硅基纳米凝胶固化重金属的实验研究

本文利用硅基纳米凝胶与冶炼渣,研制了一种硅基纳米稀土凝胶固化物来固化/稳定重金属,采用浸出实验研究了硅基纳米凝胶技术对重金属的固化/稳定效果,并进一步探讨了重金属的迁移机制和长期安全性。研究表明：碳酸锂渣经过硅基纳米稀土凝胶技术固化形成硅基纳米稀土凝胶固化物后,经硫酸硝酸法浸出实验,重金属浸出浓度远低于规定的上限值,锁定率均在93.5%以上,而且各种耐久性能远超普通混凝土,安全性优良。因此,硅基纳米凝胶可以成为固化/稳定化有害元素的可靠材料。     

Fe-P双掺杂二氧化钛复合材料的制备及其对铊的吸附研究

以钛酸四丁酯为原料,利用水解法构造了Ti-O-Ti的空间结构,通过添加有机硝酸铁和磷酸氢二铵两种原料,向其空腔内引入Fe、P双元素掺杂,得到P-FeN-TiO₂复合材料。使用扫描电镜(SEM)观察了材料的表面形貌,通过吸附等温线、吸附动力学拟合模型分析材料对铊的吸附性能;考察不同溶液pH值、阳离子共存时对铊吸附进程的影响。结果表明：P-Fe-TiO₂复合材料具有多孔结构,吸附符合单分子层吸附,Langmuir拟合最大吸附容量283.1 mg/g,吸附大约2 h达到平衡,强酸性环境会抑制铊的吸附,随着p H值的升高吸附容量逐渐增大,K(Ⅰ),Na(Ⅰ)离子的存在对吸附干扰较小,Ca(Ⅱ)离子的存在会与Tl(Ⅰ)竞争有效的吸附结合位点,导致吸附效率降低,根据吸附前后材料的XPS表征分析,P-FeN-TiO₂复合材料对Tl(Ⅰ)的吸附机理为Ti-OH、P=O、Fe-OH三种基团与Tl(Ⅰ)发生了络合作用,从而实现铊的去除。     

三维载铁石墨烯对四环素和环丙沙星类抗生素的吸附性能与机理

制备了三维载铁石墨烯材料(3D-rGO-Fe3O4),研究其吸附四环素(TC)、环丙沙星(CIP)等污染物的吸附性能与机理.实验结果表明,3D-rGO-Fe3O4对于TC和CIP均具有较好的吸附效果,与单一污染物相比,复合污染中两者的吸附量均有所降低.3D-rGO-Fe3O4对TC和CIP的吸附过程更符合准二级动力学吸...     

RD吸附氧化法处理富营养化水源水的中试研究

采用RD吸附氧化法处理富营养化水源水的中试研究表明,该法可有效去除原水中的氨氮及COD,去除率可分别达到并保持在99％和75％,且运行费用远低于活性炭吸附法,是一种经济、有效的处理富营养化水源水的方法。     

分子模拟技术用于ZSM-5吸附丙酮气体的机理研究

丙酮作为一种典型的挥发性有机物,易给环境空气带来不利的影响。文章以ZSM-5分子筛吸附材料作为吸附剂,丙酮分子作为吸附质,选用分子模拟技术,构建了铝原子分数分别为1 at%,2 at%,3 at%,4 at%不同类型的ZSM-5分子筛分子结构模型,从分子层面阐释ZSM-5分子筛与丙酮之间的吸附机理。通过对吸附等温线、吸附热、孔隙率、径向分布函数、扩散系数等研究,结果分析表明,1 at%Si/Al原子比改性的ZSM-5分子筛吸附效果优于其他Si/Al原子比改性的ZSM-5分子筛。     

负载型纳米TiO2光催化剂的制备及其降解水中微量间二甲苯的研究

采用浸涂-烧结法制备的纳米TiO2光催化剂负载量约为6mg／g载体，催化剂经5次重复使用其催化效果稳定，表明催化剂表面TiO2粉体负载牢固；以高压汞灯为光源，对水中微量间二甲苯的负载型纳米TiO2光催化氧化过程的研究表明：初始浓度在6．68～17．36mg／L的范围内，间二甲苯的光催化反应遵循表现一级反应动力学规律，反应的表现速率常数随溶液初始浓度的增大而减小，半衰期则随初始浓度的增大而增加。     

壳聚糖改性膨润土对邻苯二甲酸二乙酯的吸附研究

以膨润土为载体,壳聚糖为改性剂,制备了壳聚糖-膨润土复合吸附剂,研究了其吸附效果。实验结果表明:pH值为4~6.8,复合吸附剂用量为2.5 g,温度为25℃,吸附时间为10 min,初始浓度为20 mg/L的邻苯二甲酸二乙酯(DEP)废水去除率可达到59%。相对于原土,改性膨润土吸附效果有明显提高。     

