次氯酸钠处理水煤气废水中的氧化还原电位变化研究

介绍了利用次氯酸钠的强氧化作用来处理含硫水煤气废水。NaClO与水中S^2-等还原性物质的反应为典型的氧化还原反应,随着S^2-的被氧化,其氧化还原电位是变化的。针对这点,本文主要研究NaClO的投加量对S^2-氧化还原电位的影响,并以此来控制实际工程中NaClO的投加量,防止NaClO的过量投加带来对设备的腐蚀和对水煤气质量的影响。     

常用氧化剂性能研究

用四种常用的氧化剂:高锰酸钾、漂白粉、NaClO和H2O2/Fe2+对大港油田港深11井酸化废水进行了处理。考察了氧化剂的投加量、氧化时间和pH值对酸化废水色度和COD去除率的影响。实验结果表明,在最佳条件下,H2O2/Fe2+对酸化废水的色度和COD的去除率最高;用高锰酸钾处理废水,其COD去除率较高,但脱色效果差;而漂白粉和NaClO的脱色率较高,但其氧化能力有限。建议油田用氧化法处理废水时应采用H2O2/Fe2+催化氧化体系。     

Fenton氧化工艺处理DNT废水研究

DNT废水因其成分复杂、毒性大、难降解、对环境污染严重等特点,成为废水处理中的一个难题。本试验研究了难以生物降解DNT生产废水Fenton氧化处理效果,考查了各影响因子最佳工艺条件。结果表明,在pH值为2;FeSO4.7H2O投加量为200mg/L;H2O2投加量为2mL/L;反应时间为1h的条件下,Fenton氧化工艺COD去除率为47.76%,DNT去除率为87.37%左右。     

电解-耦合类芬顿催化氧化技术处理印染废水

采用电解-耦合类芬顿催化氧化技术对纺织印染行业废水进行深度处理,分别考察不同Fe/C比、溶液p H值、药剂投加量与反应时间对去除效果的影响,结果在p H值为3.5、Fe/C为1︰1、H_2O_2投加量为200mg/L、Fe SO_4投加量为200mg/L时,反应时间控制在20min,废水的COD去除率可达62.5%。     

催化氧化法在钻井废水处理中的应用

在油气田深井钻探过程中产生的钻井液,经固-液分离处理后产生的废水具有化学需氧量高、色度高、矿化度高、含油量高等特点,须进一步进行处理。采用Fenton试剂对钻井废水进行了催化氧化处理实验。结果表明,处理后, 废水中化学需氧量(COD)去除率可达82%,色度去除率为98.5%。H2O2/Fe2+投量摩尔比、H2O2/初始COD摩尔比、pH值和反应时间对废水COD、色度的去除率均有较大影响。用Fenton试剂催化氧化工艺处理聚磺体系钻井废水还具有处理效率高、操作简便、适用范围广等优点。     

絮凝-酸析-NaClO-Fenton联合处理页岩气产出水研究

以涪陵页岩气田产出水为研究对象，研究絮凝、酸析、Fenton氧化和NaClO氧化相互协同作用下，采出水COD去除率的变化程度及规律。比较了不同组合方式下水样COD去除效果及变化规律，考察了絮凝剂、次氯酸钠和Fenton试剂的加量以及体系pH值对去除率的影响，结果表明：（1）单一絮凝或酸析条件下，最高COD去除率＜25%，在絮凝剂加量80mg/L、酸析pH为4时，絮凝-酸析协同处理COD去除率达到＞40%；（2）原始水样直接进行次氯酸钠氧化，COD最高去除率为75.01%，絮凝-酸析后进行次氯酸钠氧化，最高COD去除率为80.34%，与原始水样相比提高了5.33%，且达到相同的COD去除效果，絮凝-酸析后水样对次氯酸钠的需求量低于原始水样；（3）絮凝-酸析后水样进行Fenton氧化与原始水样直接进行Fenton氧化相比，COD去除率提高了6.07%；（4）絮凝-酸析-NaClO- Fenton协同处理，水样COD去除率达到＞90%，其中最高去除为94.17%，与絮凝-酸析-NaClO和絮凝-酸析-Fenton处理相比分别提高了13.83%和5.27%。水样首先经过絮凝-酸析预处理，达到削减后续次氯酸钠和Fenton氧化负荷、降低药剂用量目的，然后经过Fenton试剂和次氯酸钠对不同类型特征污染物选择性去除的协同作用，可达到较高的COD去除率。     

