Fenton试剂液相氧化法净化含H_2S的气体

利用Fenton试剂液相氧化法净化含H2S的气体,研究了初始pH值、温度、H2S浓度、H2O2浓度、气体流量、[H2O2]/[Fe2+]比值、金属离子等因素对H2S去除率的影响.结果表明,当pH<2.52时,pH值升高,去除率逐渐提高;当pH>2.52时,去除率下降;pH=2.52时,去除效率最高.去除率随H2O2浓度增加而提高;H2O2浓度一定时,去除率随[H2O2]/[Fe2+]比值的增加而升高;[H2O2]/[Fe2+]接近于1时达到最大.温度提高,去除率提高.实验条件下,去除率随气体流量的增加而下降.入口H2S浓度越低去除率越高.Fe3+对Fenton反应有促进作用,添加金属离子的Fenton试剂氧化H2S能力顺序为Fe2++Fe3+>Fe2+>Fe3+.

Fenton试剂对水体中多环芳烃(PAHs)污染物的去除效果研究

多环芳烃是一类具有致癌特性且采用常规处理工艺难以有效去除的有机污染物,本论文研究了Fenton试剂对水体中多环芳烃污染物芴、菲、蒽的去除效果,对影响多环芳烃去除率的几种因素包括反应时间、FeSO4浓度、H2O2浓度及pH值进行了探讨。结论表明当反应时间为60min,FeSO4和H2O2浓度分别为3.0和20mmol.L-1,pH值为4.0时,3种多环芳烃的去除效果最佳,去除率分别达到78.3%、82.5%和99.0%。比较了Fenton试剂法、UV/Fenton法和UV/草酸铁/H2O2法对多环芳烃的去除,结论表明这3种芬顿系统对多环芳烃的去除率相差不大,且均能获得较满意的去除效果。

纳米CuFe_2O_4/K_2S_2O_8非均相类Fenton体系对橙黄Ⅱ降解性能的研究

采用柠檬酸辅助溶胶-凝胶法制备了纳米CuFe_2O_4,以其为非均相催化剂,开展了纳米CuFe_2O_4/K_2S_2O_8非均相类Fenton体系对橙黄Ⅱ降解性能的研究,考察了纳米CuFe_2O_4焙烧温度对其结构及催化性能的影响,探讨了初始pH、K_2S_2O_8投加量和橙黄Ⅱ初始浓度对该体系降解性能的影响,评价了纳米CuFe_2O_4的稳定性,并在此基础上,探究了纳米CuFe_2O_4/K_2S_2O_8非均相类Fenton体系对橙黄Ⅱ的降解机制。结果表明:(1)纳米CuFe_2O_4最佳焙烧温度为400℃,此焙烧温度下制备的纳米CuFe_2O_4晶型较好、比表面积较大、催化活性和稳定性较高;(2)在纳米CuFe_2O_4/K_2S_2O_8非均相类Fenton体系中,橙黄Ⅱ快速降解最适宜的反应条件为初始pH 5.3、K_2S_2O_8投加量0.5g/L、橙黄Ⅱ初始质量浓度20mg/L、纳米CuFe_2O_4投加量1g/L;(3)纳米CuFe_2O_4在反应中的稳定性较好,金属溶出量较低,可通过有效催化K_2S_2O_8分解为SO_4^-·和HO·,实现橙黄Ⅱ的开环降解。

Treatment of Enzymolysis Wastewater by Centrifugation- Coagulation- Fenton Reagent Oxidation- Adsorption Process

[ Objective ] The study aimed to discuss the optimal conditions for the treatment of enzymolysis wastewater by centrifugation - coagu- lation - Fenton reagent oxidation - adsorption process. [ Metbod] According to the water-quality characteristics of wastewater from a heparin so- dium production factory of Jiangsu Province, enzymolysis wastewater was segregated from intestinal lavage wastewater and treated through cen- trifugation- coagulation- Fenton reagent oxidation-adsorption process, and the optimal technical parameters were determined. E Resultl After enzymolysis wastewater was centrifuged at a speed of 4 000 rpm, 0.6 g/L CTS as the coagulant was added to the supematant. Hereafter, pH of the coagulated effluent was adjusted to 3, and then 1.5% （V/V） H2O2 was added to the coagulated effluent; a certain amount of ferrous sul- fate （n H2O2-.n FeSO4 . 7H2O =8：1 ） was added to the mixture; the reaction conducted for 30 min, and then solution pH was adjusted to about 9. Finally, the oxidized effluent flowed through a resin red until the adsorptive capacity reached 240 BV, and COD of the effluent water was lower than 100 mg/L, meeting the Grade-I standard of Comprehensive Discharge Standard of Sewage （GB8978-1996）. [Condusio] The research could provide a new process for the treatment of enzymolysis wastewater.