改性少根根霉对钍(IV)的吸附研究

本文研究改性少根根霉对钍（Ⅳ）的吸附。在30℃,起始pH=4．0时,未改性少根根霉对钍的饱和吸附容量可达198．7mg／g干菌。用NaOH改性处理后少根根霉的吸附能力有较大提高,在30℃,吸附反应的最佳pH范围在4～4．5时,其饱和吸附量为265mg／g干菌。     

改性椰壳活性炭对工业废水中氨氮的吸附行为研究

为高效去除工业废水中的氨氮化合物,采用椰壳活性炭为原材料,通过碱性溶液改性制备高性能吸附剂。通过表面特征分析发现2 mol/L氢氧化钠改性后的椰壳活性炭孔体积和吸附平均孔径最小,比表面积最大;分析不同体系温度对改性活性炭吸附性能的影响,结果表明：温度对于氨氮的吸附效率影响较大,在35℃时的吸附效果最优,利用等温吸附模型Langmuir方程拟合得到计算理论吸附量为38.8 mg/g;改性椰壳活性炭的吸附行为符合准二级动力学模型,进一步表明椰壳活性炭对废水中氨氮化合物的吸附是易于发生的化学吸附过程。由此可见,改性椰壳活性炭作为一种高性能吸附材料,在去除水中的氨氮化合物方面具有良好的应用价值。     

活性污泥吸附重金属Cr6+的研究

以活性污泥为材料,采用不同时间、温度、pH进行吸附重金属Cr^6 的研究。实验结果表明,当吸附时间为15min,吸附温度为28℃,吸附pH=7时具有较好吸附效果。在此条件下,当重金属Cr^6 浓度为50mg/L,其吸附率可达97．2％。     

Application of surface molecular imprinting adsorbent in expanded bed for the adsorption of Ni(2+) and adsorption model

A new surface molecular imprinting adsorbent (SMIA) was used in an expanded bed. The expansion ratio and adsorption performance were studied at different volumetric rates, inlet concentrations, and pH values. A model based on the Adams-Bohart adsorption model of breakthrough curves was established. The predicted curves had good agreement with the experimental curves. The breakthrough time (T(1/2)) decreased with increasing inlet concentration when the outlet concentration was half the initial concentration (C/C(0)=0.5). The inlet concentration had little effect on the adsorption rate constant (k(1)) value when the initial concentration (C(0)) was above 150 mg/L. However, T(1/2) values increased with increasing initial pH of the inlet solution, and the k(1) value decreased due to the competition between H(+) and Ni(2+).     

Ground-level ozone in the Pearl River Delta and the roles of VOC and NO(x) in its production

In many regions of China, very rapid economic growth has been accompanied by air pollution caused by vehicle emissions. In one of these regions, the Pearl River Delta, the variations of ground-level ozone and its precursors were investigated. Overall, the ambient concentrations of NO(2) increased quickly between 1995 and 1996, but then slightly decreased due to stringent nitrogen oxide (NO(x)) emission controls. Nonetheless, ambient NO(2) levels in the Pearl River Delta remained high. The regional average concentrations of volatile organic compounds (VOCs) were 290 ppbC in summer and 190 ppbC in autumn. Local emissions and long-distance transportation of pollutants play important roles in the regional distribution of VOCs. Ambient O(3) production is significant in urban areas and also downwind of cities. The relative incremental reactivities (RIRs), determined by an observation-based model, showed that ground-level ozone formation in the Guangzhou urban area is generally limited by the concentrations of VOCs, but there are also measurable impacts of NO(x).     

Adsorption of Pb and Cd on the natural surface coatings (NSCs) in the presence of organochlorine pesticides: a preliminary investigation

Adsorption of Pb and Cd in the presence and absence of organochlorine pesticides (OCPs) on natural surface coatings (NSCs), which were collected in the Nanhu Lake in Changchun, China, was measured in order to investigate the effect of the OCPs on the adsorption of heavy metals on the NSCs. Adsorption of Pb/Cd was carried out under controlled laboratory conditions (mineral salt solution with defined species, ionic strength 0.05 mol/l, 25 degrees C and pH 6.0) with initial Pb and Cd concentrations ranging from 0.2 to 2.5 mol/l. The classical Langmuir adsorption isotherm was applied to estimate the equilibrium coefficients of the adsorption of Pb and Cd on the NSCs. Adsorption interference between Pb/Cd and the OCPs on the NSCs indicated that the adsorption of Pb/Cd on the NSCs was influenced by the OCPs, and competitive adsorption between Pb and the OCPs was observed while adsorption of Cd was enhanced by addition of the OCPs. Adsorption data fit the Langmuir isotherm well for the NSCs treated with the OCPs at different equilibrium concentrations. The results showed that the amount of adsorbed Pb decreased by more than 40% while the amount of adsorbed Cd increased by over 60% with an increase in the initial concentrations of the OCPs ranging from 0 to 5.0 microg/l and that adsorption of Pb/Cd on the NSCs was strongly affected by the OCPs. This preliminary study highlights the importance of the OCPs on the NSCs in controlling the transport, fate, biogeochemistry, bioavailability and toxicity of trace metals in aquatic environments.     

