Preparation of activated carbon from coconut shell chars in pilot-scale microwave heating equipment at 60 kW

Experiments to prepare activated carbon by microwave heating indicated that microwave energy can decrease reaction temperature, save the energy and shorten processing time remarkably compared to conventional heating, owing to its internal and volumetric heating effects. The above results were based on the laboratory-scale experiments. It is desirable to develop a pilot-scale microwave heating equipment and investigate the parameters with the aim of technological industrialization. In the present study, the components and features of the self-invented equipment were introduced. The temperature rise curves of the chars were obtained. Iodine numbers of the activated carbons all exceed the state standard of China under the following conditions: 25 kg/h charging rate, 0.42 rev/min turning rate of ceramic tube, flow rate of steam at pressure of 0.01 MPa and 40 kW microwave heating power after 60 kW pre-activation for 30 min. Pore structure of the sample obtained at a time point of 46 h, which contained BET surface area, and pore size distributions of micropores and total pores, was tested by nitrogen adsorption at 77K.     

High levels of natural radioactivity in biota from deep-sea hydrothermal vents: a preliminary communication

Hydrothermal deep-sea vent fauna is naturally exposed to a peculiar environment enriched in potentially toxic species such as sulphides, heavy metals and natural radionuclides. It is now well established that some of the organisms present in such an environment accumulate metals during their lifespan. Though only few radionuclide measurements are available, it seems likely that hydrothermal vent communities are exposed to high natural radiation doses. Various archived biological samples collected on the East Pacific Rise and the Mid-Atlantic Ridge in 1996, 2001 and 2002 were analysed by ICP-MS in order to determine their uranium contents (²³⁸U, ²³⁵U and ²³⁴U). In addition ²¹⁰Po–Pb were determined in 2 samples collected in 2002. Vent organisms are characterized by high U, and Po–Pb levels compared to what is generally encountered in organisms from outside hydrothermal vent ecosystems. Though the number of data is low, the results reveal various trends in relation to the site, the location within the mixing zone and/or the organisms' trophic regime.     

胶团强化超滤中表面活性剂结构差异对苯酚增溶性能的影响研究

在胶团强化超滤(MEUF)技术处理有机物废水中,采用多因素正交实验研究了3种不同类型的阳离子型表面活性剂,即疏水链长度相同,而亲水基头不同;亲水基头相同,而疏水链长度不同的表面活性剂,分析基团差异对于苯酚增溶的影响。结果表明,十六烷基氯化吡啶(CPC)对于苯酚的去除效果最好,其次是十八烷基三甲基溴化铵(OTAB),最后是十六烷基三甲基溴化铵(CTAB)。综合去除效果和经济性两方面考虑,在单因素超滤实验中选择OTAB来重点研究表面活性剂浓度和电解质浓度两个操作参数对于苯酚增溶的影响。     

烧结烟气氨-Fe(Ⅱ)NTA法同时脱硫脱硝

研究了烧结烟气氨-络合法同时脱硫脱硝。实验结果表明,氨-络合法可以实现烧结烟气同时脱硫脱硝,脱硫脱硝效率最高可达99%和40%。最佳运行条件为:Fe(NTA)浓度为0.075 mol/L,p H为5~6,停留时间为1.24 s(350 L/h的烟气流量)及55℃运行温度。     

Determining the Feasibility of Establishing New Multiple-Use Marine Protected Areas in Chile

This paper evaluates the feasibility of establishing a multiple-use marine protected area. The methodology was applied to evaluate three proposed sites in Chile with diverse conservation needs, social stress and poverty levels, and different economic activities (small-scale fishing, heavy industry, and mining activities). We use two broad categories for the evaluation: socio-economic and political–institutional. The methodology uses a combination of secondary data with personal interviews, workshops, and focus groups with stakeholders (e.g., fishermen, unions, politicians, social organizations) from different political, social, and economic backgrounds to characterize current and potential natural and social resources and to evaluate in an ordinal scale the feasibility of establishing the protected area. The methodology allows us to correctly identify the challenges faced in each site and can be used to develop appropriate strategies for balancing economic, social, and environmental objectives. This methodology can be replicated to evaluate the feasibility of other marine or terrestrial protected areas.     