Synthesis of Ag/AgCl/Fe-S plasmonic catalyst for bisphenol A degradation in heterogeneous photo-Fenton system under visible light irradiation

A novel plasmonic photo‐Fenton catalyst of Ag/AgCl/Fe‐S was synthesized by ion exchange and photoreduction methods.The obtained catalyst was characterized by X‐ray diffraction,X‐ray photoelectron spectroscopy,scanning electron microscope imaging,and Brunauer‐Emmett‐Teller measurements.Moreover,the photocatalytic activity of Ag/AgCl/Fe‐S was investigated for its degradation activity towards bisphenol A(BPA)as target pollutant under visible light irradiation.The effects of H2O2concentration,pH value,illumination intensity,and catalyst dosage on BPA degradation were examined.Our results indicated that the Ag/AgCl material was successfully loaded onto Fe‐sepiolite and showed a high photocatalytic activity under illumination by visible light.Furthermore,active species capture experiments were performed to explore the photocatalytic mechanism of the Ag/AgCl/Fe‐S in this heterogeneous photo‐Fenton process,where the major active species included hydroxyl radicals(?OH)and holes(h+).

Degradation of polyvinyl-alcohol wastewater by Fenton’s reagent: Condition optimization and enhanced biodegradability

The pretreatment of refractory polyvinyl-alcohol （PVA） wastewater with low value of CODcr by Fenton＇s reagent was investigated to enhance the biodegradabilily. The effects of operating conditions such as pH of the solution, Fe2＋ dosage, H2O2 dosage, reaction time and initial PVA concentration on the removal efficiency of CODCr were discussed. It is demonstrated that the optimum value of pH for removal of CODcr is 5 and the most suitable dosages of H2O2 （2%） and FeSO4 （10 mg/L） are 5% and 8.0%, respectively. When the initial CODcr value of the PVA water is 760 mg/L, the favorable reaction time is 110 min. Under these optimum conditions, the removal ratio of CODcr is 58.6% 61.4%, and the value of biodegradability （CODB/CODcr） increases markedly from 8.9% 9.7% to 62.6% 68.3%.

Treatment of pharmaceutical wastewater containing recalcitrant compounds in a Fenton-coagulation process

The advanced treatment using integrated Fenton＇s reaction and coagulation process was investigated in this study. Before the advancement, the pharmaceutical wastewater containing lincomycin hydrochloride was pretreated by UASB （upflow anaerobic sludge bed） and a SBR （sequencing batch reactor） process. The residual recalcitrant compounds, measured by gas chromatographymass spectrometry （GC-MS）, mainly consisted of alcohols, phenols, and nitrogenous and sulfur compounds. The experimental results indicated that when the Fenton＇s reaction was conducted at pH=3.0, H2O2CODOcr=0.27, H2O2/Fe^2＋=3：1 and 30 min of reaction time, and the coagulation process operated at a sulfate aluminum concentration of 800 mg/L and pH value of 5.0, the color and COD in the wastewater decreased by 94% and 73%, respectively; with a finale COD concentration of 267 mg/L and color level of 40 units, meeting the secondary standard of GB8978-1996 for industrial wastewater.

