二级Fenton氧化高浓度有机硅废水研究

采用二级Fenton氧化技术对可生化性差的高浓度有机硅废水进行处理,考察了不同因素对COD去除率的影响,对比了一级氧化和二级氧化的效果。结果表明对于COD为9 600 mg/L的高浓度有机硅废水,pH为3,[H2O2]/[Fe2+]=2∶1为最佳的反应条件,COD去除率随着H2O2的投加量的增大先增大而后减小,每200 mL水样中先投加20%的硫酸亚铁12 mL,然后分2次投加30%的H2O2各4 mL,氧化完成后调整pH值为7~8静止沉淀,COD去除率达89.2%。对于某绝缘电器厂的生产废水经二级Fenton氧化处理后,出水有机物浓度显著降低,可生化性提高,Fenton二级氧化可以作为高浓度有机硅废水的预处理工艺。     

Fe2+/H2O2法处理草浆纸厂废水的影响因素研究

Fenton试剂作为一种具有强氧化性的试剂,广泛地应用于废水处理的研究中.通过正交实验对Fenton试剂处理废水的几种影响因素进行了讨论,得出了影响因素的次序:Fe2 的投加量＞H2O2的投加量＞pH值＞反应时间.同时得到Fenton试剂处理造纸废水的最佳工艺条件:pH=5.0,FeSO4·7H2O的投加量为5.93g/L,H2O2的投加量为8.8‰(体积百分比),搅拌时间0.5 h,COD值由原来的2167 mg/L降至187 mg/L,COD去除率达到91.37%.     

Fenton氧化/混凝沉淀协同处理腈纶聚合废水

采用Fenton法处理湿法腈纶聚合废水,考察了H2O2投加量、Fe2+投加量、p H和反应时间等因素对氧化和混凝作用去除废水污染物的影响,并分析了废水可生化性和特征污染物的变化。结果表明,Fenton法可以有效去除废水中有机污染物,在初始p H为3.0,Fe2+投加量为15.0 mmol/L,H2O2投加量为90.0 mmol/L的条件下,反应120 min后废水COD去除率可以达到56.8%,其中氧化和混凝作用对应的去除率分别为43.3%和13.5%;处理后废水的BOD5/COD由0.24升高至0.43;处理后废水中丙烯腈以及其他多数有机污染物能被有效去除。     

Fenton试剂氧化预处理橡胶促进剂NS生产废水的研究

采用Fenton试剂氧化处理橡胶促进剂NS生产废水,研究H2O2、Fe2＋投加量及pH值对COD去除率的影响。通过实验,确定了Fenton试剂处理该废水的最佳操作条件：pH值为3,Fe2＋加入量为0.3 g/L,而H2O2为15 mL/L。     

Fenton氧化与铁炭微电解组合预处理DMF废水

对COD表征模拟废水中DMF去除率的可行性进行了探讨。在此基础上,分别对铁炭微电解、Fenton氧化-铁炭微电解和铁炭微电解-Fenton氧化组合工艺对DMF废水的处理效果进行分析,结果表明,Fenton氧化-铁炭微电解工艺的处理效果较好。在pH=5,反应时间为1 h,FeSO4·7H2O投加量为1 000 mg/L、H2O2投加量为2.67 mL/L和不曝气的最佳反应条件下,Fenton氧化-铁炭微电解工艺对实际废水和废液中COD的去除率分别达到66.67%和72.22%,从而验证了该工艺处理DMF废水的可行性。此外,Fenton氧化处理DMF废水过程实际上是将酰胺基团和羰基的不饱和双键氧化分解的过程。     

异相Fenton试剂催化氧化-混凝沉淀深度处理焦化废水

针对焦化废水二级生化处理出水COD、色度和浊度无法达标的问题,实验研究了异相Fenton试剂催化氧化法和混凝沉淀法以及二者联合深度处理焦化废水的效果,分别探讨了H2O2、FeOOH投加量、初始pH,混凝剂投加量及种类对COD去除的影响,确定了最佳运行条件,采用GC-MS分析了联合工艺对废水中有机物的去除规律。异相Fenton试剂催化氧化静态实验研究表明,当H2O2(10%)投加量为2 mL/300 mL,FeOOH投加量为3 g/L,初始pH为4~6之间,处理效果最佳;混凝沉淀实验中最佳的混凝剂为聚丙烯酰胺阳离子,最佳投加量为8 mg/L。异相Fenton试剂催化氧化-混凝沉淀联合工艺深度处理焦化废水,出水COD基本在90 mg/L左右,浊度为0.8NTU左右,色度为40度以下,满足国家污水综合排放二级标准(GB8978-1996)。GC-MS分析显示,联合工艺能有效减少废水中有机物的种类和浓度,并将废水中长链大分子化合物和杂环化合物分解为短链的小分子化合物,构成联合工艺出水COD的主要是小分子有机物,尤其是卤代烷烃含量较高。     

