零价铁在废水处理中应用的研究进展

简述了零价铁（ZVI）处理废水的机理。综述了ZVI、纳米零价铁 （nZVI）对焦化废水、军火厂废水、制药废水、橄榄油厂废水、染料废水、含盐类废水及含重金属废水处理的研究进展以及ZVI复合材料处理废水的研究进展。指出将ZVI与超声波、微波及Fenton法等技术联合,形成具有各自优点的新处理技术,将是今后的研究重点。     

膨胀石墨-ZnO复合材料的制备及其光催化降解原油的性能

采用化学氧化-浸渍法制备出膨胀石墨-ZnO（EG—ZnO）复合材料，采用扫描电镜、X射线衍射仪、紫外-可见分光光度法及傅里叶变换红外光谱仪等表征手段对该复合材料的形貌、结构及其光催化降解水面原油的性能进行了研究。研究结果表明，EG—ZnO复合材料保持了膨胀石墨疏松多孔的蠕虫形貌，六方晶系结构的ZnO晶体均匀地分布于膨胀石墨的层间和表面。经紫外光照射72h后，吸附于EG—ZnO复合材料中的原油发生了显著的光催化降解反应。当该复合材料中ZnO的质量分数为80％时，原油的降解率可达35％，降解产物中有酮、醛及醇类等物质。     

稀土偶联剂活化纳米CaCO3改性纸塑复合材料在管材中的应用研究

介绍了以稀土偶联剂对纳米CaCO3进行表面活化处理,并作为改性剂对废旧纸塑复合材料进行生产管材的方案.探讨了纸塑复合材料的配方、纸塑编织袋的处理、工艺及制备方法.结果表明:经稀土偶联剂活化处理的纳米CaCO3进行改性的纸塑复合材料,可改善纸塑复合材料的加工性能,增强物料的界面黏结强度,提高管材的力学性能.     

专利文摘

一种用于光降解全氟有机酸的掺杂二氧化钛炭铁复合材料的制备方法该专利涉及一种用于光降解全氟有机酸的掺杂二氧化钛炭铁复合材料的制备方法。该掺杂二氧化钛炭铁复合材料是将纳米二氧化钛和纳米羟基铁固定在颗粒活性炭上,然后将该材料加入到全氟有     

废旧聚乙烯复合材料的制备与性能研究

介绍了废旧聚乙烯复合材料的制备与性能。以废旧聚乙烯为原材料,通过与超细白炭黑进行纳米复合,制备高性能纳米复合材料;利用木粉、竹粉、稻糠等植物纤维与其进行木塑复合,制备环保型木塑复合材料;重点研究了多单体接枝共聚物在复合材料中的界面改性作用。     

专利文摘

一种吸附与裂化双功能废水处理催化剂的制备方法该发明涉及一种废水处理用吸附与裂化双功能催化剂的制备方法,其特征在于包括以下工艺过程:(1)由多种过渡金属元素作为氧化活性主剂元素,由稀土及钛金属元素作为氧化活性助剂元素;(2)γ-Al_2O_3载体粉末中加入惰性填料和硝酸,经过成型、干燥、煅烧工艺制得成型载体;(3)成型载     

负载型纳米TiO2光催化剂的制备及其光催化活性

采用悬浮聚合法制备粉煤灰-聚苯乙烯微珠载体,通过矿化接枝技术将水热法制备的纳米TiO2负载在粉煤灰-聚苯乙烯微珠载体上,制成负载型纳米TiO2光催化剂。用x射线衍射仪、扫描电子显微镜对负载型纳米TiO2光催化剂进行了表征;通过光催化降解甲醛实验评价了负载型纳米TiO2光催化剂的活性。实验结果表明,纳米TiO2在载体上分散良好,平均粒径为36．4nm;该催化剂活性较高,明显优于粉体纳米TiO2光催化剂,重复使用10次左右,该催化剂的活性无明显下降。     

天然黏土材料附着纳米TiO2对 电解锰渣中锰的吸附固定

采用机械球磨法对膨润土、硅藻土、高岭土3种天然黏土材料进行预处理,通过超声法将纳米TiO_2附着于其上制得复合材料,考察了不同复合材料加入量及养护时间条件下复合材料对电解锰渣中Mn的吸附固定效果。3种天然黏土材料中,硅藻土的平均粒径最小,比表面积和总孔隙度最大,对水中Mn的吸附量也最大。黏土材料附着纳米TiO_2后对电解锰渣中Mn的吸附固定效果较单纯黏土材料有明显改善。在养护时间为12 d、硅藻土附着纳米Ti O_2复合材料加入量为10%(w)的最佳条件下,Mn的TCLP浸出量较原电解锰渣下降了83.04%。     