气田压裂返排液氧化处理实验研究

以四川某气田压裂返排液为研究对象,采用破胶絮凝处理后进行氧化对比实验,氧化剂选用高锰酸钾、过硫酸钾、次氯酸钠、Fenton试剂。研究表明,絮凝实验最佳条件为氧化钙、硫酸铝和硫酸亚铁投加量分别为3,1,1 g/L。4种氧化方法的最佳实验条件为:高锰酸钾投加量0.5 g/L,pH值为4;过硫酸钾投加量0.25g/L,pH值为6;次氯酸钠投加量15 g/L,pH值为4;Fenton氧化方法pH值为3.5,双氧水投加量25 g/L,七水硫酸亚铁投加量10 g/L。出水COD_(Cr)最多可降至800 mg/L左右,最大COD_(Cr)去除率72.96%,处理效果良好,为后续处理创造了条件。     

纳米二氧化钛光催化氧化降解苯酚废水实验

开展实验室模拟苯酚废水的二氧化钛光催化氧化实验。结果表明：在苯酚废水曝气量为0～3L/min的条件下,随着曝气量的增大,COD去除率先增大后减小;初始浓度不变,光照时间为1h的条件下, 调节pH值在3～11,苯酚废水COD去除率随着pH值的增大而减小,当pH值为11时, COD去除率又开始增 大,酸性条件比碱性条件下COD去除率高;随着二氧化钛投加量的增加,COD去除率增大,当二氧化钛投加量 为10g/L时,COD去除率反而降低,二氧化钛最佳投加量为3g/L;随着苯酚废水初始浓度由75mg/L增加至300mg/L,COD去除率由78.2％降低到58.1％;反应温度的改变对COD和TOC的去除率没有影响。     

注空气低温氧化辅助热采废水处理

对注空气低温氧化辅助热采废水的处理进行实验研究,先进行混凝处理,再分别采用Fenton氧化法和二氧化氯氧化法对废水氧化处理。结果表明后者效果较好,二氧化氯最佳投加量为300 mg/L,催化剂活性炭-Ni投加量为2.5 g/L,反应2 h,COD_(Cr)降低至129.14 mg/L,去除率达到95.29%,出水无色透明。二氧化氯氧化法适合于海上油田注空气低温氧化辅助热采废水的处理。     

O2-Fenton试剂处理对氨基苯磺酸废水的探讨

利用由O2和Fenton试剂组成的类Fenton系统处理对氨基苯磺酸废水,取得了很好的降解效果.当FeSO4(10g/L)投加量为1.2mL、H2O2(3%)投加量为3mL时,COD去除率可达到70%.     

Application of lime and calcium hypochlorite in the dephenolisation and discolouration of olive mill wastewater

The application of hypochlorite for the removal of soluble COD, phenolic and polyphenolic like compounds, and other organic compounds responsible for the olive mill wastewater (OOWW) colour has been experimentally studied. After the OOWW filtration on a sand column, the effluent was subjected to a fast liming under optimal conditions. Lime application reduced polyphenols, COD and SS contents to half of their initial values but an important blackening of the treated OOWW was observed, especially when adding high concentrations of lime (10% (W/V) and 15% (W/V)).A second stage of treatment was applied using calcium hypochlorite. In this stage, removal of the studied compounds reached as much as 95% at higher concentrations, and particularly the colouring of OOWW which is generally difficult to eliminate was greatly reduced. The OOWW hypochloration acted through coagulation–flocculation and a rapid oxidation of the organic matter proceeded from the first 5 min. The kinetic study of the degradation of the waste polluting compounds from liming showed that Ca(ClO)₂ reacts similarly in the elimination of organic compounds, polyphenols, SS and colouration. The analysis of the organochloride compounds generated by the reaction between hypochlorite and the organic compounds showed that DDD, DDT and the heptachlor contents exceeded the values recommended by the International and European drinking water standards.     