絮凝-Fenton试剂氧化处理印染废水

采用Fenton试剂对某染袜厂2种印染废水(印染红和印染蓝)进行处理。考察了硫酸亚铁投加量、双氧水投加量、反应时间及pH值对印染废水的色度及COD去除率的影响,通过正交实验确定了Fenton试剂处理该废水的最佳操作条件为:反应时间30 min、双氧水(30%)投加量4 mL/L、硫酸亚铁投加量300 mg/L、pH值为4左右。在最佳条件下,印染蓝废水经氧化处理后COD去除率大于80%,色度去除率95%以上;印染红废水需经絮凝预处理后再用Fenton试剂氧化处理,其脱色率达到了99.6%,COD去除率为91.2%,出水COD浓度为96 mg/L,可达标排放。     

超声波协同Fenton氧化法去除造纸法再造烟叶废水COD

采用单独Fenton氧化法和联合超声波Fenton氧化法去除经过生化处理后的造纸法再造烟叶废水COD,通过研究反应时间、H2O2和Fe2+用量对COD去除率的影响,确定最佳实验条件。结果显示,Fenton法和联合超声波Fenton法对COD最大去除率分别为66.18%和76.99%;对比结果发现,超声波可以减少Fenton反应时间,降低COD去除率最大时的Fenton试剂用量,保证高COD去除率的同时扩宽Fenton试剂用量范围,超声波协同Fenton反应的作用显著。     

UV/Fenton法预处理橡胶促进剂生产废水

采用UV/Fenton法对橡胶促进剂废水进行预处理.当原水COD约为3000 mg/L时,COD去除率可达65%以上,并得到最佳操作条件为:H2O2投加量为8 mL/L,Fe2 投加量为0.8 g/L,反应时间为30 min,pH=5;同时得到Fenton试剂处理该废水的最佳条件为:H2O2投加量为10 mL/L,Fe2 投加量为0.966 g/L,反应时间为30 min,pH=5;单独UV作用的最佳工艺条件为:反应时间为20 min,pH=5;并就3种处理方法进行了比较,发现UV对Fenton试剂处理橡胶促进剂废水具有一定促进作用.反应前后的紫外光谱说明,经UV/Fenton或Fenton反应后原水中的苯胺、硝基苯等物质已得到了彻底的氧化分解.     

超声波/Fenton处理含酚废水的影响因素

实验研究主要影响因素对超声波/Fenton试剂处理苯酚废水效果的影响,确定工艺参数。以人工配制的模拟苯酚废水为实验水样,通过静态实验研究p H值、Fe SO4·7H2O投加量、H2O2投加量和超声时间对苯酚和COD去除率的影响。研究结果表明,对于苯酚浓度为200 mg/L,COD为476.6 mg/L苯酚废水,在实验用水量为1 000 m L,p H值为6,Fe SO4·7H2O投加量为800 mg/L,H2O2投加量为Qth,超声时间为30 min的条件下,苯酚去除率可达到92.27%,COD去除率可达到82.48%,处理后苯酚浓度为14.80 mg/L,COD为83.50 mg/L。p H值、Fe SO4·7H2O投加量、H2O2投加量和超声时间对超声/Fenton工艺处理苯酚废水均有较显著地影响,工程应用时应给予足够的重视。     

Treatment of coking wastewater by an advanced Fenton oxidation process using iron powder and hydrogen peroxide

In this study the treatment of coking wastewater was investigated by an advanced Fenton oxidation process using iron powder and hydrogen peroxide. Particular attention was paid to the effect of initial pH, dosage of H₂O₂ and to improvement in biodegradation. The results showed that higher COD and total phenol removal rates were achieved with a decrease in initial pH and an increase in H₂O₂ dosage. At an initial pH of less than 6.5 and H₂O₂ concentration of 0.3 M, COD removal reached 44-50% and approximately 95% of total phenol removal was achieved at a reaction time of 1 h. The oxygen uptake rate of the effluent measured at a reaction time of 1 h increased by approximately 65% compared to that of the raw coking wastewater. This indicated that biodegradation of the coking wastewater was significantly improved. Several organic compounds, including bifuran, quinoline, resorcinol and benzofuranol were removed completely as determined by GC-MS analysis. The advanced Fenton oxidation process is an effective pretreatment method for the removal of organic pollutants from coking wastewater. This process increases biodegradation, and may be combined with a classical biological process to achieve effluent of high quality.     

