基于博弈论的南四湖流域生态补偿理论分析

采用博弈论的分析方法寻找南四湖流域生态补偿主客体的纳什均衡。在静态博弈模型和动态博弈模型得出两个截然不同的均衡：静态博弈的均衡是（不保护,不补偿）,动态博弈的均衡是（保护,补偿）。在静态博弈中进行激励设计,提高补偿客体保护水资源的积极性,实现帕累托最优,应该立法,制定严格的惩罚标准;动态分析是建立在完全信息的基础上,由此要求政府建立良好的信誉,才能保证均衡的长久,从而达到保护南四湖流域生态环境的目的。     

Cytotoxicity and DNA damage of five organophosphorus pesticides mediated by oxidative stress in PC12 cells and protection by vitamin E

Previous studies have demonstrated that pesticides could induce cytotoxicity and genotoxicity in vivo and in vitro, and that oxidative stress may be an important factor involved. However, investigations comparing the capability of different organophosphorous (OP) compounds to induce cytotoxicity, genotoxicity and oxidative stress are limited. Hence, the aim of this paper was to access the cytotoxic and genotoxic effects of five OPs or metabolites, Acephate (ACE), Methamidophos (MET), Chloramidophos (CHL), Malathion (MAT) and Malaoxon (MAO), and to clarify the role of oxidative stress, using PC12 cells. The results demonstrated that MET, MAT and MAO caused significant inhibition of cell viability and increased DNA damage in PC12 cells at 40 mg L(-1). MAO was more toxic than the other OPs. ACE, MET, MAT and MAO increased the levels of intracellular reactive oxygen species (ROS) and malondialdehyde (MDA), and decreased the activity of superoxide dismutase (SOD), catalase (CAT) and glutathione (GSH) at 20 mg L(-1) and 40 mg L(-1) to different degrees. Pre-treatment with vitamin E(600 μM)caused a significant attenuation in the cytotoxic and genotoxic effect; pre-treatment reversed subsequent OP-induced elevation of peroxidation products and the decline of anti-oxidant enzyme activities. These results indicate that oxidative damage is likely to be an initiating event that contributes to the OP-induced cytotoxicity.     

Optimization of ethylenediamine-grafted multiwalled carbon nanotubes for solid-phase extraction of lead cations

Introduction  

Ethylenediamine-grafted multiwalled carbon nanotubes (MWCNTs-EDA-I and MWCNTs-EDA-II) are optimized and employed to investigate the preconcentration of lead ions (Pb(II)) in trace level.     

深圳笔架山水厂优化节水的实验研究

针对目前我国城镇需水量大、原水费用高的问题,大多数水厂通过降低自用水量的方式节约水资源。经过在笔架山水厂进行的生产性实验,优化耗水工艺的运行条件,挖潜了该水厂的节水空间,自用水量降低。优化后,全处理系统可节约水资源76.83万m3/a,耗水率由原来的2.08%下降到1.49%,同时水厂的经济效益也得到了显著提高,优化后可在原来的基础上节约运行成本近60万元/a。     

好氧MBR处理垃圾渗滤液中膜面优势污染物及污染阻力

将好氧MBR处理垃圾渗滤液装置中的污泥混合液进行合理分离,通过死端过滤实验和膜污染阻力测定实验,以确定MBR中造成膜污染的优势污染物和优势污染阻力。实验结果表明,上清液中的胶体物质和大分子粘性有机物是造成膜污染的优势污染物;膜污染阻力主要由凝胶极化阻力和外部污染阻力构成,二者之和占总污染阻力的95%以上。     

温度对改性矿物吸附剂脱除气态汞影响

以蛭石、丝光沸石、膨润土及经改性后各物质为吸附剂,N2气氛下,在固定床实验台上进行了对烟气中单质汞脱除的实验研究,主要考察了温度的改变对改性矿物吸附剂脱除气态汞的影响。研究结果显示,膨润土、蛭石对汞的吸附基本不受温度的影响;未改性的吸附剂对汞的吸附能力均比较差;温度的提高有利于改性吸附剂对单质汞的脱除,说明改性后的吸附剂的脱汞过程以化学吸附为主;真正起作用的活性组分CeO2占据了丝光沸石的大部分表面积和空隙;丝光沸石经CuO改性前后吸附能力几乎未发生变化。     

