零价铁修复受三氯乙烯污染地下水的实验研究

通过批实验和柱实验研究了三氯乙烯（TCE）初始浓度、四氯乙烯(PCE)等对零价铁去除三氯乙烯的影响,并建立了三氯乙烯降解的反应动力学方程。结果表明：（1）零价铁对TCE具有较好的降解效果,反应符合准一级反应动力学方程,表观反应速率常数随TCE浓度的增加而减小;（2）在铁粉充足的条件下,TCE初始浓度对降解效果影响不显著,且TCE去除率皆可达到90%以上;（3）PCE的存在抑制了TCE的脱氯反应。PCE和TCE共存时,TCE的最大去除率仅为64.2%;TCE脱氯反应的表观反应速率明显降低,反应半衰期由TCE单独存在时的6.8～9.7 h增大到66 h～346.5 h。     

微波诱导鳞片石墨-H2O2催化氧化处理甲基紫废水

研究微波诱导鳞片石墨-H2O2催化氧化处理甲基紫废水工艺,探讨各种因素的协同作用及对废水脱色效果的影响,并采用SEM、EDX、XRD和FTIR对新鲜及使用6次后的鳞片石墨进行表征。结果表明,微波诱导鳞片石墨-H2O2能高效快速降解废水中的甲基紫;在50mL初始pH为3,质量浓度为10mg／L的甲基紫废水中,H2O2用量1mL／L,鳞片石墨3g／L,微波输出功率259W,微波辐射时间9min的最佳处理工艺条件下,甲基紫脱色率达到了98．80％;微波、鳞片石墨、H2O2体系对甲基紫废水降解效果明显,产生协同效应。紫外-可见光谱分析表明,废水中甲基紫结构被破坏,但仍含有少量苯环等小分子。动力学研究表明,脱色反应符合一级反应动力学规律,反应速率常数^为0．42613min^-1,反应半衰期t。为1．626min。     

Characteristics of penicillin bacterial residue

A hybrid selective noncatalytic reduction/selective catalytic reduction (SNCR/SCR) system that uses two types of technology, low-temperature SCR process and SNCR process, was designed to develop nitrogen oxide (NO_x) reduction technology. SCR was conducted with space velocity (SV) = 2400 hr^?1 and hybrid SNCR/SCR with SV = 6000 hr^?1, since the study focused on reducing the amount of catalyst and both achieved 98% NO_x reduction efficiency. Characteristics of NO_x reduction by NH₃ were studied for low-temperature SCR system at 150 °C using Mn-V₂O₅/TiO₂ catalyst. Mn-added V₂O₅/TiO₂ catalyst was produced, and selective catalyst reduction of NO_x by NH₃ was experimented. NO_x reduction rate according to added Mn content in Mn-V₂O₅/TiO₂ catalyst was studied with varying conditions of reaction temperature, normalized stoichiometric ratio (NSR), SV, and O₂ concentration. In the catalyst experiment according to V₂O₅ concentration, 1 wt.% V₂O₅ catalyst showed the highest NO_x reduction rate: 98% reduction at temperature window of 200~250 °C. As a promoter of the V₂O₅ catalyst, 5 wt.% Mn was added, and the catalyst showed 47~90% higher efficiency even with low temperatures, 100~200 °C. Mn-V₂O₅/TiO₂ catalyst, prepared by adding 5 wt.% Mn in V₂O₅/TiO₂ catalyst, showed increments of catalyst activation at 150 °C as well as NO_x reduction. Mn-V₂O₅/TiO₂ catalyst showed 8% higher rate for NO_x reduction compared with V₂O₅/TiO₂ catalyst in 150 °C SCR. Thus, (5 wt.%)Mn-(1 wt.%)V₂O₅/TiO₂ catalyst was applied in SCR of hybrid SNCR/SCR system of low temperature at 150 °C. Low-temperature SCR hybrid SNCR/SCR (150 °C) system and hybrid SNCR/SCR (350 °C) showed 91~95% total reduction rate with conditions of SV = 2400~6000 hr^?1 SCR and 850~1050 °C SNCR, NSR = 1.5~2.0, and 5% O₂. Hybrid SNCR/SCR (150 °C) system proved to be more effective than the hybrid SNCR/SCR (350 °C) system at low temperature.

