Degradation of 2,4-dichlorophenoxyacetic acid in water by ozonehydrogen peroxide process

This study reports an investigation into the degradation of 2,4-dichlorophenoxyacetic acid in bubble contactor column by O2/H2O2 process, which is widely used as a principal advanced oxidation process. The degradation of 2,4-dichlorophenoxyacetic acid was studied under different H202/O3 molar ratio and pH value. Meanwhile, TOC removal was investigated both in distilled water and tap water. The influences of ozone transfer and consumed hydrogen peroxide were also discussed. The degradation products and oxidation intermediates were identified by GC-MS and LC-MS. A possible reaction mechanism was thus proposed.

Computer Data Processing of the Hydrogen Peroxide Decomposition Reaction

Two methods of computer data processing, linear fitting and nonlinear fitting, are applied to compute the rate constant for hydrogen peroxide decomposition reaction. The results indicate that not only the new methods work with no necessity to measure the final oxygen volume, but also the fitting errors decrease evidently.

UV-Catalytic Treatment of Municipal Solid-Waste Landfill Leachate with Hydrogen Peroxide and Ozone Oxidation

The performance of UV/H_2O_2, UV/O_3, and UV/H_2O_2/O_3 oxidationsystems for the treatment of municipal solid-waste landfill leachatewas investigated. Main objective of the experiment was to removetotal organic carbon (TOC), non-biodegradable organic compounds(NBDOC) and color. In UV/H_2O_2 oxidation experiment, with theincrease of H_2O_2 dosage, removal efficiencies of TOC and coloralong with the ratio of biochemical oxygen demand (BOD) to chemicaloxygen demand (COD) of the effluent were increased and a betterperformance was obtained than the system H_2O_2 alone.

Hydrogen peroxide and applications in green hydrocarbon nitridation and oxidation

Basic organic chemicals and high value–added products are mainly produced by hydrocarbon nitridation and oxidation.However,several drawbacks limit the application of the traditional oxidation and nitridation technologies in the future,such as complex processes,poor intrinsic safety,low atom utilization,and serious environmental pollution.The green nitridation and oxidation technologies are urgently needed.Hydrogen peroxide,a well–known green oxidant,is widely used in green hydrocarbon oxidation and nitridation.But its industrial production in China adopts fixed–bed technology,which is fall behind slurry–bed technology adopted by advanced foreign chemical companies,limiting the development of hydrogen peroxide industry and green hydrocarbon nitridation or oxidation industry.This article reviews the industrial production technologies of hydrogen peroxide and basic organic chemicals such as caprolactam,aniline,propene oxide,epichlorohydrin,phenol,and benzenediol,especially introduces the green production technologies of basic organic chemicals related with H_(2)O_(2).The article also emphasis on the efforts of Chinese researchers in developing its own slurry–bed technology of hydrogen peroxide production,and corresponding green hydrocarbon nitridation or oxidation technologies with hydrogen peroxide.Compared with traditional nitridation or oxidation technologies,green production technologies of caprolactam,propene oxide,epichlorohydrin,and benzenediol with hydrogen peroxide promote the nitrogen atom utilization from 60%to near 100%and the carbon atom utilization from 80%to near 100%.The waste emissions and environmental investments are reduced dramatically.Technological blockade against the green chemical industry of China are partially broken down,and technological upgrade in the chemical industry of China is guaranteed.

Removal of Basic Blue 9 Dye by Hydrogen Peroxide Activated by Electrogenerated Fe²⁺/Fe³⁺and Simultaneous Production of Hydrogen

Electrochemical techniques were used to oxidize organic pollutants by Fenton process using a mix of H2O2 and ferrous ions at a parallel plate reactor. The first stage was to build a micro scale reactor comprising two compartments, cathode and anode, separated by a membrane (Nafion-117). Each compartment has inlets and outlets to allow the flow of fluids (10 Lmin-1). The function of the reactor is to oxidize organic pollutants as well as to produce H2. Hydrogen is electrogenerated in the catholyte by the reduction of protons on a carbon steel cathode in acidic medium (0.05 M H2SO4). At the same time, a mixture of Fe2+/Fe3+ ions is produced in the anolyte (0.05 M Na2SO4, pH ≈ 2) by means of the oxidation of a sacrificial electrode made of stainless steel mesh. Fe2+/Fe3+ ions interact with H2O2 to generate strong oxidants which are responsible for oxidizing the organic matter and removing color. A voltage of 1 V was applied between the electrodes and remained constant, while the current observed was approximately 0.06 A. Under these conditions, the activation rate with different H2O2 concentrations (15, 20, 25, 30, 35, 40, 45 and 50 mM) was evaluated. The maximum activation rate (1.3 mM·min-1) was obtained using 30 mM H2O2. Under these conditions, the oxidation of a synthetic industrial effluent (0.615 mM BB9) was performed and the following results were obtained: 95% of this concentration was removed in 5 minutes and 15 mL of H2 was electrogenerated in 30 minutes.