Treatment of 2-phenylamino-3-methyl-6-di-n-butylaminofluoran production effluent by combination of biological treatments and Fenton's oxidation

High strength refractory organic stream is produced during the production of 2-phenylamino-3-methyl-6-di-n-butylaminofluoran （One Dye Black 2, abbr. ODB 2）, a novel heat-sensitive material with a promising market. In this study, a combination of acidificationprecipitation, primary biological treatment, Fenton＇s oxidation and another biological treatment was successfully used for the removal of COD from 18000-25000 mg/L to below 200 mg/L from the ODB 2 production wastewater in a pilot experiment. A COD removal of 70%-80% was achieved by acidification-precipitation under a pH of 2.5-3.0. The first step biodegradafion permitted an average COD removal of 70% under an hydraulic residence time （HRT） of 30 h. By batch tests, the optimum conditions of Fenton＇s oxidation were acquired as： Fe^2＋ dose 6.0 mmol/L; H2O2 dose 3000 mg/L; and reaction time 6 h. The second step biological treatment could ensure an effluent COD below 200 mg/L under an HRT of 10 h following the Fenton＇s treatment.

Treatment of Wastewater Containing RDX by Fenton's Reagent

Fenton's reagent was employed to treat the wastewater containing RDX.The effects of FeSO4 concentration,H2O2 concentration,pH value,reaction time,temperature and initial COD of wastewater on residual COD of wastewater were investigated.The results show that the optimum FeSO4 concentration and pH are 700 mg/L and 2.5,respectively,and the residual COD of wastewater decreases with the rise in H2O2 concentration,but increases with the rise in temperature.After Fenton's reagent treatment,the initial COD of less than 874 mg/L wastewater can meet effluent standard.Under conditions of 100 mg/L H2O2,437 mg/L initial COD and 15 ℃ temperature,the lowest residual COD is obtained at 83.80 mg/L in 5 min.

Investigations on the Degradation of Triazine Herbicides in Water by Photo-Fenton Process

In this work, the degradation of 2-chloro-4,6-diamino-1,3,5-triazine in aqueous solutions by photo-Fenton process has been investigated. The preliminary results have shown that the degradation of 2-chloro-4,6-diamino-1,3,5-triazine by photo-Fenton process is more rapid and more effective than Fenton and UV/H2O2 processes. The effects of certain experimental parameters on kinetics and efficiency of the degradation of 2-chloro-4,6,-diamino-1,3,5-triazine by photo-Fenton process, have been evaluated. Under optimal conditions, photo-Fenton process achieved more than 90% of chloride release and about 30% of nitrate formation. The results of total organic carbon (TOC) and total Kjeldahl nitrogen (TKN) analyses have shown that no carbon dioxide and ammonia are formed during photo-Fenton treatment of aqueous solutions containing 40 mg/L triazine. These results indicate that only substituent groups of triazine ring are released;however, nitrogen atoms of triazine ring remain unaffected. A simple mechanism of degradation of 2-chloro-4,6-diamino-1,3,5-triazine has been proposed. The degradation starts by a rapid release of chlorine atoms as chloride ions to form 2-hydroxy-4,6-diamino-1,3,5-triazine. The amino groups of 2-hydroxy-4,6-diamino-1,3,5-triazine undergo are oxidized into nitro groups by hydroxyl radicals to form 2-hydroxy-4,6-dinitro-1,3,5-triazine which undergoes a slow release of nitro groups and their substitution with hydroxyl groups to form cyanuric acid and nitrate ions. The degradation of cyanuric acid by photo-Fenton process has also been investigated. The results of TOC and TKN analyzes show that no carbon dioxide is formed during the treatment.

Degradation of Silicone Rubbers in Fenton's Reagents

Gaskets are applied in PEMFCs（proton exchange membrane fuel cells） to keep reactant gases and liquid within their respective regions, which are of great significance for the both sealing and electrochemical performance of fuel cells during the long-term operation. In this study, the degradation of silicone rubbers, often selected as seals in PEMFCs, in Fenton＇s reagents with different H_2O_2 concentrations was investigated. The changes in chemical properties, mechanical behavior and surface morphology of the samples were studied before and after exposure to the test environment over time. It is found that increasing H_2O_2 concentration will degrade the rubbers more severely. The experimental results elucidate the degradation mechanism of silicone rubbers in Fenton＇s reagents and the influence of H_2O_2 in the degradation process.

