indeed, OF reduces the pollutants contained in the OMW with an apparent rejection coefficient R_COD in the range of 94%. The UV/H₂O₂ oxidation process may be easily used, in combination with UF, to finish the treatment of the permeate. The results obtained in batch and continuous mode showed that this technique offered a treated solution which complies with legal requirements. A final concentration of 17 mg_TOC dm⁻³ was obtained, which corresponds to a final COD of 52 mg dm⁻³, while the legal requirement is 125. Furthermore, the final effluent is fully decolorized.     

Removal of NO from flue gas using UV/S2 process in a novel photochemical impinging stream reactor

A novel photochemical impinging stream reactor was developed for the first time. Removal process of NO from flue gas using sulfate radical ( ·) and hydroxyl radical (·OH) from UV‐light activation of persulfate (UV/S₂ advanced oxidation process) was investigated in the novel reactor. Experiments were conducted to evaluate the effects of S₂ concentration, solution pH, UV power, solution temperature, liquid‐gas ratio, flue gas flow, NO, SO₂,and O₂ concentrations on removal of NO. Mechanism and kinetics of NO removal were also studied. The results show that increasing UV power, solution temperature, S₂ concentration, or solution circulation rate promotes NO removal. Increasing solution pH (1.2–11.9), NO concentration or flue gas flow weakens NO removal. O₂ concentration has no significant effect on NO removal. · and ·OH were the major active species for NO removal. Absorption rate equation and kinetic parameters of NO removal were obtained. © 2017 American Institute of Chemical Engineers AIChE J, 63: 2968–2980, 2017     

A comparative study on the performance of different advanced oxidation processes (UV/O3/H2O2) treating linear alkyl benzene (LAB) production plant's wastewater

A detailed investigation on photooxidation of linear alkyl benzene (LAB) industrial wastewater is presented in this study. The process analysis was performed by varying four significant independent variables including two numerical factors (initial pH (3–11) and initial H₂O₂ concentration (0–20 mM)) and two categorical factors (UV irradiation and ozonation). The experiments were conducted based on a central composite design (CCD) and analyzed using response surface methodology (RSM). To assess the process performance, two parameters viz. TCOD removal efficiency and BOD₅/COD were measured throughout the experiments. A maximum reduction in TCOD was 58, 53, 51, and 49%, respectively for UV/H₂O₂/O₃, H₂O₂/O₃, UV/O₃ and UV/H₂O₂ processes at the optimum conditions (initial pH of 7, initial H₂O₂ concentration of 100 mM, and reaction time of 180 min). A considerable increase in BOD₅/COD ratio was obtained in the combined processes (0.46, 0.51, 0.53, and 0.55 for UV/H₂O₂, UV/O₃, H₂O₂/O₃ and UV/H₂O₂/O₃, respectively) compared to the single oxidant process (0.35). The results showed that mineralization of the LAB industrial wastewater in neutral pH is more favored than in acidic and basic pH. Gas chromatography–mass spectrometry (GC–MS) was applied to show the fate of organic compounds. In conclusion, the photooxidation process (UV/H₂O₂/O₃, H₂O₂/O₃, UV/O₃ and UV/H₂O₂) could be an appropriate pretreatment method prior to a biological treatment process.     

Oxidation of benzothiazole, 2‐mercaptobenzothiazole and 2‐hydroxybenzothiazole in aqueous solution by means of H2O2/UV or photoassisted Fenton systems

Oxidative treatments of benzothiazole and benzothiazole derivatives (2‐mercaptobenzothiazole, 2‐hydroxybenzothiazole) in aqueous solution have been studied by using H₂O₂/UV and iron(III) photoassisted Fenton techniques. Experimental runs have been carried out in the pH range 3.0 –8.0 by means of annular reactors and proper UV lamps. The effect of pH, the initial concentration of hydrogen peroxide, the substrate, and the iron(III) concentrations have been investigated. A suitable model has been developed and used for the best estimation of kinetic constants for HO radical attack on the target molecules with the H₂O₂/UV system. The values obtained with this model are consistent with those reported in the literature for other heterocyclic compounds. © 2001 Society of Chemical Industry