Fenton-混凝法处理苯胺废水

农药生产过程中产生的苯胺废水,COD浓度高、生物毒性强、可生化性差,一般生化方法很难处理。研究了Fenton与PAC联用处理苯胺废水。结果表明,Fenton氧化处理苯胺废水在最佳条件为pH=6、m（H2O2）/m（COD）=1.8、n（H2O2）/n（Fe2＋）=8时,COD和色度去除率分别为78.4%和92.3%。Fenton氧化后废水B/C值由0.037提高到0.324。最佳条件下联用PAC,在投加量为320 mg/L时COD与色度去除率分别为83.6%和94.8%,并且处理时间显著缩短,实际应用中可减少水力停留时间和构筑物体积。     

铁炭微电解/Fenton试剂预处理土霉素废水的研究

研究了铁炭微电解/Fenton试剂法工艺对高浓度难生化处理的土霉素废水预处理效果.结果表明,当原水COD在6 000 mg/L、pH值为2.2时,铁炭微电解反应时间为80 min,铁炭微电解对原水COD的去除率>40%;铁炭微电解出水再投加220 mg/L的H2O2(30%)进行Fenton试剂法处理,常温下反应50 min对原水COD的去除率可提高到75%以上.铁炭微电解 Fenton试剂联合工艺的处理效果好、运行稳定、成本低廉,适宜对难降解的土霉素废水的预处理.     

Kinetic degradation of the pollutant guaiacol by dark Fenton and solar photo-Fenton processes

This work is first intended to optimize the experimental conditions for the maximum degradation of guaiacol (2-methoxyphenol) by Fenton’s reagent, and second, to improve the process efficiency through the use of solar radiation. Guaiacol is considered as a model compound of pulp and paper mill effluent. The experiments were carried out in a laboratory-scale reactor subjected or not to solar radiation. Hydrogen peroxide solution was continuously introduced into the reactor at a constant flow rate. The kinetics of organic matter decay was evaluated by means of the chemical oxygen demand (COD) and the absorbance measurements. The experimental results showed that the Fenton and solar photo-Fenton systems lead successfully to 90% elimination of COD and absorbance at 604 nm from a guaiacol solution under particular experimental conditions. The COD removal always obeyed a pseudo-first-order kinetics. The effect of pH, temperature, H₂O₂ dosing rate, initial concentration of Fe²⁺, and initial COD was investigated using the Fenton process. The solar photo-Fenton system needed less time and consequently less quantity of H₂O₂. Under the optimum experimental conditions, the solar photo-Fenton process needs a dose of H₂O₂ 40% lower than that used in the Fenton process to remove 90% of COD.     

Fenton氧化法深度处理甲醛废水

采用Fenton氧化法深度处理经生化降解后的甲醛废水,结果表明,Fenton氧化法深度处理甲醛废水是可行的,在合适的反应条件下,降解初始COD为150 mg/L左右的甲醛废水,COD去除率达30%以上;Fe2+与H2O2的投加比例、投加量及投加方式、反应温度、pH、反应时间对处理效果都有不同程度的影响。     

Heterocatalytic Fenton oxidation process for the treatment of tannery effluent: kinetic and thermodynamic studies

Background, aim, scope

Treatment of wastewater has become significant with the declining water resources. The presence of recalcitrant organics is the major issue in meeting the pollution control board norms in India. The theme of the present investigation was on partial or complete removal of pollutants or their transformation into less toxic and more biodegradable products by heterogeneous Fenton oxidation process using mesoporous activated carbon (MAC) as the catalyst.

