Fenton试剂氧化法对染料中间体废水的深度处理

以实际染料中间体废水经铁催化内电解、水解酸化、好氧生化组合工艺处理后的出水为研究对象,考察了Fenton试剂氧化法深度处理染料中间体废水的效果和影响因素。当进水CODcr为187．5mg／L、色度为1085倍时,出水CODcr下降到59．2mg／L,去除率为68．4％;色度下降到129倍,去除率为88．1％。     

Fenton氧化深度处理焦化废水的研究

采用Fenton氧化对焦化废水进行了深度处理。结果表明：Fenton氧化反应迅速,可迅速降低焦化废水生化出水的COD;H2O2和Fe2＋的投加量对Fenton氧化具有明显的影响;pH=3时反应体系具有最佳的COD去除效果。在H2O2投加量为1.994 mL/L,FeSO4.7H2O投加量为0.543 g/L,pH=3,温度为35℃的条件下,反应出水COD低于100 mg/L,去除率可达72.7%;Fenton氧化可有效去除生化出水中的难降解有机物。实验结果表明Fenton氧化是深度处理焦化废水的有效工艺。     

Fenton氧化法处理填埋渗滤液

Central composite design (CCD), the most popular design of response surface methodology (RSM), was employed to investigate the effect of total organic carbon (TOC) ratio of high molecular weight organic matter (HMW) to low molecular weight organic matter (LMW), the LMW strength and molar ratio of hydrogen peroxide to ferrous ion on landfill leachate treatment by Fention process. Based on the experimental data, a response surface quadratic model in terms of actual factors was obtained through analysis of variance (ANOVA). The model showed that TOC removal increased with the increase of HMW to LMW ratio and the decrease of LMW strength. There existed an optimal hydrogen peroxide to ferrous ion molar ratio for TOC removal.     

Fenton氧化法在废水处理中的研究进展

阐述了Fenton试剂的氧化机理,在此基础上重点介绍了光Fenton技术、电Fenton技术、超声波Fenton技术在废水处理中的机理与研究现状,展望了未来Fenton氧化技术的发展方向.     

Fenton试剂氧化处理印染废水的实验研究

对Fenlon试剂氧化处理印染废水进行了研究。考察了反应时间、双氧水投加量、硫酸亚铁投加量及PH值对印染废水的色度及COD去除率的影响。通过对印染废水进行正交实验及单因素分析实验。确定了Fenton试剂处理此印染废水的最佳实验条件。     

Optimization of High-Strength Semiconductor Wastewater by Sequential Fenton Oxidation and Gas-Induced Ozonation

Treatment of organic-containing wastewater from a semiconductor plant treated by chemical oxidation was experimentally investigated. The wastewater was characterized by strong color, high chemical oxygen demand (COD) and low biodegradability. Treatment of this wastewater by traditional activated sludge method was essentially impossible. In the present work, advanced chemical oxidations by Fenton’s reagent and ozonation were utilized to tackle the problems of wastewater color and low biodegradability. To facilitate the particulate removal after Fenton oxidation, chemical coagulation using polyaluminum chloride and polymer was adopted as an integral part of the Fenton process. Experimental tests were conducted to determine the effectiveness and the optimum operating conditions of the chemical oxidation methods. Test results demonstrate that the two advanced oxidations were able to lower the wastewater COD concentration from as high as 15,000 mg/L to below 150 mg/L and completely eliminating the wastewater color, resulting in very good quality of the treated wastewater. A generalized kinetic model was employed to describe and elucidate the oxidation mechanisms of oxidation processes and the kinetic parameters of the models were appropriately identified using the test data.     

Combination of Chemical Coagulation and Photo-Fenton Oxidation Process for the Treatment of Beet Sugar Industry Wastewater: Optimization of Process Conditions by Response Surface Methodology

The beet sugar industry generates large volumes of wastewater with high levels of chemical oxygen demand (COD) and color content, which are discharged into the nearby environment without adequate treatment. The aim of this study was to investigate the treatment possibility of this wastewater by using the photo-Fenton oxidation combined with a coagulation process. Central composite design and response surface methodology were used to evaluate the relationships between color and COD reduction and the photo-Fenton oxidation parameters (i.e. Fenton’s reagent dosage, pH, and reaction time).