强化混凝-吸附预处理生活污水

采用混凝/吸附复配的方式对生活污水进行了浓缩预处理。通过对有机物去除率和混合絮体沉降性能的考察,优选出最佳混凝剂聚合氯化铝和最佳吸附剂粉末活性炭,其最优投加量分别为60 mg/L和40 mg/L。在此复配条件下,COD去除率由单独投加混凝剂时的62%提高到73%,浊度去除率由88%提高到93%。同时利用分子量分级实验进一步阐述了混凝/吸附复配过程提升污水浓缩效果的机制。在机械加速澄清池连续实验中,在原水COD 300~500 mg/L、浊度130~360 NTU的水质条件下,出水COD稳定在70~86 mg/L之间,去除率达80%以上,出水浊度稳定在10 NTU以下。     

石油污染土壤胶体特征及其稳定性

采集辽河油田石油污染土壤样品并用离心法提取胶体,定性和定量研究了石油污染土壤胶体的主要物理化学性质,通过间歇实验研究了不同p H(p H=4~9)、不同价态阳离子(Na+、Ca2+和Fe3+)和不同价态阴离子(NO-3、SO2-4和PO3-4)存在下的胶体稳定性,比较了阳离子存在下石油污染土壤胶体和未受污染土壤胶体稳定性。研究结果表明,该石油污染土壤胶体总石油烃含量为123.24 mg/g,石油烃主要为直链烷烃和环烷烃。相同p H条件下石油污染土壤胶体Zeta电位负值比未受污染土壤胶体Zeta电位负值高。石油污染土壤胶体稳定性随p H值增加而增加,随着阳离子价数升高而减小,随阴离子价数升高而增大。Ca2+和Cu2+存在下,石油污染土壤胶体比未受污染土壤胶体稳定性更小。Na+和Fe3+存在下,石油污染土壤胶体比未受污染土壤胶体稳定性更大。     

Fluorescence excitation–emission matrix spectra coupled with parallel factor and regional integration analysis to characterize organic matter humification

The present several humification indexes cannot provide the whole fluorescence information on organic matter composition and the evaluation results from them are inconsistent sometimes. In this study, fluorescence excitation–emission matrix spectra coupled with parallel factor analysis and fluorescence regional integration analysis were utilized to investigate organic matter humification, and the projection pursuit cluster (PPC) model was applied to form a suitable index for overcoming the difficulties in multi-index evaluation. The result showed that the ratio between the volume of humic- and fulvic-like fluorescence region and the volume of protein-like fluorescence region not only revealed the heterogeneity of organic matter, but also provided more accurate information on organic matter humification. In addition, the results showed that the PPC model could be used to characterize integrally the humification, and the projected characteristic value calculated from the PPC model could be used as the integrated humification evaluation index.     

Aqueous stabilization of carbon nanotubes: effects of surface oxidization and solution chemistry

Surface oxygen functional groups can affect the morphological characteristics, aggregation kinetics, and adsorption capacity of multi-walled carbon nanotubes (MWCNTs). However, little is known about the quantitative relationship between oxygen content and the dispersion stability of MWCNTs. To investigate the effects of surface oxidization, MWCNTs were oxidized using concentrated H₂SO₄/HNO₃ acids for 0, 1, 2, 4, and 8 h, respectively. Experimental results showed that the oxygen content of MWCNTs increased with surface oxidization time. Linear correlations were found to exist between the oxygen content, critical coagulation concentration (CCC) for NaCl, and critical coagulation pH values of MWCNTs detected by optical density at 800 nm. The CCC values for CaCl₂ increased with oxygen contents for unmodified MWCNTs and lowly oxidized MWCNTs, while which decreased after further increasing the surface oxidization. CCC ratios in the presence of Ca²⁺ to Na⁺ were consistent with the empirical Schulze–Hardy rule for unmodified MWCNTs and lowly oxidized MWCNTs; however, which were much lower than the expected values for highly oxidized MWCNTs. Fulvic acid can clearly increase the stability of MWCNT suspension with unmodified MWCNTs and lowly oxidized MWCNTs, while it cannot affect the dispersion of highly oxidized MWCNTs. This study implied that the oxidation and presence of fulvic acid will possibly increase the mobility, exposure, bioavailability, and toxicity of MWCNTs.