强化硫化黑染色废水中S^(2-)去除的电絮凝体系

为提高硫化黑染色废水中S^(2-)去除效率,以镁、铁作为交替阳极,选择交流电源构建电絮凝-芬顿耦合体系。采用响应曲面法(RSM)对体系参数如施加电压、电解时间、初始pH值、H_(2)O_(2)用量进行优化设计与验证,探究其对S^(2-)去除、色度、化学需氧量(COD)的影响。结果表明:H_(2)O_(2)添加量对废水COD去除率和S^(2-)去除率有一定影响,S^(2-)浓度受多因素的复合效果影响较明显。在施加电压27V、电解时间40min、初始pH值为5.9、H_(2)O_(2)为0.4mL,S^(2-)去除率最高,达到79.41%,此时COD去除率为48.08%,色度30倍。

Sono-Photo Fenton Treatment of Liquid Waste Containing Ethylenediaminetetraacetic Acid (EDTA)

Ethylenediaminetetraacetic acid (EDTA) is a chelating agent that has been used for decontamination purposes in nuclear industry. The presence of EDTA in decontamination wastes can cause complexation of the cations resulting into interferences in their removal by various treatment processes such as chemical precipitation, ion exchange etc. Further, it might also impart elevated leachability of cationic contaminants from the conditioned wastes immobilized in cement or other matrices and can negatively influence the quality of the final form of waste. In the present study, kinetics of degradation of EDTA (20,000 mg/l) by employing either Photo-Fenton process using UV (15 W λmax = 253.7 nm) or Sono-Fenton process using ultrasound at 130 KHz or simultaneous Sono-Photo Fenton process has been investigated. EDTA is effectively degraded by the synergistic effect of both Photo Fenton and Sono Fenton process. All the above mentioned processes were found to follow a first order kinetics reaction. From the observed pH changes during the oxidation processes, it can be concluded that there is a loss of chelating ability of EDTA. Formation of amides was con- firmed during the degradation processes.

Kinetics of Degradation of Eosin Y by One of the Advanced Oxidation Processes (AOPs)—Fenton’s Process

Kinetics of homogeneous degradation of Eosin Y (EY), also known as Acid red 87 (CI 45380), are studied, mostly using Fenton’s process, at 30℃ by monitoring its absorbance at 517 nm (λmax of EY). This process is one of the advanced oxidation processes (AOPs). Mixture of H2O2 and Fe(II) ion in acetate buffer medium (pH 2.74 - 4.56) generates hydroxyl free radicals (?OH) which attack the dye molecules, resulting in degradation of the dye molecules. Results show that the initial rate of EY degradation decreases with the increasing of solution pH because of removal of kinetically important Fe (iron) species through formation of ferric hydroxide. On the other hand, the rate increases with increasing the concentrations of H2O2, Fe(II) and EY at low solution pH. The initial rate increases with increasing of concentration of H2O2 and, subsequently remains unaffected with further increase of its concentration at a constant Fe(II) concentration because of the enhanced scavenging environment created by H2O2 at its higher concentration. The initial rate also increases with increasing of concentration of Fe(II) at a constant H2O2 concentration and remains unaffected with its further increase. EY concentration also enhances the initial rate at low pH. However, the initial rate is significantly enhanced by UV light. This is because of formation of additional hydroxyl radicals through excitation of the dye molecules by UV light. During the period of experiment, EY in aqueous solution alone hardly suffered any degradation. Degradation mechanism of EY by the Fenton and photo-Fenton’s processes is also discussed. Statistical analysis was used to validate the experimental results. Low values of the standard deviation for both the initial rate and % degradation indicated the consistency of the experimental data.

类Fenton法的Fe^0/Na2S2O8体系对甲基橙降解研究

本文基于Fe^0/Na2S2O8类Fenton体系,探索各因素(pH,PDS投加量,Fe投加量,反应温度及甲基橙浓度)对甲基橙(MO)的降解效果。实验结果表明:在pH=4,MO初始反应溶度为100 mg/L时,PDS投加量为0.912 mmol/L,Fe^0投加量为0.16 g/L时,体系反应150min后的降解率为81.9%,表观反应速率常数k为0.067 min-1。Fe^0活化过硫酸盐体系对MO溶液的降解符合一级反应动力学规律,动力学方程为:K=0.0894exp(-4838/RT)[Co]0.2004[PDS]0.0876[Fe^0]0.712,且反应条件对降解率影响顺序分别为PDS投加量<MO初始浓度<Fe^0投加量。