The combined treatment results showed 59% of COD and 83.9% of color removal were obtained at optimum conditions (pH: 6.2; Fe²⁺ dosage: 20 ppm; H₂O₂ dosage: 1500 ppm; and reaction time of 15 min). Finally, the results of gel permeation chromatography showed that low molecular weight fraction of the wastewater impurities is more degraded than high molecular weight fraction during oxidation/coagulation process. Therefore, the results obtained from this study showed that an appropriate combined method for the treatment of beet sugar industry wastewater can be designed and implemented.     

Fenton-生物接触氧化处理综合电镀废水

电镀综合废水由于水量大、水质复杂导致处理难度大、处理成本高的困难。在分析废水水质特点和传统处理工艺的基础上,采用Fenton-生物接触氧化工艺对电镀综合废水进行处理,运行结果表明,该联合工艺对污染物具有显著和高效的去除效果,出水COD≤80mg／L,Cu^2＋≤0．5mgL,Ni^2＋≤0．5mg／L,Cr^6＋≤0．4,氰化物≤0．4mg／L,各项水质指标均优于《广东省水污染物排放限制》（DB44,26—2001）第二时段的一级标准。     

Investigation of Performance Improvement of the Evaporation Process in Raw Sugar Manufacturing by Increasing Heat Transfer Surfaces

A multiple-effect evaporator is used to evaporate water from sugar juice in a series of pressure vessels. Steam is used for evaporation in the first vessel, and vapor from all vessels, except the last one is used for evaporation in subsequent vessels. In order for evaporator surfaces to be used efficiently, juice entering the evaporator should be at the saturation temperature. Therefore, incoming juice with a low temperature must be heated in a juice heater. The heating medium in the juice heater is vapor bled from the evaporator. It is apparent that the multiple-effect evaporator and the juice heater interact through mass and energy balances. Previous investigations have focused on only the multiple-effect evaporator, and paid little attention to the juice heater. This paper presents the model of the interaction between the multiple-effect evaporator and the juice heater. The model is used to investigate how variations of surfaces in the evaporator and the juice heater affect the two performance parameters of the system, which are the amount of sugar juice processed by the system and the ratio of the amount of water evaporated from sugar juice in the evaporator to the amount of high-pressure steam required by the evaporator.     

Degradation of Recalcitrant Surfactants in Wastewater by Ozonation and Advanced Oxidation Processes: A Review

Surfactants are used in varieties of industrial cleansing processes as well as in consumer products. Spent surfactants normally enter domestic or industrial wastewater and are treated biologically. However, some of them are resistant to biodegradation and are released into the environment. Thus, the toxicity and environmental persistence of these surfactants are emerging concerns. Based on extensive review of the literature, ozonation and advanced oxidation using various combinations of ozone, hydrogen peroxide, ultraviolet light irradiation, and iron salts were found effective in degrading recalcitrant surfactants, including linear alkylbenzene sulfonates, alkylphenol ethoxylates, and quaternary ammonium surfactants. Biodegradability of these surfactants was improved after the treatment to some extent in the aqueous solution as well as in real wastewaters.     

乙炔气体湿法净化及改造

针对50万米~3/年乙炔站清净工序的生产性质及要求,采用了以次氯酸钠液湿法净化乙炔气的方法,并阐述了清净工序的改造设计。净化后的乙炔气中硫化氢、磷化氢含量总和小于10ppm,净化效果好,安全可靠,成本低,效益好,值得乙炔站推广。     

Purification of Wet‐Process Phosphoric Acid by Hydrogen Peroxide Oxidation,Activated Carbon Adsorption and Electrooxidation

