农村生活固体垃圾的处理现状及影响因素

随着我国农村经济与农民收入水平的快速提高,农村生活固体垃圾产生与排放的数量快速增加,已经严重影响了农村环境、农民健康和农业可持续发展.该文的主要目的是基于甘肃和河北省60个村和240个农户的调研资料,深入了解农村生活固体垃圾的处理和管理现状及影响生活固体垃圾有效处理的制约因素.结果表明,大多数村没有处理生活固体垃圾的设施,总体看甘肃省拥有的处理设施要好于河北省.超过一半的村中生活固体垃圾都没有人管理,但部分村开始制定相关的管理计划.描述性统计分析和计量模型的分析结果表明,农村生活固体垃圾的处理状况与农民人均收入水平的提高和交通便利程度的改进有显著正相关关系,而非农就业机会的增加不利于当地生活垃圾的处理.     

完善我国医疗废物集中处置收费政策的思考和建议

医疗废物处置收费政策是医疗废物处置产业化发展的重要前提和保障。当前,医疗废物处置收费政策执行难,欠费、漏费等问题非常突出,医疗废物集中收集十分困难。在对我国医疗废物处置收费政策进行全面分析和评估的基础上,对当前收费政策存在的主要问题和产生的原因进行了分析。以加快完善医疗废物处置收费政策为目标,从完善政策体系、加强监管执法、提高标准合理性、综合确定费用承担方、制定鼓励性的经济政策、提高宣传和缴费意识等方面,提出医疗废物处置收费政策改革完善的若干建议。     

基于星座图法的湖北省农业功能分区

农业功能分区是准确把握县域农业功能定位、推动区域农业功能拓展和向现代农业转型的基础工作。旨在探索运用一种新的分类方法即星座图法在农业功能分区中的应用。剖析现代农业的功能定位问题,从农产品供应、就业与社会保障、生态调节和文化传承与休闲4大类综合功能选取30个定量指标和2个定性指标,构建了湖北省农业功能分区指标体系。采用星座图法,根据星座图中各星点的位置,确定各县（市）单项功能的分等类型;并以此为基础结合分区单元的实际地理位置和社会经济及环境现状,作出湖北省农业功能分区方案。分区结果以县级行政区域为分区单元,按照农业功能分区的基本原则,湖北省分4个农业主导功能区,各主导功能区分为3个二级区共12个二级农业功能区     

有机溶剂中温法溶出光伏组件封装材料乙烯-醋酸乙烯酯

采用有机溶剂邻二氯苯中温法溶出模拟光伏组件的封装材料乙烯-醋酸乙烯酯(EVA),探究了不同条件下EVA的溶出率及模拟组件的分离率,通过正交实验确定了有机溶剂中温法处理EVA的最佳条件.实验结果表明,在反应温度160℃、固液比(光伏组件个数与邻二氯苯体积之比,个/mL)4:100、搅拌转速800 r/min、反应时间24...     

Stabilization of heavy metals in MSWI fly ash using silica fume

The objective of this work was to investigate the feasibility and effectiveness of silica fume on stabilizing heavy metals in municipal solid waste incineration (MSWI) fly ash. In addition to compressive strength measurements, hydrated pastes were characterized by X-ray diffraction (XRD), thermal-analyses (DTA/TG), and MAS NMR (²⁷Al and ²⁹Si) techniques. It was found that silica fume additions could effectively reduce the leaching of toxic heavy metals. At the addition of 20% silica fume, leaching concentrations for Cu, Pb and Zn of the hydrated paste cured for 7 days decreased from 0.32 mg/L to 0.05 mg/L, 40.99 mg/L to 4.40 mg/L, and 6.96 mg/L to 0.21 mg/L compared with the MSWI fly ash. After curing for 135 days, Cd and Pb in the leachates were not detected, while Cu and Zn concentrations decreased to 0.02 mg/L and 0.03 mg/L. The speciation of Pb and Cd by the modified version of the European Community Bureau of Reference (BCR) extractions showed that these metals converted into more stable state in hydrated pastes of MSWI fly ash in the presence of silica fume. Although exchangeable and weak-acid soluble fractions of Cu and Zn increased with hydration time, silica fume addition of 10% can satisfy the requirement of detoxification for heavy metals investigated in terms of the identification standard of hazardous waste of China.     