Optimization of Fenton's oxidation of chemical laboratory wastewaters using the response surface methodology

Establishing a treatment process for practical and economic disposal of laboratory wastewaters has become an urgent environmental concern of the Department of Chemical Engineering of the Universidade Estadual de Maringá (State University of Maringá), Brazil. Fenton and related reactions are potentially useful oxidation processes for destroying toxic organic compounds in water. In these reactions, hydrogen peroxide is combined with ferrous or ferric iron in the presence or absence of light to generate hydroxyl radicals (.OH). The feasibility of Fenton's reagent to treat waste chemicals from an academic research laboratory was investigated in this study. A response surface methodology was applied to optimize the Fenton oxidation process conditions using chemical oxygen demand (COD) removal as the target parameter to optimize, and the reagent concentrations, as related to the initial concentration of organic matter in the effluent, and pH as the control factors to be optimized. Maximal COD removal (92.3%) was achieved when wastewater samples were treated at pH 4 in the presence of hydrogen peroxide and iron in the ratios [COD]:[H2O2]=1:9 and [H2O2]:[Fe2+]=4.5:1. Under these conditions, it was possible to obtain simultaneously maximal COD removal and minimal chemical sludge after treatment, which is a residue that needs further processing.     

絮凝- 电气浮法处理乳化油废水

含乳化油废水由于表面活性剂的存在处理难度较大。通过絮凝——电气浮方法处理乳化油废水,确定絮凝及絮凝——电气浮所需的最佳絮凝剂用量;通过正交试验考察了pH值、电流密度、电极间距及气浮时间等操作参数的影响,得到絮凝一电气浮的最优操作条件为电流密度为20．83A／m^2,电极间距为1cm,pH值为7．4。在聚合硫酸铁投加量为50mg／L,电气浮30min时COD去除率可达95．2％。此方法对轴承厂废水的COD去除率可达75％,出水COD可降至91．9mg／L。结果表明用这种方法处理乳化油废水是可行的。     

Electrocoagulation of vegetable oil refinery wastewater using aluminum electrodes

Electrocoagulation with aluminum electrodes was used to treat the vegetable oil refinery wastewater (VORW) in a batch reactor. The effects of operating parameters such as pH, current density, PAC (poly aluminum chloride) dosage and Na(2)SO(4) dosage on the removal of organics and COD removal efficiency have been investigated. It has been shown that the removal efficiency of COD increased with the increasing applied current density and increasing PAC and Na(2)SO(4) dosage and the most effective removal capacity was achieved at the pH 7. The results indicate that electrocoagulation is very efficient and able to achieve 98.9% COD removal in 90 min at 35 mAcm(-2) with a specific electrical energy consumption of 42 kWh(kgCOD(removed))(-1). The effluent was very clear and its quality exceeded the direct discharge standard.     

车载巡回式UV／Fenton装置处理小城镇垃圾渗滤液

为了研究车载巡回处理装置对小城镇垃圾渗滤液的处理效果,采用自制的UV-Fenton试验装置研究了pH值、FeSO_4剂量、反应时间等因素对处理效果的影响,结果表明:最佳pH值为4.0,进水中COD为825 mg/L时,FeSO_4和H_2O_2的投加量分别为0.008 mol/L和0.08 mol/L,此时COD去除率72.22%,出水COD为216 mg/L;随着FeSO_4投加量缓慢增加到一定程度后转而下降,FeSO_4最佳投加量为0.008 mol/L;不同H_2O_2和Fe~(2+)配比对COD去除效果具有影响,(10:1)时为最佳配比。经过氨吹脱和混凝沉淀预处理的渗滤液采用UV/Fenton处理工艺,出水中COD可以达到《生活垃圾填埋场污染控制标准》(GB 16889-1997)中二级标准。     