UV-Based Advanced Oxidation Processes for Antibiotic Resistance Control: Efficiency, Influencing Factors, and Energy Consumption

Antibiotic resistant bacteria(ARB)with antibiotic resistance genes(ARGs)can reduce or eliminate the effectiveness of antibiotics and thus threaten human health.The United Nations Environment Programme considers antibiotic resistance the first of six emerging issues of concern.Advanced oxidation processes(AOPs)that combine ultraviolet(UV)irradiation and chemical oxidation(primarily chlorine,hydrogen peroxide,and persulfate)have attracted increasing interest as advanced water and wastewater treatment technologies.These integrated technologies have been reported to significantly elevate the efficiencies of ARB inactivation and ARG degradation compared with direct UV irradiation or chemical oxidation alone due to the generation of multiple reactive species.In this study,the performance and underlying mechanisms of UV/chlorine,UV/hydrogen peroxide,and UV/persulfate processes for controlling ARB and ARGs were reviewed based on recent studies.Factors affecting the process-specific efficiency in controlling ARB and ARGs were discussed,including biotic factors,oxidant dose,UV fluence,pH,and water matrix properties.In addition,the cost-effectiveness of the UV-based AOPs was evaluated using the concept of electrical energy per order.The UV/chlorine process exhibited a higher efficiency with lower energy consumption than other UV-based AOPs in the wastewater matrix,indicating its potential for ARB inactivation and ARG degradation in wastewater treatment.Further studies are required to address the trade-off between toxic byproduct formation and the energy efficiency of the UV/chlorine process in real wastewater to facilitate its optimization and application in the control of ARB and ARGs.

Degradation of p-nitrotoluene by O_3/H_2O_2 process and oxidation mechanism

The degradation of p-nitrotoluene by O3/H2O2 process in a bubble contact column was investigated. Effects of the molar ratio of hydrogen peroxide to ozone,pH value and t-butanol on the oxidation process were discussed. It was found that the proper H2O2/O3 molar ratio for the degradation of p-nitrotoluene was around 0.6, different pH values and the presence of t-butanol highly influenced the removal efficiency of p-nitrotoluene. 5-methyl-2-nitrophenol, 2-methyl-5-nitrophenol, (4-nitrophenyl) methanol, 5-(hydroxymethyl)-2-nitro phenol, acetic acid, 2-methylpropane diacid and 2-(hydroxylmethyl)propane diacid were identified as degradation intermediates and products through GC-MS. Radical reaction mechanism and degradation pathway were proposed based on the results of experiments. It is deduced that the benzene ring of p-nitrotoluene can be only destroyed by hydroxyl radicals through a polyhydroxy intermediate pathway. Then unstable polyhydroxy intermediates can be oxidized to different acids with low molecular weight rapidly.

魔芋多糖基活化剂在棉织物低温漂白中的应用

以自制魔芋多糖基活性剂作为棉织物过氧化氢低温漂白助剂,研究漂白工艺条件对漂白效果的影响,优化漂白工艺并阐述其活化机理。结果表明,优化漂白工艺为:活化剂4 g/L,NaOH 50 mmol/L,温度70℃,时间60 min;漂白活化剂能促进羟基自由基(HO·)的产生,有效降低漂白温度。成本计算结果表明,使用漂白活化剂能从试剂消耗和能源消耗两方面显著降低生产成本。

油炸花生仁品质特性分析

为筛选适合油炸加工的花生品种,以3个高油酸品种花育9111、花育917、花育910和两个普通油酸品种花育33号、花育50号为供试品种,以传统出口型大花生品种花育22号为对照,研究6个品种在油炸加工后,其感官品质、理化特性、风味物质、氧化稳定性等方面的差异。结果表明,高油酸花生油炸花生仁的总体喜欢度略好于花育22号。3个高油酸花生品种的油炸仁的棕榈酸、亚油酸、花生酸及山嵛酸含量均极显著低于普通油酸花生,油酸与花生烯酸含量均极显著高于普通油酸花生。TPA分析表明,花育910的酥脆性较好。预测的花育9111、花育917、花育910、花育33号、花育50号油炸花生仁货架期分别是花育22号的3.09、2.36、1.87、1.02、1.06倍。TOPSIS综合分析表明,花育9111>花育910>花育917>花育33号>花育50号>花育22号,3个高油酸花生油炸仁加工品质优于普通油酸花生。本研究表明高油酸花生可替代传统大花生用于油炸花生生产,这将为口感好、营养高、耐贮藏的花生品种的培育提供理论依据。

