过硫酸钾去除水中的TCE

以地水中的氯代烃污染物三氯乙烯(TCE)为目标污染物,以过硫酸钾溶液为氧化剂,探讨了不同条件下过硫酸钾对TCE的去除效果。实验结果表明,在40℃,过硫酸钾初始浓度为2.43 g/L条件下,反应2 h后,TCE的去除率就可达到96.8%;过硫酸钾对TCE的去除符合一级反应动力学方程,速率常数(K)为1.3364 h-1,半衰期(t1/2)为0.51 h;过硫酸钾对TCE的去除速率在pH为中性附近时最大,其后无论pH升高或降低去除速率均减小;受温度和pH影响较明显,并且反应温度越高,受pH的影响越明显;随离子强度的增加而减小;反应活化能为119.6 kJ/mol;过硫酸钾溶于水生成过硫酸根离子(S2O28-),S2O28-会进一步生成硫酸根自由基(SO4-.),在碱性条件下,SO4-.与OH-反应会进一步生成羟基自由基(.OH)。过硫酸钾对于TCE的去除主要源自SO4-.和.OH的强氧化性。     

油田水反硝化技术抑制硫酸还原菌

利用反硝化技术对江苏油田5个联合站的采出水,进行了添加不同抑制剂的浓度、种类、不同配比和接种DNB菌对SRB、DNB的菌落数量、硫化氢的产生量和氧化还原电位的影响的静态实验。研究结果表明:投加一定浓度的硝酸盐、亚硝酸盐和钼酸盐,对油田采出水SRB的生长都有不同程度的抑制作用,而同等浓度的抑制效果表现为亚硝酸盐>硝酸盐>钼酸盐,同时投加DNB和0.3～0.5 g/L(比例为1∶1)的亚硝酸盐/硝酸盐可较好地抑制油田采出水中的SRB和硫化氢的产生,其中0.5 g/L抑制效果最明显,可抑制硫化氢的产生10 d以上,SRB和硫化氢抑制率分别可达87%和98%。以不同药剂的常压静态腐蚀实验结果表明,抑制剂的腐蚀速率比杀菌剂和缓蚀剂略高,但低于石油天然气行业中标准规定的0.0076 mm/a,也远低于对照样的0.152 mm/a。     

城市旅游综合体发展模式与对策研究

旅游综合体顺应了世界休闲业发展的潮流,它以旅游为主导,是一种全新的生产力形态。界定了城市旅游综合体的基本概念,归纳了城市旅游综合体的主要特征,探讨了城市旅游综合体形成的机制,认为旅游消费转型发展、地方特色文化传承、城市商业发展、旅游供给能力升级、政府的城市发展政策支持是城市旅游综合体形成的主要因素。依据城市旅游综合体发展的核心驱动功能不同,将城市旅游综合体的开发模式分为娱乐旅游综合体、休闲度假游综合体、会展旅游综合体和商业旅游综合体4种类型,在此基础上,提出了促进城市旅游综合体健康持续发展的对策。     

充分利用环保倒逼机制促进产业结构调整升级

淄博市污染聚集,环境质量易受外来因素影响,产业结构不合理,污染物排放量大,排放强度高。但其充分发挥环保的倒逼作用,通过建立健全环保政策法规体系,严格执行高于省及国家标准的地方环保标准,大力发展高新技术和现代服务业,加快改造传统产业,极大地促进了产业结构升级和经济发展方式的转变。     

Photocatalytic oxidation of monuron in the suspension of WO3 under the irradiation of UV-visible light

A comprehensive study of the degradation of monuron, one of the phenylurea herbicides, was conducted by UV-Vis/WO₃ process. It was found that hydroxyl radicals played a major role in the decay of monuron while other radicals (e.g. superoxide) and hole might also contribute to the decomposition of monuron. The oxidation path likely plays a major role in the generation of hydroxyl radicals. The effects of initial pH level, initial concentration of monuron, and inorganic oxidants on the performance of UV-Vis/WO₃ process were also investigated and optimized. Comparison between monuron decay pathways by UV-Vis/WO₃ and UV/TiO₂ was conducted. The decay mechanisms, including N-terminus demethylation, dechlorination and direct hydroxylation on benzene ring, were observed to be involved in the oxidation of monuron in these two processes. Sixteen intermediates were identified during the photodegradation of monuron and degradation pathways were proposed accordingly.     