第十九讲“基于均匀设计的类Fenton's体系去除污染土壤中蒽和芘的研究”三种数据处理技术讨论

前几个月,李森、张杨给我送来《环境科学学报》2015年4月发表的题为'基于均匀设计的类Fenton’s体系去除污染土壤中蒽和芘的研究'文章,该文章作者为李森、张杨、罗勇、商照聪、徐静安。笔者作了认真阅读,全文有6.5个页面,内容充实。按照我的工作摘录,2013年8月21日开始多次讨论李森博士(海归)进上海化工研究院后的第一个立项——污染土壤中挥发性有机物脱除研究。2013年10月15日。

载铜地质聚合物微球的制备及其催化降解双酚S的性能

传统的芬顿反应因在废水处理过程中会产生大量富含金属污泥而应用受限。本研究采用悬浮固化法得到了一种低成本、易回收、绿色的多孔地质聚合物微球(GM),将其作为载体通过浸渍法制备了载铜地质聚合物微球(Cu-GM),作为类芬顿反应催化剂,催化H_(2)O_(2)降解水中的双酚S(BPS)。SEM、XRD、BET和XPS等一系列表征结果表明,Cu^(+/2+)被稳定固定在GM表面。进一步探究了Cu-GM用量、H_(2)O_(2)用量、BPS浓度和溶液初始p H对催化降解的影响。结果表明,在优化条件下,Cu-GM在480min内对BPS的去除率可达99.3%,催化降解过程符合一级反应动力学。通过自由基淬灭实验发现,在催化降解过程中·OH和^(1)O_(2)是主要活性物质。循环实验表明Cu-GM具有良好的重复利用性,在去除水中有机污染物方面有着极大的应用潜力。

电絮凝法和Fenton试剂法处理染料车间废水的性能

分别采用Fenton试剂氧化法和电絮凝法对染料生产车间废水进行预处理实验.采用铁阳极电絮凝,在最佳电流密度为12.5 mA/cm2时COD去除率为20.54%;以铝为阳极时在最佳电流密度为8.33 mA/cm2时COD去除率为37.57%.考察了采用Fenton试剂氧化法处理时不同实验因素对COD去除率的影响,确定了硫酸亚铁投加量600 mg/L,过氧化氢投加量6 mL/L,pH值2.21,反应时间为90 min的最佳操作条件,此时COD去除率为74.62%,处理药剂成本为39.1元/t COD.结果表明:电絮凝方法中采用铝为阳极时处理效果优于铁电极;与电絮凝法相比,Fenton试剂氧化法是一种高效低耗的预处理方法.

Fenton试剂的发展及在废水处理中的应用

Fenton在废水处理中具有独特的优势,是一种很有应用前景的废水处理技术。文章介绍了该技术的发展过程、主要类型,尤其介绍了和其它方法联合的优势,以及应用情况,并对各类型的优势、问题、发展趋势作出评述。

Fenton试剂对垃圾渗滤液中腐殖质的氧化/混凝作用

The experiments focused on the Fenton treatment of humic substances(HS) in concentrated landfill leachate rejected by reverse osmosis(RO).The changes in dissolved organic matter by oxidation/coagulation were assessed by using gross organic parameters such as chemical oxygen demand(COD),total organic carbon(TOC),UV254 and COD/TOC molar ratio during the treatment with Fenton reagent.The results demonstrated that the humic substances removal efficiency(from 11.9% to 89.5%) was higher than that of COD(from 9.6% to 75.2%) and there was a good correlation between humic substances degradation and COD removal.This study showed that the oxidation efficiency controlled the coagulation efficiency,so high oxidation efficiency may cause relatively low coagulation.The change of(COD/TOC)oxid indicated that the oxidation reaction was ultimate degradation under the condition of pH= 2.0—4.0,>80 mmol·L-1,= 40—160 mmol·L-1,reaction time 2 h.The changes of(COD/TOC)coag illustrated that the oxidation state of the organic matter removed by coagulation was significantly higher than in the fresh landfill leachate under the above reaction conditions.