Implications:?NO_x control is very important, since they are the part of greenhouse gases as well as the cause of acid rain and ozone hole. A technology, so-called hybrid SNCR/SCR process, was tested using Mn-V₂O₅/TiO₂ monolithic catalyst for NO_x reduction, and the method is promising. The results of this study would provide some ideas to parties such as policy makers, environmental engineers, and so on.     

Gas-phase elemental mercury removal in a simulated combustion flue gas using TiO2 with fluorescent light

A previously proposed technology incorporating TiO₂ into common household fluorescent lighting was further tested for its Hg⁰ removal capability in a simulated flue-gas system. The flue gas is simulated by the addition of O₂, SO₂, HCl, NO, H₂O, and Hg⁰, which are frequently found in combustion facilities such as waste incinerators and coal-fired power plants. In the O₂ + N₂ + Hg⁰ environment, a Hg⁰ removal efficiency (η_Hg) greater than 95% was achieved. Despite the tendency for η_Hg to decrease with increasing SO₂ and HCl, no significant drop was observed at the tested level (SO₂: 5–300 ppm_v, HCl: 30–120 ppm_v). In terms of NO and moisture, a significant negative effect on η_Hg was observed for both factors. NO eliminated the OH radical on the TiO₂ surface, whereas water vapor caused either the occupation of active sites available to Hg⁰ or the reduction of Hg₀ by free electron. However, the negative effect of NO was minimized (η_Hg > 90%) by increasing the residence time in the photochemical reactor. The moisture effect can be avoided by installing a water trap before the flue gas enters the Hg⁰ removal system.

Implications: This paper reports a novel technology for a removal of gas-phase elemental mercury (Hg⁰) from a simulated flue gas using TiO₂-coated glass beads under a low-cost, easily maintainable household fluorescent light instead of ultraviolet (UV) light. In this study, the effects of individual chemical species (O₂, SO₂, HCl, NO, and water vapor) on the performance of the proposed technology for Hg⁰ removal are investigated. The result suggests that the proposed technology can be highly effective, even in real combustion environments such as waste incinerators and coal-fired power plants.     

Artificial and enhanced humification of soil organic matter using microwave irradiation

Microwave (MW) irradiation, a less energy-intensive irradiation technique, was employed to promote the changes in physicochemical properties of soil organic matter (SOM). MW was irradiated to forest soils for 10 min. Then, the physical and chemical properties of the SOM were analyzed with UV absorbance spectroscopy, Fourier transform infrared spectroscopy, elemental analysis, and size exclusion chromatography. Also, the SOM was fractionated into biopolymer, fulvic acid, and humic acid, and each fraction was analyzed quantitatively. These analyses revealed that the SOM became more aromatic and nonpolar, highly condensed, and macromolecular organic substances that possess a higher amount of functional groups found in highly humified substances than the original SOM as a result of the MW irradiation. The humification-like alteration of SOM property was attributable to the thermal cracking and to the radical reaction, particularly when the MW was irradiated along with activated carbon under the aerobic condition. The results of this study suggest that the artificial and enhanced property changes of SOM can be accomplished by MW irradiation on an engineering time scale, which can contribute to the successful soil and groundwater remediation practice.     

木粉/壳聚糖接枝丙烯酸-丙烯酰胺吸附树脂对二元重金属离子溶液中Pb^2＋的吸附

采用自制木粉/壳聚糖接枝丙烯酸-丙烯酰胺吸附树脂R1、R2、R3对二元金属离子Cu2＋/Pb2＋和Zn2＋/Pb2＋溶液中的吸附性能进行了较系统考察。Pb2＋离子溶液中存在竞争离子Cu2＋、Zn2＋时,随竞争离子浓度增加,3种吸附树脂R1、R2、R3对Pb2＋的吸附量明显下降,而竞争离子吸附量显著增加。二元溶液中各金属离子浓度相同时,3种树脂对竞争离子Cu2＋、Zn2＋的吸附量大于对Pb2＋的吸附量;各溶液中分别加入NaCl及NaNO3、尿素后,对Pb2＋离子的吸附量下降迅速。随吸附树脂用量增加,竞争离子Cu2＋、Zn2＋的吸附量逐渐减小,Pb2＋的吸附量在吸附树脂用量0.10 g/L（Zn2＋/Pb2＋溶液）或0.15 g/L（Cu2＋/Pb2＋溶液）时出现最大值。溶液pH值对树脂吸附性能有显著影响。3.0     

