过氧化氢氧化亚甲基蓝褪色催化动力学光度法测定镍

在pH 8.00的NH₃-NH₄Cl缓冲溶液中,在100 ℃加热条件下,痕量镍能催化过氧化氢氧化亚甲基蓝的褪色反应,建立了测定痕量镍的催化动力学光度方法。研究发现,非催化反应吸光度(A₀)和催化反应吸光度(A)在655 nm处的差值ΔA与镍的质量浓度在0.01～0.30 μg/mL范围内呈良好的线性关系,方法检出限为8.6×10^-3 μg/mL。该催化反应的表观速率常数为8.2×10^-4 s^-1,表观活化能为66.08 kJ/mol。方法用于延河水和自来水厂污水中痕量镍的测定,测定值与原子吸收光谱法一致,相对标准偏差(RSD,n=6)为1.2%～1.6%,加标回收率为99%~102%。     

亚甲基蓝-高碘酸钾催化动力学光度法测定钼尾矿中钼

实验研究发现,在硫酸存在的情况下,高碘酸钾可以氧化亚甲基蓝褪色,钼对该褪色反应有催化作用,据此,建立了催化动力学光度法测定钼尾矿中钼的新方法。实验表明:当显色体系中亚甲基蓝浓度为0.012 g/L、硫酸浓度为0.001 mol/L、高碘酸钾浓度为0.000 4 mol/L时,于60 ℃加热13 min,钼在0.02～0.6 mg/L范围内与吸光度变化值呈良好的线性关系,方法检出限为0.05 mg/L。在最佳实验条件下,催化体系的表观活化能E_a=47.31 kJ/moL,反应速率常数k=3.5×10^-4/s。方法应用于3个不同地区钼尾矿中钼的测定,测定结果与原子吸收光谱法(AAS)吻合,相对标准偏差(RSD,n=11)为2.1%～2.9%,回收率为97%～102%。     

过氧化氢氧化亚甲基蓝褪色催化光度法测定铝合金中痕量镍

基于在pH 5.6的Na₃C₆H₅O₇-NaOH缓冲溶液中,痕量镍对H₂O₂氧化亚甲基蓝(MB)的褪色反应具有催化作用且褪色的程度与镍的含量成线性关系,建立了催化动力学光度法测定痕量镍的新方法。研究了影响催化褪色反应的因素,并测定了一些动力学参数。结果表明,非催化反应体系与催化反应体系的最大吸收波长均在664 nm处,方法的线性范围为0.02～1.4 μg/mL,线性回归方程为lg(A₀/A_t)=0.776 5 ρ(μg/mL)+0.157 1,相关系数r =0.998 6,检出限为0.011 8 μg/mL,反应的表观活化能为25.14 kJ/moL。方法用于铝合金标准样品中痕量镍的测定,结果与认定值基本一致,相对标准偏差(RSD)为2.9%和2.8%(n=5),回收率在98%～104%范围。     

氨基功能化磁性氧化石墨烯吸附亚甲基蓝的性能探讨

以改进的hummers法制备的氧化石墨烯为载体,采用共沉淀法制备出磁性氧化石墨烯,再以乙二胺修饰,制备出氨基功能化磁性氧化石墨烯(EDA-MGO)。通过傅里叶红外变换光谱(FI-IR)、扫描电子显微镜(SEM)和X射线衍射仪(XRD)对材料的官能团、表面形貌和结构组成进行表征,分析EDA-MGO的磁分离和回收性能,并探讨EDA-MGO对亚甲基蓝的吸附性能。结果表明,立方相纳米级磁性Fe₃O₄均匀负载于氧化石墨烯表面,氨基功能化成功,且EDA-MGO具有很好的磁分离和回收性能。室温下,当亚甲基蓝初始质量浓度为100mg/L、体积为100mL、吸附剂质量为0.07g、pH值为7、吸附时间为150min时,EDA-MGO对亚甲基蓝的吸附率和吸附量分别为97.56%和139.37mg/g,其吸附过程符合拟二级动力学模型和Langmuir等温吸附模型。吸附剂循环使用6次后,吸附量为108.33mg/g,表明EDA-MGO具有很好的再生循环使用能力。     