蒽醌法制过氧化氢技术研究进展

简单介绍了过氧化氢性质,重点介绍了近年来蒽醌法生产过氧化氢工艺在氢化工序、氧化工序、萃取工序、后处理工序的技术进步,并对其未来发展进行了展望。

H_(2)O_(2)对O_(3)-PMS体系降解碘帕醇的效能优化

碘化造影剂(ICMs)作为一种典型的药品和个人护理品(PPCPs)广泛应用于医疗行业,常规的水处理工艺很难将其有效去除,而目前报道中多采用的高级氧化工艺也仍存在不足.以碘帕醇(IPM)为例,通过实验模拟研究O_(3)、O_(3)-PMS、O_(3)-PMS-H_(2)O_(2)3种高级氧化体系的降解规律及消毒副产物生成情况,探究了H_(2)O_(2)浓度、初始pH、氯离子、碳酸氢根离子、有机质对IPM降解效果的影响,并对IPM的可能降解途径进行了分析.结果表明,在O_(3)-PMS体系中投加H_(2)O_(2)可以提升对IPM的降解效率,还能减少溴酸盐的产生;O_(3)-PMS-H_(2)O_(2)体系在不同pH条件下对IPM均表现出良好的降解效果;Cl^(-)、天然有机质的存在对O_(3)-PMS-H_(2)O_(2)体系均具有抑制作用;CO_(3)^(2-)/HCO_(3)−形成缓冲体系则可以显著促进IPM的降解;O_(3)-PMS-H_(2)O_(2)体系可以通过强氧化作用和取代脱碘的路径将IPM进行有效降解.本研究可以为ICMs污染水体的修复提供理论依据.

蒽醌法生产过氧化氢工艺危险性分析

通过梳理蒽醌法过氧化氢的生产工艺,将生产过程按单元进行划分,逐步分析出过氧化氢生产过程中的可能危险性,并剖析风险产生的原因,在此基础上提出了蒽醌法过氧化氢生产工艺危险的可行性防控措施。

车前草黄酮提取优化及其对过氧化氢损伤肝细胞的保护作用

目的通过响应面法优化富含车前子苷的车前草黄酮提取工艺,并探究车前草黄酮对过氧化氢(H_(2)O_(2))损伤的L02细胞的保护作用及其作用机制。方法通过单因素研究乙醇浓度、提取温度、液料比对车前草黄酮得率及其中车前子苷转移率的影响,在此基础上使用Central-Composite中心组合试验设计和响应面分析法筛选出车前草黄酮提取得率最高,车前子苷转移率最大的提取条件。通过测定该车前草黄酮对过氧化氢诱导的人正常肝细胞L02存活率、细胞凋亡、线粒体膜电位的影响,及其对L02细胞丙二醛(MDA)、谷胱甘肽(GSH)、过氧化物歧化酶(SOD)含量,HO-1、Nrf2、SOD蛋白表达量的影响来探究车前草黄酮对过氧化氢损伤的L02细胞的保护作用。结果研究结果表明,提取温度80℃、乙醇浓度65%、液料比为15∶1时,提取得到的车前草黄酮得率和车前子苷转移率均最大,分别为1.82%和35.01%。该条件下提取得到的车前草黄酮在25~100μg·mL^(-1)内可明显降低过氧化氢损伤的L02细胞的凋亡率(P<0.001),降低其线粒体膜电位损伤程度(P<0.001),增加细胞内SOD和GSH的表达量(P<0.001),降低细胞中MDA含量(P<0.01,P<0.001)。此外,该车前草黄酮可以调节过氧化氢损伤的L02细胞中HO-1、Nrf2、SOD的表达量,降低过氧化氢损伤肝细胞中HO-1、Nrf2蛋白表达水平,并增加细胞中SOD蛋白的表达量(P<0.05,P<0.01)。结论使用响应面法筛选出的车前草黄酮提取工艺操作简便,关键有效成分车前子苷的含量丰富,可为车前草黄酮的实际生产提供参考。该方法提取得到的车前草黄酮可降低过氧化氢损伤的肝细胞的氧化应激水平,对L02细胞具有一定的氧化损伤保护作用,研究结果可以为车前草黄酮作为护肝保健品的开发应用奠定基础。

Suppressing a mitochondrial calcium uniporter activates the calcium signaling pathway and promotes cell elongation in cotton