Materials and methods

Ferrous sulfate (FeSO₄·7H₂O), sulfuric acid (36?N, specific gravity 1.81, 98% purity), hydrogen peroxide (50% v/v) and all other chemicals used in this study were of analytical grade (Merck). Two reactors, each of height 50?cm and diameter 6?cm, were fabricated with PVC while one reactor was packed with MAC of mass 150?g and other without MAC served as control.

Results and discussion

The oxidation process was presented with kinetic and thermodynamic constants for the removal of COD, BOD, and TOC from the wastewater. The activation energy (Ea) for homogeneous and heterogeneous Fenton oxidation processes were 44.79 and 25.89?kJ/mol, respectively. The thermodynamic parameters ??G, ??H, and ??S were calculated for the oxidation processes using Van??t Hoff equation. Furthermore, the degradation of organics was confirmed through FTIR and UV?Cvisible spectroscopy, and cyclic voltammetry.

Conclusions

The heterocatalytic Fenton oxidation process efficiently increased the biodegradability index (BOD/COD) of the tannery effluent. The optimized conditions for the heterocatalytic Fenton oxidation of organics in tannery effluent were pH 3.5, reaction time?C4?h, and H₂O₂/FeSO₄·7H₂O in the molar ratio of 2:1.     

微电解-Fenton深度处理制药废水影响因素与参数控制

采用铁炭微电解-Fenton联合工艺深度处理制药废水生化出水,探讨了初始pH、曝气量、反应时间等因素对微电解出水Fe2+和Fe3+变化规律、COD降解速率以及后续Fenton氧化效果的影响,为优化微电解-Fenton氧化联合工艺提出了微电解间歇加酸的理论。间歇加酸可提高微电解系统中COD降解速率和Fe2+含量,使后续Fenton氧化无需投加FeSO4·7H2O即可达到较好的COD去除效果。结果表明,当初始pH=2.5,曝气量为0.6 m3/h,间歇加酸30 min/次,微电解反应2 h,出水投加1 mL/L的H2O2进行Fenton氧化2 h,COD总去除率可达81.33%;间歇加酸30 min/次可将微电解反应2 h出水Fe2+浓度从50 mg/L提高至151 mg/L,COD降解速率从10.6 mg COD/(L·h)提高至22.2 mg COD/(L·h)。     

焦化废水泡沫分离液的Fenton催化氧化预处理

以焦化废水处理过程产生的泡沫分离液为研究对象,对其进行Fenton催化氧化处理实验,考察H₂O₂用量、Fe²⁺浓度、pH和反应时间4个因素对处理效果的影响,并结合GC/MS方法比较处理前后泡沫分离液中有机物的种类及其生物降解性的变化。结果表明,采用［H₂O₂］=100 mmol/L、［Fe²⁺］=100 mg/L、pH=3、反应时间为30 min的Fenton催化氧化反应条件,可以使分离液的COD去除率达到68%以上;经Fenton处理后,分离液的B/C值由0.12提高至0.38,生物降解性明显改善;通过GC/MS的分析,基本明确分离液中含有的有机物主要为酚、胺、腈、酯类有机物及喹啉、吡啶等杂环化合物,大多数属于难降解且生物毒性较强的有机物。针对这些复杂组分共存的泡沫分离液,利用Fenton试剂较强的氧化能力能够将其含有的有毒/难降解有机物转化为低毒或无毒的小分子有机物,为其后续的生物处理创造良好的条件。     

电-Fenton法预处理干法腈纶生产废水

以Ti金属网为阴极,Ti基RuO2涂层形稳电极为阳极,采用外加H2O2和Fe2+的方式,研究了电-Fenton氧化预处理干法腈纶生产废水的工艺,考察了H2O2投加量、Fe2+投加量、pH值和电流强度等因素对污染物降解过程的影响,分析了废水可生化性和污染物变化规律。结果表明,电-Fenton法可以有效降解废水中有机污染物,使废水COD迅速降低,在初始pH值为3.0,Fe2+投加量为5.0 mmol/L,H2O2投加量为60.0 mmol/L,电流强度0.2 A的条件下,反应120 min后COD去除率可以达到44.0%以上;反应过程中H2O2的投加方式对电-Fenton法的处理效果具有明显影响,H2O2分6次投加可以使COD去除率由一次性投加时的44.8%提高至54.1%;处理后废水的BOD5/COD由0.29升高至0.68;GC-MS结果表明,经电-Fenton法预处理后,废水中多数芳香族化合物和特征污染物能被有效降解。