亚甲基蓝-高碘酸钾系统催化动力学光度法测定痕量钒(V)

在硫酸介质中,活化剂柠檬酸存在时,于90℃的加热条件下,痕量钒(V)灵敏地催化高碘酸钾氧化亚甲基蓝褪色的指示反应。探讨了最佳实验条件,测定了动力学参数,建立了测定痕量钒(V)的新光度分析方法。研究发现,非催化反应吸光度(A0)与催化反应吸光度(A)在659 nm处的差值ΔA与钒(V)的质量浓度ρ在0.004~0.06μg/mL范围内呈良好的线性关系,检出限为1.78×10-10g/mL。该催化反应为准一级反应,反应的表观速率常数为9.03×10-4/s,表观活化能为60.92 kJ/mol。方法用于炼钢烧结矿样品中痕量钒(V)的测定,其回收率在101%~102%的范围,符合痕量分析的要求。     

亚甲基蓝还原浸出低品位钴土矿

采用亚甲基蓝作为还原剂,在硫酸体系中直接浸出低品位钴土矿,考察了亚甲基蓝浓度、硫酸浓度、反应温度、反应时间等对浸出率的影响。结果表明,在下述最优条件下,钴土矿中钴和锰的浸出率可同时达到99%以上:硫酸初始浓度1.6mol/L,亚甲基蓝初始浓度5g/L,反应温度95℃,浸出时间4h,液固比3∶1。     

纳米氧化铜的制备及光催化降解亚甲基蓝

近年来,印染废水造成环境污染的问题日益严重。为处理印染废水,以亚甲基蓝(MB)为目标降解物,采用化学沉淀法制备出了纤维状和球状两种形貌的纳米氧化铜,利用XRD和SEM对样品进行表征。当催化剂投加量0.1 g、初始pH=9、亚甲基蓝初始浓度5 mg/L、质量分数为30%的H₂O₂滴加量1 mL、紫外光下反应75 min时,亚甲基蓝溶液降解率最高,且催化剂循环使用3次后,亚甲基蓝的降解率仍在88%以上,具有优良的稳定性。纳米氧化铜的形貌相同时,晶粒尺寸越小,对亚甲基蓝催化降解效果越好。相同条件下,球状纳米氧化铜催化降解亚甲基蓝的能力强于纤维状纳米氧化铜。     

芭蕉芋渣对亚甲基蓝的动态吸附研究

利用芭蕉芋渣填料柱对水中亚甲基蓝(MB)进行动态吸附.探讨了初始质量浓度、床层高度、pH值等因素对穿透曲线的影响,运用数学模型对在不同层高和质量浓度下的吸附数据进行拟合.结果表明,芭蕉芋渣能有效去除水中的亚甲基蓝,随着床层高度的增高、pH的增大和初始质量浓度的减小,芭蕉芋渣填料柱对水中亚甲基蓝的吸附穿透曲线位点向右移.通过数学模型得到的速率常数、相关系数、平衡吸附量和动力学参数,能较好地描述芭蕉芋渣填料柱吸附亚甲基蓝的吸附动力学.     

CuⅡ-H_2O_2-甲基蓝体系催化动力学光度法测定水中痕量铜的研究

研究了在0.1 mol/L H2SO4介质中,痕量Cu(催化过氧化氢氧化甲基蓝褪色反应的动力学条件,建立了催化动力学光度法测定铜的新方法。体系的最大吸收波长为560 nm,Cu(线性范围为0~0.08 mg/L,方法检出限为1.3×10-7g/L,用于水中痕量铜的测定,结果满意。     