纳米铁酸盐光催化剂的制备及其在废水处理中的应用综述

概括了纳米铁酸盐(以ZnFe2O4和BiFeO3为代表)光催化剂的制备方法;综述了其在废水处理中的应用现状;讨论了催化反应中铁酸盐的特性及工艺条件(初始反应p H、初始污染物浓度、H2O2的加入等)对有机污染物降解率的影响;介绍了光助-类Fenton氧化反应的机理;对纳米铁酸盐在废水处理应用中存在的问题进行了总结,并对今后的研究方向进行了展望。     

微电解技术在工业废水处理中的应用进展

概述了近年来传统铁碳微电解法在难降解工业废水预处理、污泥处理和重金属去除、低浓度废水处理等领域的研究进展,介绍了通过在铁碳微电解体系中投加其他金属以催化反应的改性微电解法的废水处理效果,以及微电解与电场强化、微波强化、Fenton氧化、生物处理、物化法等其他工艺联合技术在废水处理中的应用现状,探讨了相关微电解技术存在的问题及未来的发展方向。     

Temporal Trends in Mercury Accumulation in Lake Sediments in Sweden

Lake sediment cores were analyzedto study the history of mercury (Hg) pollution andparticularly to determine whether recent sedimentconcentrations have declined in response todeclining atmospheric deposition of Hg. Sedimentcores from 6 forest lakes distributed fromsouthern to northern Sweden and 3 northernmountain lakes were analyzed for Hg using CVAAS. A400 cm sediment profile from Måkevatten insouthwest Sweden indicates that the onset of Hgpollution occurred in the 18th century. Anindisputable increase in Hg concentrationsoccurred concurrent with the appearance ofspheroidal carbonaceous flyash particles (SCP)derived from fossil-fuel combustion, in themid-19th century. There is a strong correlationbetween Hg and SCP concentrations in the sedimentcores (r=0.67 to 0.91), which suggests a strongrelationship between historical Hg pollution andfossil fuel burning. In contrast to sediment corestaken in 1979, maximum Hg concentrations are nowobserved below the sediment surface and declinetowards the sediment surface. This study confirmsthat reductions in atmospheric deposition of Hgover Sweden have resulted in a decreased transferof total Hg to aquatic environments as reflectedby lake sediments, and that lake sediment profilesof Hg concentrations reflect relative trends inthe atmospheric deposition of Hg rather thanpost-depositional diagenetic processes.     

Elemental Concentration in Lichen in Western Anatolia

The deposition patterns of Mn, Fe, Cr, Sb, Zn and As wereinterpreted together with enrichment factor calculations. Samples collected around iron-steel plant had very high concentrations and EF values of Mn, Fe, Cr, Sb and Zn implying that these plants are serious pollution sources in the region. High As concentrations around the settlementareas showed that coal combustion is another important anthropogenic source in the region.     

Volumetric changes in landfill gas flux in response to variations in atmospheric pressure

This paper develops a quantitative model which attempts to relate volumetric changes in landfill gas emissions to variations in the surface atmospheric pressure. The model considers gas emissions as the sum of two terms, one constant over a period of weeks, and the other able to vary on a scale of hours. Results from computer simulations are given which indicate that the magnitude of the variable factor is proportional to the rate at which surface pressure is changing, rather than the actual value of the surface pressure.     

Sulphate and Nitrate in Precipitation and Soil Water in Pine Forests in Latvia

The SO₄–S and NO₃–N concentrations and pH in bulk precipitation, throughfall, stemflow and soil water for the 1994–2004 period were studied in pine forests in Latvia (Rucava and Taurene Integrated Monitoring stations). The SO₄–S and NO₃–N concentrations decreased over the study period, simultaneously with a decrease of acidity in precipitation. The changes were more evident in the western part of Latvia, probably due to declining long-range air pollution from West Europe. The trend of decreasing sulphate concentrations and increasing pH in precipitation were not followed by respective changes in soil water. In the upper soil horizon sulphate ion concentrations and acidity increased in soil water. Over the observation period, nitrate concentrations also showed an increasing trend in soil water at Rucava and Taurene, but these changes were not statistically significant.     