四环素高效降解酵母菌Trichosporon mycotoxinivoransXPY-10降解特性

Trichosporon mycotoxinivorans XPY-10是一株分离自抗生素制药厂的高效四环素降解酵母菌。为了建立该菌株降解四环素的适宜条件,分别研究了碳源、有机氮源、金属离子等营养物质及初始底物浓度、接种量、pH、温度、装液量、摇床转速等理化因素对菌体生长及四环素降解效率的影响。结果表明,菌株XPY-10生长的最适碳源和氮源分别为蔗糖和蛋白胨。在含有0.05% FeSO₄的培养基中,菌株XPY-10降解四环素的适宜条件为：接种量2%,pH 8,温度34℃,装液量100 mL（250 mL 三角瓶）,摇床转速180 r/min。在此条件下,菌株XPY-10在7 d内对初始浓度为600 mg/L的四环素降解率为83.63%。本菌株对养殖废水及制药废水中四环素的污染治理有一定的应用前景。     

Industrial metabolism of chlorine: a case study of a chlor-alkali industrial chain

Substance flow analysis (SFA) is applied to a case study of chlorine metabolism in a chlor-alkali industrial chain. A chain-level SFA model is constructed, and eight indices are proposed to analyze and evaluate the metabolic status of elemental chlorine. The primary objectives of this study are to identify low-efficiency links in production processes and to find ways to improve the operational performance of the industrial chain. Five-year in-depth data collection and analysis revealed that system production efficiency and source efficiency continued increasing since 2008, i.e., when the chain was first formed, at average annual growth rates of 21.01 % and 1.01 %, respectively. In 2011, 64.15 % of the total chlorine input was transformed into final products. That is, as high as 98.50 % of the chlorine inputs were utilized when other by-products were counted. Chlorine loss occurred mostly in the form of chloride ions in wastewater, and the system loss rate was 0.54 %. The metabolic efficiency of chlorine in this case was high, and the chain system had minimal impact on the environment. However, from the perspectives of processing depth and economic output, the case study of a chlor-alkali industrial chain still requires expansion.     

铁铈钛复合氧化物催化剂的制备及其选择性催化还原NO的性能

采用共沉淀法制备了一种新型催化剂——铁铈钛复合氧化物催化剂,研究了Fe掺加量、体积空速以及H2O和SO2的加入对其选择性催化还原NO性能的影响;采用XRD和SEM等手段对催化剂的结构和形貌进行了表征。表征结果显示,Fe的掺加使催化剂表面的颗粒更均匀,提高了催化剂的分散度。实验结果表明：以Ce（NO3）3,Fe（NO3）3?9H2O,TiOSO4?2H2O为原料、按n（Ce）∶n（Fe）∶n（Ti）=0.2∶0.8∶1配比制得的Ce0.2Fe0.8TiOx为催化剂,在反应温度250 ℃、反应时间3 h、体积空速25 000 h-1的条件下,NO去除率为99.8%,N2选择性为100%;Fe的掺加显著提高了Ce0.2Fe0.8TiOx催化剂的抗H2O和SO2的能力。     

Mechanistic and kinetic study on the ozonolysis of n-butyl vinyl ether, i-butyl vinyl ether and t-butyl vinyl ether

Density functional theory (DFT) and ab initio method are employed to elucidate the mechanisms for O(3)-initiated oxidation of n-butyl vinyl ether (n-BVE) and its isomers (i-BVE and t-BVE). For each BVE, the reactions proceed via O(3) cycloaddition resulting in the formation of primary ozonides (POZs) and then two self-decomposition pathways of POZs are followed. Major products are identified to be formaldehyde and butyl formates (CH(3)CH(2)CH(2)CH(2)OCHO for n-BVE, (CH(3))(2)CHCH(2)OCHO for i-BVE and (CH(3))(3)COCHO for t-BVE). The total and individual rate constants for main product channels have been calculated using the modified multichannel Rice-Ramsperger-Kassel-Marcus (RRKM) approach. At 298 K and 101 kPa, the calculated total rate constants are 2.50×10(-16), 3.41×10(-16) and 4.17×10(-16) cm(3) molecule(-1) s(-1) for n-BVE+O(3), i-BVE+O(3) and t-BVE+O(3), respectively, which are in perfect agreement with experimental results. The total rate coefficients are almost pressure independent in the range of 0.001-101 kPa but obviously positive temperature dependent over the whole study temperature range (200-400 K). Also, the favorable reaction pathways have been determined through the estimation of branching ratios. Moreover, the influence of alkoxy group structure on the reactivity of vinyl ethers was examined.