La掺杂钼酸钴花状材料的制备及其降解印刷染料亚甲基蓝的研究

主要对钼酸钴花状结构材料的制备及其降解印刷染料亚甲基蓝展开研究。采用简单易操作的水热法进行钼酸钴花状结构材料和La掺杂的钼酸钴复合材料(La-CoMoO₄)实验制备,运用XRD、SEM、TEM方法对样品进行表征分析,研究了La掺杂对钼酸钴花状结构材料的光催化性能和稳定性的影响。结果表明,实验中制备的La-CoMoO₄呈现均匀的花状结构,无其他杂质峰和杂质元素存在,纯度较高。催化降解有机染料亚甲基蓝的实验结果表明,La掺杂使钼酸钴光催化降解亚甲基蓝的能力得到显著提升,经过40 min降解,染料降解率可以提高到98%,La掺杂同未掺杂相比,提高近25%的降解率,数据表明,光催化活性循环20次后,没有明显衰减,说明La-CoMoO₄具有很好的稳定性,可以重复多次利用。     

深海锰结核作生物固定化载体处理染料废水

用深海锰结核作生物固定化载体,在气升式反应器内进行广对比实验．结果表明：结核作固定化载体处理废水,可有效地降低废水中的化学耗氧量（COD）、生物耗氧量（BOD）、固体悬浮物（SS）、色度等,并可打开难降解的苯环．固定化微生物脱色机理是载体吸附和细菌降解双重作用．处理后的污水可作为J13菌的有效营养和碳源,作为微生物浸出深海锰结核中有价金属的培养基．固定化微生物在染料废水处理中有实用价值．     

Factors Affecting Effectiveness and Efficiency of DNAPL Destruction Using Potassium Permanganate and Catalyzed Hydrogen Peroxide

This paper describes laboratory studies conducted to evaluate the impact of varying environmental conditions (dense nonaqueous phase liquid (DNAPL) type and mass, and properties of the subsurface porous media) and design features (oxidant type and load) on the effectiveness and efficiency of in situ chemical oxidation (ISCO) for destruction of DNAPL contaminants. Porous media in 160?mL zero-headspace reactors were employed to examine the destruction of trichloroethylene and perchloroethylene by the oxidants potassium permanganate and catalyzed hydrogen peroxide. Measures of oxidation effectiveness and efficiency include (1) media demand (mg-oxidant/kg-porous media), (2) oxidant demand (mol-oxidant/mol-DNAPL), (3) reaction rate constants for oxidant and DNAPL depletion (min?1), (4) the percent (%) DNAPL destroyed, and (5) the relative treatment efficiency, i.e., the rate of oxidant depletion versus rate of DNAPL destruction. While an obvious goal of ISCO for DNAPL treatment is high effectiveness (i.e., extensive contaminant destruction), it is also important to focus on oxidation efficiency, or to what extent the oxidant is utilized for contaminant destruction instead of competing side reactions, for improved cost effectiveness and/or treatment times. Results indicate that DNAPL contaminants can be treated both effectively and efficiently under many environmental and design conditions. In some cases, DNAPL treatment was more effective and efficient than dissolved/sorbed phase treatment. In these experiments, permanganate was a more effective oxidant, however catalyzed hydrogen peroxide treated contaminants more efficiently (e.g., less oxidant required per mass contaminant treated). Results also indicate that oxidation treatment goals can be dictated by environmental conditions, and that specific treatment goals can dictate remediation design parameters (e.g., faster contaminant destruction was realized in catalyzed hydrogen peroxide systems, whereas greater contaminant destruction occurred in permanganate systems).     

过氧化氢湿法处理锰银矿工艺研究

介绍了利用过氧化氢浸锰-氰化浸银新工艺处理锰银矿的工艺研究。当控制锰浸出率96％时，银的浸出损失率＜2％；浸锰渣采用氰化法提银，NaCN用量1kg／t渣、浸出时间6h，银浸出率达94．96％。浸锰-氰化两步浸出银的回收率大于93％。     