In this work, three technologies are studied for the purification of phosphoric acid produced by the wet process: chemical oxidation with hydrogen peroxide, adsorption onto activated carbon, and electrochemical oxidation by boron‐doped diamond anodes. The treatment of wet‐process phosphoric acid by chemical oxidation with H₂O₂ as oxidizing agent can remove 75 % of the initial TOC as maximum, indicating that this wet‐process phosphoric acid contains an important amount of organics that cannot be oxidized by hydrogen peroxide under the operation conditions used. High temperatures and hydrogen peroxide/TOC ratios close to 150 g H₂O₂/g TOC allow obtaining the best chemical oxidation results. The adsorption onto activated carbon can remove between 40 and 60 % of the initial TOC as maximum. Adsorption times of 2 hours and activated carbon/WPA ratios close to 12 g AC/Kg WTP assure both steady state and maximum adsorption of organics. The electrochemical process is the only technique by which complete mineralization of WPA organics can be achieved. Operating at 60 mA cm^–2 and at room temperature, high current efficiencies are achieved which only seem to decrease by mass transport limitations.     

Removal of Adsorbable Organic Halides from Water Containing Bromide Ions by Conventional and Advanced Oxidation

The article focuses on an assessment of adsorbable organic halides degradation during the process of conventional ozonation and advanced oxidation as far as the water containing bromides is concerned. The amount of AOX in the water examined varied from 59 to 105 μg Cl^?/L, and the bromides concentration exceeded 200 μg Br^?/L. The effects obtained by O₃ and O₃/UV methods were compared with the results achieved for the water which underwent only UV irradiation. The analysis of presented research results shows that out of the examined oxidation methods, in water of pH 6.8–9.5 and temperature of approximately 287 K, the highest degree of AOX decomposition, was achieved by UV irradiation of water, which was previously subjected to ozonation. However, when the ozone dose reached ≥ 0.3 mg O₃/mg C in an alkaline environment, bromates were formed in amounts exceeding the maximum contaminant level in both processes.     

Oxidation by UV and Ozone of Organic Contaminants Dissolved in Deionized and Raw Mains Water

Organic contaminants dissolved in deionized pretreated and raw mains water were reacted with ultraviolet light and ozone. Ozone first was used for partial oxidation followed by ozone combined with ultraviolet radiation to produce total oxidation. The reduction of TOC level and direct oxidation of halogenated compounds were measured throughout the treatment process. The rate of TOC reduction was compared for ozone injected upstream and inside the reactor.     

The Advanced Oxidation Process of Phenol Solution by O3/H2O2 in a Rotating Packed Bed

This article presents experimental investigation on the oxidative treatment of phenol in water by O₃/H₂O₂ in a rotating packed bed (RPB). It was found that the phenol degradation ratio increased with increasing rotation speed, initial pH value of phenol solution, and temperature. The degradation ratio of phenol had a peak value with increasing H₂O₂ concentration. The optimum operating conditions in this study were determined as an H₂O₂ concentration of 6.5 mM and a rotation speed of 1200 rpm. Phenol degradation ratio reached 100% at an initial phenol concentration of 40 mg/L in the O₃/H₂O₂ process.     

Oxidation of Acid Red-151 Aqueous Solutions by the Peroxone Process and its Kinetic Evaluation

Oxidation of an azo dye solution, namely, Acid Red 151 by the peroxone process was investigated experimentally at different pH values, initial dye and ozone concentrations, and the initial molar ratios (r) of hydrogen peroxide to ozone. At pH 2.5 in this process, the obtained color and chemical oxygen demand (COD) removals were higher than those at pH of 7 and 10. The best value of r yielding the highest treatment efficiency at each pH was determined as 0.5. The application of the “initial rates method” to the kinetic data for peroxone oxidation of aqueous Acid Red 151 solutions showed that the individual orders with respect to O₃ and dye were one, the total order of the reaction being two. The rate constants based on the initial rates of dye degradation were determined as 98.9, 77.3 and 65.7 mM^?1min^?1 at the pH values of 2.5, 7 and 10, respectively.