Cu2+、Zn2+对生物脱氮系统的影响

Cu²⁺和Zn²⁺是污水处理工艺中经常遇到的金属离子。在驯化好的活性污泥系统中,研究了金属离子Cu²⁺和Zn²⁺在0～100 mg/L浓度下对活性污泥生物脱氮系统的影响。试验发现Cu²⁺＞5 mg/L、Zn²⁺＞30 mg/L时,对硝化过程具有明显的抑制作用,在同样浓度的试验条件下Cu²⁺对硝化过程的抑制作用比Zn²⁺大。Cu²⁺≤0.5 mg/L时对反硝化过程具有一定的促进作用,有助于提高TN的去除效果;Cu²⁺＞0.5 mg/L时,对反硝化产生抑制作用,随着浓度的增加,TN去除率逐渐下降。Zn²⁺不影响反硝化过程,仅在大于30 mg/L时,对硝化过程产生抑制作用。重金属Cu²⁺对生物脱氮系统的影响明显强于Zn²⁺。     

Dechlorination of carbon tetrachloride by the catalyzed Fe-Cu process

The electrochemical reduction characteristics of carbon tetrachloride (CT) were investigated using cyclic voltammetry in this study. In addition, the difference in reduction mechanisms of CT between Master Builders' iron and the catalyzed Fe-Cu process was discussed. The results showed that CT was reduced directly on the surface of copper rather than by atomic hydrogen produced at the cathode in the catalyzed Fe-Cu process. The reduction was realized largely by atomic hydrogen in Master Builders' iron. The entire CT in 350 ml aqueous solution with 320 mgL was reduced to trichloromethane and dichloromethane in 2.25 h when 100 g of scrap iron with FeCu ratio of 10:1 (ww) were used. Moreover, the reduction rate slowed with time. CT could be reduced at acidic, neutral and alkaline pH from solution by Fe-Cu bimetallic media, but the mechanisms were di?erent. The degradation rate was not significantly in?uenced by pH in the catalyzed Fe-Cu process; in Master Builders' iron it clearly increased with decreasing pH. The kinetics of the reductions followed pseudo-first order in both cases. Furthermore, the reductions under acidic conditions proceeded faster than that under the neutral and alkaline conditions. The catalyzed Fe-Cu process was superior to Master Builders' iron in treating CT-containing water and this advantage was particularly noticeable under alkaline conditions. The reduction was investigated in the cathode (Cu) and anode (Fe) compartments respectively, the results showed that the direct reduction pathway played an important role in the reduction by the catalyzed Fe-Cu process. The catalyzed Fe-Cu process is of practical value.     

京津冀一体化中河北省环境角色定位的构思

河北省的环境角色定位在于对外实现环境的自主性,对内实现环境的恢复和可持续性。而这一定位的难题是环境与经济如何兼得,具体来说就是河北省环境与自身经济、与京津发展、与一体化如何协调。破解经济与环境的博弈,河北省需要把握住自身的主体性,进而实现环境的自主性,规划一体化下的产业格局,促进产业结构的转型,发展低碳经济,最终实现发展模式的更新,而这一定位的最终实现则需要法制的落实和保障。     

政府在环保产业发展中的作用

本文立足于我国市场经济体制不完善的现实，指出发展我国环保产业，政府应发挥主导作用，并提出了促进我国环保产业发展的政策对策。     

Laboratory-scale study of the suppression of PCDD/F emission during coal and MSW co-incineration

The experimental test of co-incinerating Chinese raw municipal solid waste （MSW） and coal in a laboratory-scale tubular reactor was first reported in present study, and the emission of normal gas components and the effects of the S/Cl molar ratio or coal mixing percentages on polychlorinated dibenzo-p-dioxins and dibenzofurans （PCDDs/Fs） emission were investigated and discussed. The results indicated that OCDD was the only PCDD homologues since others like TCDD-HpCDD was hardly detected, while as the categories of PCDF homologues were comparatively much more general. The amount of PCDD was much larger than that of PCDF in all operating conditions. Since ZPCDF/∑PCDD〈〈1, the dominant role of the precursor formation was proven in our experimental conductions. With increasing the coal addition to MSW （from 0 to 16%）, PCDD and PCDF were reduced considerably. Coal and MSW may suppress the PCDD/F emissions efficiently （over 95%） during the MSW incineration process. The PCDD/F suppression results of the present study could be helpful guidance to the industrial application of Chinese MSW and auxiliary coal co-incineration processes. The PCDD/F stack emission data of two industrial incinerators using co-incineration technology in China seem to have a great positive reduction of PCDDs/Fs.     