用二氧化钛光催化氧化法降低丙烯腈污水中的化学需氧量

在开放的光催化反应器中,以紫外(UV)光为光源,以二氧化钛为催化剂,研究了不同水质条件下对模拟丙烯腈(AN)污水中化学需氧量(COD)的控制效果及主要影响因素。结果表明,UV光-TiO2催化体系对AN污水中COD具有良好的去除效果。当在浓度为300mg/L模拟AN污水中投加浓度为20mg/L的二氧化钛及紫外光照射180min时,污水体系中的COD残存率为7.9%。同时,反应过程中不会对环境产生二次污染。     

不同酸对造纸黑液酸析效果的研究

采用酸析法从造纸黑液中分离木质素,同时去除部分COD和色度,从而完成对黑液的初步处理。实验研究了酸析的最佳pH值,并将硫酸、硝酸、盐酸、磷酸、甲酸和草酸作为酸析剂,分析其分别对黑液色度、COD的去除效果及对木质素提取的影响。介绍了通过快速消解分光光度法来测定COD值,和用分光光度法测定色度值,分别建立COD值和色度对吸光度的工作曲线,使测量更加方便高效快捷,其精确度和准确度都能符合分析方法要求。实验结果表明,酸析效果较好的pH取值范围为2～4,考虑用酸的经济性和处理效果,选择pH=3作为最佳酸析条件;经过对酸析过程规律和原因的分析可得,硫酸、硝酸和磷酸对黑液处理效果较为理想,其中硫酸因其经济性被选为最佳,其色度、COD去除率分别为97.9%和66.1%,木质素的析出量为8.65 g/L。     

颗粒活性炭载体新型生物转盘去除生活污水中COD和NH3-N的研究

开发一种改进型生物转盘处理生活污水,将盘片改为转笼状,并向其中加入颗粒活性发作为载体,研究该系统对生活污水的处理效果。结果表明：在转盘转速为15rpm和HRT分别为10h、8h、6h、4．5h情况下,进水COD平均浓度约为223mg／L,出水COD平均浓度分别为15．6、17．9、23．4、28．2mg/L,平均去除率为93．0％、91．9％、89．5％、86．6％;进水NH3-N平均浓度约为22mg／L,出水NH3-N平均浓度分别为0．32、1．13、2．30、5．71mg／L,平均去除率为98．5％、94．8％、89．7％、74．6％。     

Evaluation of Fenton and ozone-based advanced oxidation processes as mature landfill leachate pre-treatments

Fenton treatment (Fe²⁺/H₂O₂) and different ozone-based Advanced Oxidation Processes (AOPs) (O₃, O₃/OH⁻ and O₃/H₂O₂) were evaluated as pre-treatment of a mature landfill leachate, in order to improve the biodegradability of its recalcitrant organic matter for subsequent biological treatment. With a two-fold diluted leachate, at optimised experimental conditions (initial pH 3, H₂O₂ to Fe²⁺ molar ratio of 3, Fe²⁺ dosage of 4 mmol L⁻¹, and reaction time of 40 min) Fenton treatment removed about 46% of chemical oxygen demand (COD) and increased the five-day biochemical oxygen demand (BOD₅) to COD ratio (BOD₅/COD) from 0.01 to 0.15. The highest removal efficiency and biodegradability was achieved by ozone at higher pH values, solely or combined with H₂O₂. These results confirm the enhanced production of hydroxyl radical under such conditions. After the application for 60 min of ozone at 5.6 g O₃ h⁻¹, initial pH 7, and 400 mg L⁻¹ of hydrogen peroxide, COD removal efficiency was 72% and BOD₅/COD increased from 0.01 to 0.24. An estimation of the operating costs of the AOPs processes investigated revealed that Fe²⁺/H₂O₂ was the most economical system (8.2 € m⁻³ g⁻¹ of COD removed) to treat the landfill leachate. This economic study, however, should be treated with caution since it does not consider the initial investment, prices at plant scale, maintenance and labour costs.