杭州市区备用饮用水源地水质状况及安全分析

于2012—2014年对杭州市区贴沙河、珊瑚沙水库、湘湖、三白潭和喜庵港5个备用饮用水源地进行了109项指标及水质急性毒性监测,并采用加拿大水质指数法进行水质安全评价。结果显示,珊瑚沙水库水质基本符合生活饮用水源地一级保护区Ⅱ类水质标准,其余4个备用饮用水源地水质均不达标;各备用饮用水源地特定项目有少数指标检出但均未超标;湘湖、珊瑚沙水库和贴沙河水质安全已受到影响,三白潭和喜庵港水质安全性差;各备用饮用水源地水质均无急性毒性。     

中国液态生物质燃料产业发展的间接社会收益分析

液态生物质燃料在发展过程中具有外部性,体现出的间接社会收益应得到中国政府的重视,也是该产业扩大发展的重要依据。提出液态生物质燃料产业发展的间接社会收益概念,分析该产业在原料搜集和种植、产品消费等过程中产生的额外经济价值,以度量对改善生态环境的直接作用。在分析生物质燃料原料分布和理清原料搜集的细节后,利用直接市场法测算了未来20年中国发展液态生物质燃料的间接社会收益,发现：到2015年,来自该产业的间接社会收益将达1 000亿元以上,到2030年将突破1万亿元。巨大的社会经济价值从另一个侧面折射出液态生物质燃料产业发展的必要性     

城市污水处理厂工艺方案选择的辅助决策模型

针对目前城市污水处理厂工艺方案选择中存在着较大的主观随意性和不确定性,以及多指标、多层次的特点,将层次分析法与灰色关联分析相结合,提出了工艺方案选择的多层次模糊灰色耦合模型,用于实际方案选择的辅助决策工具。并运用该模型进行了实例研究。     

退田还湖后替代生计的经济评估研究——以洞庭湖西畔山洲垸为例

分析了“湿地保护项目是如何改善民众生计的”这一问题。采用2000～2005年1 474个农户调查问卷作为基本数据,其中964个农户位于洞庭湖西畔山洲垸。得出6个结论：①WWF在西畔山洲垸的替代生计示范项目增加了农户的收入和福利,降低了脆弱性,增强可持续利用的自然资源基础;②妇女、老人以及低收入群体从项目中获益;③参加项目的农户比未参加项目的农户拥有更多的收入和财产;④与2000年项目开始时相比,生计水平有了持续的改善;⑤生计改善的原因是当地社区的积极参与、国家政策机遇、伙伴关系的建立、社区基层组织建设以及适应性管理方法的应用;⑥鱼类和水鸟等返回已恢复的湿地。表明该示范项目达到了自然保护目标。     

替代面法和推算法在淅川库区氨氮干沉降评估中的适用性分析

农业源氨氮沉降是水库型水源地水体收到的重要的外源氮之一,其沉降量评估与来源识别是水体氮污染防控的重要依据 .替代面法和推算法是大气氮素干沉降监测的两种常用方法 .采用替代面法和推算法,于 2019年 9月—2020年 8月对淅川库区周边设置的 5个大气监测点进行干沉降样品采集,测定了样品中氨氮浓度及其氮同位素,探讨了 2 种监测方法在氨氮干沉降通量估算及氨氮来源解析中的适用性 .结果表明：替代面法获得的氨氮干沉降通量为推算法的1.4～2.1倍,2种监测方法获得的氨氮干沉降通量在时空变化趋势上具有一致性;推算法获得的δ¹⁵N-NH₄⁺较替代面法偏负,季均相差为11.1‰,时空差异显著.替代面法在获得淅川库区氨氮干沉降通量方面具有优势,受氨氮分馏影响,直接获得的 δ¹⁵N-NH₄⁺值较初始源 δ¹⁵N-NH₃值存在较大偏差,影响溯源结果的准确性;推算法能够分别获得不同氨氮形态干沉降中的 δ¹⁵N...     

Usability of food industry waste oils as fuel for diesel engines

Two cogeneration units were each fitted with a prechamber (IDI) diesel engine in order to test the feasibility of using waste oils from the food industry as a fuel source, and additionally to test emissions generated by the combustion of these fuels. Esterified waste oils and animal fats as well as mustard oil were tested and compared to the more or less "common" fuels: diesel, rapeseed oil and rapeseed methyl ester. The results show that, in principle, each of these fuels is suitable for use in a prechamber diesel engine. Engine performance can be maintained at a constant level. Without catalytic conversion, the nitrogen oxides emissions were comparable. A significant reduction in NO(x) was achieved through the injection of urea. Combining a urea injection with the SCR catalytic converter reduced NO(x) emissions between 53% and 67%. The carbon monoxide emissions from waste oils are not significantly different from those of "common" fuels and can be reduced the same way as of hydrocarbon emissions, through utilization of a catalytic converter. The rate of carbon monoxide reduction by catalytic conversion was 84-86%. A lower hydrocarbon concentration was associated with fuels of agricultural origin. With the catalytic converter a reduction of 29-42% achieved. Each prechamber diesel engine exhibited its own characteristic exhaust, which was independent of fuel type. The selective catalytic reduction of the exhaust emissions can be realized without restriction using fuels of agricultural origin.     