雌二醇对生物体内分泌系统毒性作用机制的研究

雌二醇可扰乱生物体内激素的正常分泌,对生物体生殖发育、神经系统及免疫系统造成损伤。本文通过查阅大量文献,结合临床试验及动物试验,研究了雌二醇干扰生物体内分泌系统的作用机制,结果发现:持续大剂量的雌二醇可显著扰乱动物体的内分泌系统;脂溶性的雌二醇不易被降解,在人体内也没有特定的代谢途径,因此微量的雌二醇即可在体内蓄积进而对机体造成损伤。     

Pt-Cu/TiO2{001}纳米片用于CO2加氢制甲醇反应的研究

以高暴露{001}晶面的TiO₂纳米片为载体,利用共还原法负载0.5%的Pt和一定量的Cu得到Pt-Cu/TiO₂{001}催化剂,并在P=3.0 MPa,T=200~300℃,V（N₂）：V（H₂）：V（CO₂）=8：69：23,空速（WHSV）=3600 mL·g^-1·h^-1反应条件下评价了催化剂催化CO₂加氢制甲醇的反应性能.XRD、XPS、EPR和CO₂-TPD等的表征表明,与催化剂Cu/TiO₂相比,引入Pt后,催化剂由于金属Pt的电子促进作用使负载的金属与载体之间的相互作用更强,进而有利于稳定Cu颗粒尺寸且载体形成了更多缺陷（如氧空位、Ti³⁺）.因此,Pt-Cu/TiO₂{001}催化剂的金属与载体界面上的活性位点更多,从而表现出更好的CO₂活化能力和甲醇生成性能.     

企业在发展循环经济中的地位和作用

发展循环经济，建设节约型社会是当前的热点、难点问题。企业是发展循环经济的主体，它对于整个经济的可持续发展具有非常重要的作用，制定企业循环经济发展战略应该是整个经济增长中的重要环节。探讨了企业在发展循环经济中的主体地位，发展循环经济对企业的作用，分析了制约企业在循环经济中发挥作用的因素，最后提出了提高企业自身发展循环经济能力的措施。     

近20年来关于森林作用研究的进展

1981年和1982年著名地理学家黄秉维先生先后发表了两篇论文，题目是“确切地估计森林的作用”和“再谈森林的作用”。这两篇论文的发表，促进了关于森林作用的讨论，也促进了有关的实验和理论研究。直到今天，它对于我国的生态、环境建设，特别是在西部大开发中，仍有重要的现实意义。20年来，这个问题的一些方面在中国和世界范围内有了新的进展，而另外一些则仍有待进一步深入研究。其主要进展在实验科学和理论研究上都有体现。新的实验获得了更具有代表性和说服力的数据，而理论研究则把过去的工作作了进一步的梳理，经过细致的深入研究，一些问题也就迎刃而解了。但由于问题本身的复杂性和进行实验的难度，有不少问题的解决仍有待于进一步的研究。     

再生资源产业发展中市场机制的缺陷和对策

再生资源市场发展是再生资源产业发展的关键,但再生资源市场机制存在着一些缺陷,这些缺陷制约着再生资源市场的发展。政府应当针对再生资源市场的缺陷采取一定的对策,发挥杠杆作用,提高市场效率,但不应当支配市场主体的行为。政策的影响往往不会与政策设计的预期完全一致,在干预市场时依据一定的原则可以最大程度地减少不利影响,提高政策的积极作用。