Experimental evaluation of emission factors of cement kilns burning hazardous wastes

Cement industry is an interesting way to eliminate combustible wastes. Thermal valorization is maximal, conditions of combustion are especially favorable to the destruction and the trapping of pollutants, and there are neither ultimate residues (slag) nor aqueous rejects. Moreover the properties of the cement are not modified. Nevertheless the increased use of substitution fuel may lead to deal with unusual amounts of heavy metals. Tests were realized on several rotary cement kilns with varying substitution ratios of fossil fuels by wastes. Mass balances were fitted over the whole plant, and emission factors were explained.     

A comparative assessment of waste incinerators in the UK

The uptake in Europe of Energy from Waste (EfW) incinerator plants has increased rapidly in recent years. In the UK, 25 municipal waste incinerators with energy recovery are now in operation; however, their waste supply chains and business practices vary significantly. With over a hundred more plant developments being considered it is important to establish best business practices for ensuring efficient environmental and operational performance. By reviewing the 25 plants we identify four suitable case study plants to compare technologies (moving grate, fluidised bed and rotary kiln), plant economics and operations. Using data collected from annual reports and through interviews and site visits we provide recommendations for improving the supply chain for waste incinerators and highlight the current issues and challenges faced by the industry. We find that plants using moving grate have a high availability of 87–92%. However, compared to the fluidised bed and rotary kiln, quantities of bottom ash and emissions of hydrogen chloride and carbon monoxide are high. The uptake of integrated recycling practices, combined heat and power, and post incineration non-ferrous metal collections needs to be increased among EfW incinerators in the UK. We conclude that one of the major difficulties encountered by waste facilities is the appropriate selection of technology, capacity, site, waste suppliers and heat consumers. This study will be of particular value to EfW plant developers, government authorities and researchers working within the sector of waste management.     

Biodiversity Conservation, Ecosystem Functioning, and Economic Incentives under Cocoa Agroforestry Intensification

Abstract:  World chocolate demand is expected to more than double by 2050. Decisions about how to meet this challenge will have profound effects on tropical rainforests and wild species in cocoa-producing countries. Cocoa, "the chocolate tree," is traditionally produced under a diverse and dense canopy of shade trees that provide habitat for a high diversity of organisms. The current trend to reduce or eliminate shade cover raises concerns about the potential loss of biodiversity. Nevertheless, few studies have assessed the ecological consequences and economic trade-offs under different management options in cocoa plantations. Here we describe the relationships between ant ecology (species richness, community composition, and abundance) and vegetation structure, ecosystem functions, and economic profitability under different land-use management systems in 17 traditional cocoa forest gardens in southern Cameroon. We calculated an index of profitability, based on the net annual income per hectare. We found significant differences associated with the different land-use management systems for species richness and abundance of ants and species richness and density of trees. Ant species richness was significantly higher in floristically and structurally diverse, low-intensity, old cocoa systems than in intensive young systems. Ant species richness was significantly related to tree species richness and density. We found no clear relationship between profitability and biodiversity. Nevertheless, we suggest that improving the income and livelihood of smallholder cocoa farmers will require economic incentives to discourage further intensification and ecologically detrimental loss of shade cover. Certification programs for shade-grown cocoa may provide socioeconomic incentives to slow intensification.     

Theoretical and Empirical Analysis on Influence Factors of Modern Agricultural Equipment Level in the Processof Agricultural Sustainable Development

To promote modern agricultural equipment level is one characteristic of constructing and developing modern agriculture in China.This paper makes up stepwise linear regression analysis model of influence factors of modern agricultural equipment level,and chooses rural labor,per capita income of rural residents,rural investment,proportion of people at secondary education level and at higher level in per hundred rural labor force and arable land area as independent variables,and total power of machine as induced variable.The major results show that the relativity of modern agricultural equipment level,rural investment and education level of peasants is remarkable,and they are the major influence factors of modern agricultural equipment level.Raising investment level of rural infrastructure construction as well as and research and development and promotion of advanced and applicable modern agricultural equipment,improving quality and education level of peasants can accelerate the development of China’s modern agricultural equipment effectively in the process of agricultural sustainable development.     

立式加热炉节能减排可行性研究

大庆油田原稳装置采用立式加热炉,烟气中存在大量的废热。在现有装置运行中,烟气直接排放,浪费了大量的热量。通过在实验装置中可回收废热资源及废热回收技术研究,采用热管技术回收烟气废热,用于预热空气,不仅会节能降耗,给企业创造可观的经济效益,还会减少大气污染,创造良好的社会效益。