A Framework for Designing Ecological Monitoring Programs for Protected Areas: A Case Study of the Galachos del Ebro Nature Reserve (Spain)

The assessment of management effectiveness in protected areas, i.e., the evaluation of whether management strategies are actually helping to achieve stated goals, is becoming a priority. In any such evaluation, accurate information concerning the dynamics of the managed system is required—information that is gathered through monitoring. Few protected areas, however, have well-developed monitoring plans, and reserve managers are faced with a shortage of protocols for their design. This paper proposes a methodology, applicable to a wide range of situations, for designing such plans. The process begins with the precise definition of the aims of the monitoring plan, followed by the identification of key ecological processes and management objectives for the area, and finally the selection of a reduced set of indicators. These indicators are represented at three levels of growing complexity, allowing the plan to be followed in a modular fashion and in agreement with available resources.     

岷江干流（成都段）水体污染防治对策研究

本文通过对岷江干流（成都段）地表水和地下水的综合研究，分别提出了地表水污染防治对策和地下水水质防护措施，划分出了地表水防治不同时期的目标以及地下水开采管理目标。     

规划环境影响评价(PEIA)技术框架与指标体系构建初探

对实施规划环境影响评价的原则进行了分析;重点探讨了实施规划环境影响评价的技术框架和规划环境影响评价指标体系的构建,指出在形成规划方案时,是规划环境影响评价介入的最佳时间,提出建立规划环境影响评价指标体系的两种模式--＂生态-环境-资源与能源利用-社会-经济＂模式和基于DPSIR框架的指标模式,讨论了运用层次分析法（AHP）确定指标权重的过程.     

Ethics in the Societal Debate on Genetically Modified Organisms: A (Re)Quest for Sense and Sensibility

Via a historical reconstruction, this paper primarily demonstrates how the societal debate on genetically modified organisms (GMOs) gradually extended in terms of actors involved and concerns reflected. It is argued that the implementation of recombinant DNA technology out of the laboratory and into civil society entailed a “complex of concerns.” In this complex, distinctions between environmental, agricultural, socio-economic, and ethical issues proved to be blurred. This fueled the confusion between the wider debate on genetic modification and the risk assessment of transgenic crops in the European Union. In this paper, the lasting skeptical and/or ambivalent attitude of Europeans towards agro-food biotechnology is interpreted as signaling an ongoing social request – and even a quest – for an evaluation of biotechnology with Sense and Sensibility. In this (re)quest, a broader-than-scientific dimension is sought for that allows addressing the GMO debate in a more “sensible” way, whilst making “sense” of the different stances taken in it. Here, the restyling of the European regulatory frame on transgenic agro-food products and of science communication models are discussed and taken to be indicative of the (re)quest to move from a merely scientific evaluation and risk-based policy towards a socially more robust evaluation that takes the “non-scientific” concerns at stake in the GMO debate seriously.     

A comparative study for the sorption of Cd(II) by K-feldspar and sepiolite as soil components, and the recovery of Cd(II) using rhamnolipid biosurfactant

This study investigated the sorption characteristics and recovery of selected heavy metal Cd(II) from K-feldspar and sepiolite, representative soil components, using rhamnolipid biosurfactant. Although the proposed technique was classified as a soil bioremediation process, it can also be applied to treatment of waste waters containing Cd(II) ions with minor modifications. The effect of initial Cd(II) concentration on sorption capacity was characterized by determining the sorption isotherms. Of the four models examined, the Freundlich model showed the best fit for the sorption of Cd(II) on K-feldspar, whereas the Langmuir-model was used successfully to characterize the sorption of Cd(II) on sepiolite. Although a high Cd(II) uptake of 7.49 mmol/kg by K-feldspar was obtained, sepiolite was a superior Cd(II) accumulater, with a maximum Cd(II) uptake of 24.66 mmol Cd(II)/kg. The presence of Cd(II) in the sepiolite or K-feldspar prior to addition of the rhamnolipid generally resulted in less rhamnolipid sorption to sepiolite or K-feldspar. The maximum Cd(II) desorption efficiency by rhamnolipid from K-feldspar was substantially higher than that of sepiolite and determined to be 96% of the sorbed Cd(II), whereas only 10.1% of the sorbed Cd(II) from sepiolite was recovered by rhamnolipid solution.     

Green research and development (R&D) investment and its impact on the market value of firms: evidence from South African mining firms

The importance of global corporate green research and development (R&D) investment is gaining momentum and South Africa is no exception. This paper examines growing economic perceptions that green financial and stock-market systems result in heightened corporate hyperopia and therefore increase long-term and future green investment associated with R&D. It reports on the findings of a survey of 14 South African mining firms listed on the Johannesburg Stock Exchange SRI index. The study found, that, these firms’ market value showed a positive association with Green R&D. It also revealed increased Green R&D activity among large mining firms in the country and that they are highly likely to maintain their level of such investment in the coming years. The study's outcomes thus add to the body of empirical knowledge on firm hyperopia in relation to corporate greening initiatives.