An international comparative study of end-of-life vehicle (ELV) recycling systems

End-of-life vehicles (ELV) have become a global concern as automobiles have become popular worldwide. An international workshop was held to gather data and to discuss 3R policies and ELV recycling systems, their background and present situation, outcomes of related policies and programs, the framework of recycling and waste management, and case studies on related topics in several countries and regions, as well as the essential points of the comparison. Legislative ELV recycling systems are established in the EU, Japan, Korea, and China, while in the US, ELV recycling is managed under existing laws on environmental protection. Since automobile shredding residue (ASR) has a high calorific value and ash content, and includes heavy metals as well as a mass of unclassified fine particles, recycling ASR is considered highly difficult. Countries with a legislative ELV system commonly set a target for recovery rates, with many aiming for more than 95 % recovery. In order to reach this target, higher efficiency in ASR recovery is needed, in addition to material recycling of collectable components and metals. Environmentally friendly design was considered necessary at the planning and manufacturing stages, and the development of recycling systems and techniques in line with these changes are required for sound ELV management.     

扬州市城区内河优化换水方案研究

通过分析扬州市城区内河各河段的流量关系和水质关系,建立城区内河水系优化换水数学模型,合理分配各内河的换水量,使得各内河出水口水质有所改善且相当,实现扬州市城区内河换水方案的优化.开发的开放性可视化优化换水软件,方便用户随时更新河道参数和水质参数,计算不同情况下的换水方案.     

Effects of the parasiticide ivermectin on the cladoceran Daphnia magna and the green alga Pseudokirchneriella subcapitata

Although widely used for the treatment of endo- and ectoparasites in livestock and pets, very few data on chronic effects on aquatic organisms are available for the parasiticide ivermectin. In the present study, toxicity of ivermectin to two freshwater organisms, the cladoceran Daphnia magna and the green alga Pseudokirchneriella subcapitata was investigated. For D. magna, a mean LC(50) 48 h of 5.7 ngl(-1) was derived from 10 acute tests. Chronic toxicity of ivermectin to D. magna was extremely high: with 0.001 and 0.0003 ngl(-1), respectively, nominal LOEC and NOEC based on growth and reproduction were far below the analytical limit of detection for this compound. P. subcapitata was considerably less sensitive to ivermectin than D. magna. For both growth rate and yield, EC(50) was >4,000 microgl(-1), LOEC was 1,250 microgl(-1) and NOEC 391microgl(-1). In view of the high toxicity to D. magna, the use of ivermectin might pose a risk to local aquatic ecosystems. Further studies should be carried out to investigate the effects of ivermectin and its degradation products on pelagic and benthic freshwater invertebrates.     

Integrated bioleaching of copper metal from waste printed circuit board—a comprehensive review of approaches and challenges

Waste electrical and electronic equipment (e-waste) is the most rapidly growing waste stream in the world, and the majority of the residues are openly disposed of in developing countries. Waste printed circuit boards (WPCBs) make up the major portion of e-waste, and their informal recycling can cause environmental pollution and health risks. Furthermore, the conventional disposal and recycling techniques—mechanical treatments used to recover valuable metals, including copper—are not sustainable in the long term. Chemical leaching is rapid and efficient but causes secondary pollution. Bioleaching is a promising approach, eco-friendly and economically feasible, but it is slower process. This review considers the recycling potential of microbes and suggests an integrated bioleaching approach for Cu extraction and recovery from WPCBs. The proposed recycling system should be more effective, efficient and both technically and economically feasible.     

厌氧-水解反应器稳定运行的试验研究

采用造纸废水对厌氧水－水解反应器的启动、运行进行试验研究。结果表明，当ＭＬＶＳＳ在１５ｇ／Ｌ左右，ＣＯＤ容积负荷为１．４５ｋｇ／（ｍ＾３·ｄ），水力负荷为２．０ｍ＾３／（ｍ＾２·ｈ），水国停留时间为４ｈ，污泥颗粒化程度较高，反应器运行效果稳定可靠。