Determinants of Trust for Public Lands: Fire and Fuels Management on the Bitterroot National Forest

Management of public lands occurs today with high levels of scrutiny and controversy. To succeed, managers seek the support, involvement, and endorsement of the public. This study examines trust as an indicator of managerial success and attempts to identify and measure the components that most influence it. A review of trust literature yielded 14 attributes that were hypothesized to contribute to trust, grouped into the three dimensions of Shared Norms and Values, Willingness to Endorse, and Perceived Efficacy. Operationalizing these attributes and dimensions, a telephone survey was administered to a sample of Montana, USA, residents living adjacent to the Bitterroot National Forest (n = 1,152). Each of the attributes was measured in the context of federal lands fire and fuel management. Structural equation modeling showed that all 14 attributes were found to be influential contributors to levels of trust. Results suggest that if managers are to maintain or increase levels of public trust, they need to consider each of trust’s attributes as they make social, ecological, and economic resource decisions.     

Bioethanol from waste: Life cycle estimation of the greenhouse gas saving potential

This paper considers two alternative feedstocks for bioethanol production, both derived from household waste—Refuse Derived Fuel (RDF) and Biodegradable Municipal Waste (BMW). Life Cycle Assessment (LCA) has been carried out to estimate the GHG emissions from bioethanol using these two feedstocks. An integrated waste management system has been considered, taking into account recycling of materials and production of bioethanol in a combined gasification/bio-catalytic process. For the functional unit defined as the ‘total amount of waste treated in the integrated waste management system’, the best option is to produce bioethanol from RDF—this saves up to 196 kg CO₂ equiv. per tonne of MSW, compared to the current waste management practice in the UK.However, if the functional unit is defined as ‘MJ of fuel equiv.’ and bioethanol is compared with petrol on an equivalent energy basis, the results show that bioethanol from RDF offers no saving of GHG emissions compared to petrol. For example, for a typical biogenic carbon content in RDF of around 60%, the life cycle GHG emissions from bioethanol are 87 g CO₂ equiv./MJ while for petrol they are 85 g CO₂ equiv./MJ. On the other hand, bioethanol from BMW offers a significant GHG saving potential over petrol. For a biogenic carbon content of 95%, the life cycle GHG emissions from bioethanol are 6.1 g CO₂ equiv./MJ which represents a saving of 92.5% compared to petrol. In comparison, bioethanol from UK wheat saves 28% of GHG while that from Brazilian sugar cane – the best performing bioethanol with respect to GHG emissions – saves 70%. If the biogenic carbon of the BMW feedstock exceeds 97%, the bioethanol system becomes a carbon sequester. For instance, if waste paper with the biogenic carbon content of almost 100% and a calorific value of 18 MJ/kg is converted into bioethanol, a saving of 107% compared to petrol could be achieved. Compared to paper recycling, converting waste paper into bioethanol saves 460 kg CO₂ equiv./t waste paper or eight times more than recycling.     

直喷式柴油机燃用脂肪酸甲酯的排放特性

脂肪酸甲酯是由生物脂肪经过酯化反应得到的脂肪酸单酯,具有良好的燃料品质和环境友好性,是生物柴油众多种类中的一种.以纯矿物柴油、脂肪酸甲酯、含30%脂肪酸甲酯与70%柴油的混合燃料和含50%脂肪酸甲酯与50%柴油的混合燃料为燃料,在四缸涡轮增压直喷式柴油机上进行的性能对比实验,表明柴油机燃用脂肪酸甲酯能够保持其动力性和燃料经济性,可以显著降低HC和碳烟排放,但会增加CO和NOx排放.脂肪酸甲酯可以作为柴油机的代用燃料进行推广.     

中国实施规划环评可能出现的问题及其解决方法

目前在我国实施规划环境影响评价存在2种方式,即自我评价和第三方评价.本文分别就其适用对象、介入规划的时机等问题进行了探讨,认为自我评价可以更好地实现 "早期介入"、"多方案比选、优化"等规划环评的重要原则.同时,还对替代方案的概念、作用,规划环评的方法及公众参与在规划环评中的作用等问题进行了初步探讨.