Catalytic destruction of pentachlorobenzene in simulated flue gas by a V2O5-WO3/TiO2 catalyst

Pentachlorobenzene (PeCB) in simulated flue gas was destructed by a commercial V₂O₅-WO₃/TiO₂ catalyst in this study. The effects of reaction temperature, oxygen concentration, space velocity and some co-existing pollutants on PeCB conversion were investigated. Furthermore, a possible mechanism for the oxidation of PeCB over the vanadium oxide on the catalysts was proposed. Results show that the increase of gas hourly space velocity (GHSV) and the decrease of operating temperature both resulted in the decrease of PeCB removal over the catalyst, while the effect of the oxygen content in the range of 5-20% (v/v) on PeCB conversion was negligible. PeCB decomposition could be obviously affected by the denitration reactions under the conditions because of the positive effect of NO but negative effect of NH₃. The introduction of SO₂ caused the catalyst poisoning, probably due to the sulfur-containing species formed and deposited on the catalyst surface. The PeCB molecules were first adsorbed on the catalyst surface, and then oxidized into the non-aromatic acyclic intermediates, low chlorinated aromatics and maleic anhydride.     

The OH-induced degradation mechanism of 4-chloro-2-methylphenoxyacetic acid (MCPA) with two forms in the water: a DFT comparison

The initial degradation mechanisms of OH and 4-chloro-2-methylphenoxyacetic acid (MCPA) including molecular form and anionic form are studied at the MPWB1K/6-311+G(3df, 2p)//MPWB1K/6-31+G(d, p) level. Possible reaction pathways of H-atom abstraction and OH addition are considered in detail. By result comparison analysis, it is found that the reaction mechanisms for OH and two forms of MCPA are different, and most reactions for anionic MCPA are easier than those for molecular MCPA. For H-atom abstraction reactions, the calculated energies show that OH abstracting H-atom from -CH₃ group of molecular MCPA is the most kinetically favorable process; the potential energy surface for anionic MCPA indicates that H-atom in -CH₂ group is slightly easier to be abstracted than that in -CH₃ group. For OH addition reactions, the addition of OH to the C1 site is the initial step for molecular MCPA and the predominant product is 4-chloro-2-methylphenol (denoted P3), while the C4 site is the most reactive site for anionic MCPA and the primary product results from the hydroxylation of the aromatic ring, which is in good agreement with the experimental observation. In additional, results from PCM calculations show that most reactions in water phase are more kinetically favorable than those in gas phase, though the mechanisms discussed above will not be changed.     

磁性海泡石吸附Cr(VI)特性及动力学

采用化学共沉淀法合成磁性海泡石,通过静态吸附实验研究磁性海泡石对Cr(Ⅵ)的吸附特性及其动力学。结果表明,磁性海泡石对Cr(Ⅵ)的吸附在90 min内即可达到平衡;体系的初始pH是影响磁性海泡石吸附Cr(Ⅵ)性能的重要因素;当废水中Cr(Ⅵ)的初始浓度为50 mg/L时,磁性海泡石的适宜投加量为10 g/L;随反应温度的升高,磁性海泡石对Cr(Ⅵ)的吸附量增加;温度为25、35和45℃时,磁性海泡石对Cr(Ⅵ)的饱和吸附量分别为3.32、3.72、4.08 mg/g;吸附动力学曲线可以用拟二级反应动力学模型拟合;内扩散和液膜扩散联合控制Cr(Ⅵ)在磁性海泡石上的吸附过程,其中内扩散的控速作用大于液膜扩散。     

铁炭微电解法降解TAIC废水

TAIC（三烯丙基异氰脲酸酯）作为过氧化物交联或自由基反应交联的助交联剂被广泛应用。由于TAIC性质稳定难于生物降解,采用铁炭微电解法处理TAIC生产废水,并考察了铁炭比、进水pH值、反应时间对处理效果的影响,以及TAIC降解机理和反应动力学过程。结果表明,影响微电解工艺的因素主次关系为：pH>Fe/C质量比>反应时间;在最佳条件进水pH值为5,铁炭质量比为2：1,反应时间为135 min时,COD的去除率达到46%以上,TAIC的去除率达到48%以上。TAIC去除机理研究表明,微电解对TAIC废水的作用主要通过·H的还原和铁离子的絮凝作用,其中·H的还原作用是TAIC降解的主要原因。反应动力学分析表明,铁炭微电解法处理TAIC的降解过程基本符合二级反应动力学规律,通过建立模型并拟合出了TAIC降解的二级反应动力学方程。     

煤炭企业发展低碳经济的动力机制

将影响煤炭企业发展低碳经济的动力因素分为四大类,包括4个拉力因素、1个支撑因素、2个压力因素和4个推动力因素。设计了煤炭企业发展低碳经济的动力机制模型,在分析各个动力因素的基础上,构建了煤炭企业发展低碳经济的拉力机制模型、支撑机制模型、压力机制模型和推动力机制模型。