Oxidative Decolorization of Reactive Dye Solution Using Fly Ash as Catalyst

This paper deals with the potential of coal fly ash as a heterogeneous catalyst in peroxidative decolorization of aqueous solution of several reactive drimarene dyes using hydrogen peroxide (H2O2). The effects of various parameters (source of fly ash, fly ash loading, temperature, pH, initial concentration of dye and hydrogen peroxide, and deactivation of catalytic effect of fly ash) were studied. The rate of decolorization is zero order with respect to concentration of dye in the range of 50–200 mg∕L and first order with respect to concentration of H2O2 in the range of 375–2,500 mg∕L. It was found that at 333 K and pH 2.0, only 2% (weight/volume) fly ash loading can completely decolorize 100 mg∕L dye solution within 180–1,770 s for an initial H2O2 concentration of 1,500 mg∕L, depending on the source of fly ash and dye used. But maximum 25% decolorization was noticed after 3 h duration of reaction without fly ash. The negligible homogeneous catalytic action of trace amount of metals like Fe, Mn, and Cu leached from the fly matrix confirmed the sole heterogeneous catalytic nature of fly ash particles in decolorization reactions. The deactivation of fly ash was found to be <30% in nine repeated uses. Adsorption dynamics and mechanism of dyes onto fly ash also were studied in the absence of H2O2.     

三氧化钨直接催化氧化四氢苯酐合成丁烷四羧酸

以三氧化钨为催化剂,无需有机溶剂、酸性配体及相转移剂,用30%H2O2为氧化剂氧化四氢苯酐(THPA)直接合成1,2,3,4-丁烷四羧酸(BTCA)即可达到较高的产率和纯度,反应结束后通过简单的过滤分离方法即可实现产物与催化剂分离目的。当(WO3)∶(环己烯)∶(H2O2)的摩尔比为1∶80∶352时,在回流温度下反应6h,己二酸分离产率为85%,产品纯度可达到98%。生产工艺简单,无污染,操作成本低。     

Gold Extraction from an Oxide Ore by Thiourea Leaching with Hydrogen Peroxide as an Oxidant

Russian Journal of Non-Ferrous Metals - In this study, the effects of thiourea (CH4N2S) on the efficiency of gold dissolution were investigated for the extraction of gold from an oxide gold ore of...     

Enhancement of Gold Heap Leaching by Using a Reagent Complex Containing Hydrogen Peroxide

Metallurgist - The paper provides a theoretical justification of the key chemical aspects of enhancing the process of heap leaching (HL) of gold by using a reagent complex containing hydrogen...     

分段浸出氧化锰矿和碳酸锰矿工艺研究

对氧化锰矿与碳酸锰矿浸出相结合的分段浸出工艺进行研究。考察硫酸浓度、葡萄糖用量、反应温度、时间和液固比等对两段锰浸出率及浸出液余酸的影响。结果表明,在还原浸出氧化锰矿阶段,采用葡萄糖占氧化锰矿的质量比6.33%、硫酸浓度4.37 mol/L、液固比1.5、90℃反应3h,锰浸出率为93.7%;在第二浸出阶段,加入剩余阳极液及1.5倍氧化锰矿质量的碳酸锰矿,在液固比6、90℃继续反应3h时,总锰浸出率达96.1%,浸出液余酸值降为9.4g/L。     

利用云南锰矿资源生产中碳锰铁的工业化实践

叙述了利用摇炉法应用云南锰矿生产中碳锰铁的工业化实践，它的成功有利于有效利用我省的高硅锰矿资源。     

Kinetic Modeling of the Gas-Phase Oxidation of Nitric Oxide Using Hydrogen Peroxide

The use of hydrogen peroxide (H2O2) to enhance the oxidation of nitric oxide (NO) under postflame conditions in the presence or absence of sulfur dioxide (SO2) has been studied by means of chemical kinetic modeling and compared with pilot-scale experimental data. The experimental results were obtained from a nonisothermal reactor at atmospheric pressure with inlet temperatures in the range of 770–790?K. The CHEMKIN-II model with a kinetic mechanism from the literature was employed for this work. At the temperatures studied, H2O2 produces OH and HO2 radicals which enhance the oxidation of NO. The OH radical also helps oxidize SO2. The modeling results confirmed an optimum temperature of about 775?K where the NO conversion reached about 90% with an H2O2:NO molar ratio of 1:1. Conversion of NO2 to HNO3 was found to occur to a slight extent. Finally, the presence of SO2 was found to promote slightly the oxidation of NO to NO2.