Variations in the Fluoride Level in Precipitation in a Region of Human Impact

The research concerns the Wielkopolski National Park (West Poland), which suffered a huge human impact in the 1970s and 1980s owing to the nearby location of an industrial plant. Since then, fundamental technological changes that it introduced into its production of phosphate fertilizers have radically reduced the amount of pollution emitted. A three-year study (2002–2004) of fluorides in precipitation in open terrain and under tree crowns showed their concentrations to range from levels below the detection limit (0.003 mg/l) to 0.560 mg/l. Those registered under tree crowns were several times higher and indicated substantial dry deposition of fluorides on the trees. The highest values were recorded in 2003, with 43% of samples ranging from 0.01 to 0.05 mg/l, and with 51% of throughfall ranging from 0.10 to 0.50 mg/l. A strong connection was shown to exist between fluoride and sulphate concentrations in the precipitation. An analysis was made of the available data on F concentrations in the air and the dust levels around the factory, but these figures did not show an unequivocal effect on F concentrations in precipitation. A great similarity was found to occur between the fluoride content in rainwater in the Wielkopolski National Park and in the centre of the nearby Poznań metropolitan area, which indicates that there are also other F sources besides the local factory.     

Difficulties in applying extended producer responsibility policies in developing countries: case studies in e-waste recycling in China and Thailand

Developing Asian countries have started to apply the principle of extended producer responsibility (EPR) to electronics and electrical equipment waste (e-waste). This policy approach aims to give electronic appliance manufacturers and importers responsibility for the collection and recycling of discarded electronic equipment. China and Thailand have drafted regulations on the recycling of e-waste with common characteristics such as the financial responsibility of producers and subsidies for collection. Although the proposed system is sensible, taking into account the fact that e-waste is a market-traded commodity, there are two major difficulties in implementing EPR in developing countries. First, it may be difficult for governments to collect funds from producers or importers if smuggled, imitation, or small shop-assembled products have a large share in the market. Second, the system creates incentives for collectors and recyclers to over-report the amount of collected e-waste in order to gain extra subsidies from the fund. Other policy measures such as the enforcement of pollution control regulations on informal recyclers, the prevention of smuggling, and the protection of intellectual property rights should accompany EPR policies.     

Medical wastes characterisation in healthcare institutions in Mauritius

This study was initiated to characterize solid and liquid wastes generated in healthcare institutions and to provide a framework for the safe management of these wastes. The project was carried at three major medical institutions, namely, the Jeetoo Hospital, the Sir Seewoosagur Ramgoolam National (SSRN) Hospital and the Clinic Mauricienne. A waste audit carried out at these sites revealed that approximately 10% of solid wastes was hazardous in nature, consisting mainly of infectious, pathological and chemical wastes. The average amount of hazardous wastes per patient per day was found to be 0.072 kg at Jeetoo hospital, 0.091 kg at SSRN hospital and 0.179 kg at the clinic. The amount of hazardous wastes generated as a function of the number of occupied beds was found to follow a relationship of type y=0.0006x-0.19, where y was the amount of hazardous wastes generated per bed per day and x was the number of occupied beds. The waste quantifying process also revealed that at SSRN Hospital, 0.654 m(3) of water was being consumed per patient per day and the amount of wastewater produced was 500 m(3)/day. Further analysis revealed that the wastewater was polluting with chemical oxygen demand (COD), biological oxygen demand (BOD(5)), total suspended solids (TSS) and coliform content well above permissible limits.     

Future trends in computer waste generation in India

The objective of this paper is to estimate the future projection of computer waste in India and to subsequently analyze their flow at the end of their useful phase. For this purpose, the study utilizes the logistic model-based approach proposed by Yang and Williams to forecast future trends in computer waste. The model estimates future projection of computer penetration rate utilizing their first lifespan distribution and historical sales data. A bounding analysis on the future carrying capacity was simulated using the three parameter logistic curve. The observed obsolete generation quantities from the extrapolated penetration rates are then used to model the disposal phase. The results of the bounding analysis indicate that in the year 2020, around 41–152 million units of computers will become obsolete. The obsolete computer generation quantities are then used to estimate the End-of-Life outflows by utilizing a time-series multiple lifespan model. Even a conservative estimate of the future recycling capacity of PCs will reach upwards of 30 million units during 2025. Apparently, more than 150 million units could be potentially recycled in the upper bound case. However, considering significant future investment in the e-waste recycling sector from all stakeholders in India, we propose a logistic growth in the recycling rate and estimate the requirement of recycling capacity between 60 and 400 million units for the lower and upper bound case during 2025. Finally, we compare the future obsolete PC generation amount of the US and India.     

膜生物反应器中污泥自消化技术进展

介绍了国内外膜生物反应器(MBR)中污泥的消化技术,分析了控制运行条件法、物理法、化学法污泥消化技术及生物法污泥自消化技术的优缺点,指出了在MBR中没置局部厌氧区域法污泥自消化技术的重要意义.     

Material reuse and recycling in construction works in Japan

Journal of Material Cycles and Waste Management - The status of material reuse and recycling in Japan is reviewed with an emphasis on the efforts by the national government. First, the national...