Mitochondrial calcium uniporter(MCU)is a conserved calcium ion(Ca^(2+))transporter in the mitochondrial inner membrane of eukaryotic cells.How MCU proteins regulate Ca^(2+)flow and modulate plant cell development remain largely unclear.Here,we identified the gene GhMCU4 encoding a MCU protein that negatively regulates plant development and fiber elongation in cotton(Gossypium hirsutum).GhMCU4expressed constitutively in various tissues with the higher transcripts in elongating fiber cells.Knockdown of GhMCU4 in cotton significantly elevated the plant height and root length.The calcium signaling pathway was significantly activated and calcium sensor genes,including Ca^(2+)dependent modulator of interactor of constitutively active ROP(GhCMI1),calmodulin like protein(GhCML46),calciumdependent protein kinases(GhCPKs),calcineurin B-like protein(GhCBLs),and CBL-interacting protein kinases(GhCIPKs),were dramatically upregulated in GhMCU4-silenced plants.Metabolic processes were preferentially enriched,and genes related to regulation of transcription were upregulated in GhMCU4-silenced plants.The contents of Ca^(2+)and H_(2)O_(2)were significantly increased in roots and leaves of GhMCU4-silenced plants.Fiber length and Ca^(2+)and H_(2)O_(2)contents in fibers were significantly increased in GhMCU4-silenced plants.This study indicated that GhMCU4 plays a negative role in regulating cell elongation in cotton,thus expanding understanding in the role of MCU proteins in plant growth and development.

工业装置蒽醌加氢钯催化剂活性下降原因分析及处理措施探讨

简单介绍了过氧化氢生产工艺,重点介绍了可能造成钯催化剂活性下降的原因,如工作液水分高、氧化铝粉覆盖、钯催化剂结块等,通过增加工作液除水设备、增加活性氧化铝旁滤系统、使用高性能钯催化剂等工艺调整措施,可以使钯催化剂活性逐渐恢复。

铁铜双金属复合类Fenton催化剂的制备及用于处理阿莫西林模拟废水研究

针对粉末状类Fenton催化剂难以回收再利用的难题,采用煅烧法制备球形铁铜双金属复合催化剂,优化了催化剂制备条件(成分配比、煅烧条件和氮气流量),表征了催化剂的表面形态,考查了阿莫西林降解动力学,探讨了催化剂催化机理,并利用以该催化剂为核心的类Fenton催化体系处理阿莫西林模拟废水。反应在最优条件下阿莫西林去除率可达到99.9%。

蒽醌法制过氧化氢工艺中烷基蒽醌加氢反应的研究进展

从反应机制、活性组分结构、水分影响加氢的机理3个方面,综述了近几年烷基蒽醌加氢反应的相关研究成果,并指出了未来烷基蒽醌加氢反应的研究方向。

基于动态贝叶斯网络的蒽醌法制备双氧水工艺风险评估

为降低因蒽醌法制备双氧水而引起的火灾爆炸风险,从蒽醌法制备双氧水工艺中选取危险性较大的萃取净化工序展开风险评估。首先,分析该工序的危险源,采用Freefta软件建立事故树模型,在该模型的基础上使用GeNIe软件绘制事故树转换的动态贝叶斯网络模型;然后,运用专家打分法和模糊分析法计算模型中基本事件的先验概率,运用GeNIe软件在设定的前置条件下计算模型中基本事件的后验概率;最后,比较先验、后验概率之间的变化幅度,确定重要基本事件,揭示引起火灾爆炸的危险源并制定应急处置技术。结果表明:降解物与杂质造成污染、工艺副反应产生并增多、催化剂失效以及双氧水自身化学性质活跃4种重要危险源对萃取净化工序火灾爆炸影响最大;从阻止火灾蔓延与液体疏通的角度针对重要危险源制定应急处置技术效果较好。

双氧水工艺安全研究与设计

蒽醌法制备过氧化氢是目前工业上常用的制取过氧化氢的方法,其技术比较成熟,过氧化氢生产过程自身存在着很大的风险,并在生产过程中出现了许多安全事故。本文将蒽醌法制备双氧水生产作为基础,对双氧水工艺展开了论述,分析了其工艺危险有害因素和关键设备危险性,总结出了重点工艺的安全控制设计,为其全面提高工艺安全水平提供了一些建议和参考。

南方红豆杉籽油的脱色工艺优化及其品质分析

对南方红豆杉籽毛油进行脱色。以脱色率为指标,先筛选出最佳脱色剂,然后在单因素试验的基础上,通过正交试验优化脱色工艺,并对脱色前后的南方红豆杉籽油的品质进行对比分析。结果表明:最佳脱色工艺为脱色时间60 min、脱色温度70℃、活性炭用量2%(以南方红豆杉籽毛油质量为基准)。在此条件下,脱色率可达74.42%±1.13%,酸价由0.31 mg/g降低至0.26 mg/g、过氧化值由0.127 g/100 g降低至0.097 g/100 g。脱色处理对南方红豆杉籽油中脂肪酸的组成及相对含量影响较小。