Environmental assessment of garden waste management in the Municipality of Aarhus, Denmark

An environmental assessment of six scenarios for handling of garden waste in the Municipality of Aarhus (Denmark) was performed from a life cycle perspective by means of the LCA-model EASEWASTE. In the first (baseline) scenario, the current garden waste management system based on windrow composting was assessed, while in the other five scenarios alternative solutions including incineration and home composting of fractions of the garden waste were evaluated. The environmental profile (normalised to Person Equivalent, PE) of the current garden waste management in Aarhus is in the order of −6 to 8 mPE Mg⁻¹ ww for the non-toxic categories and up to 100 mPE Mg⁻¹ ww for the toxic categories. The potential impacts on non-toxic categories are much smaller than what is found for other fractions of municipal solid waste. Incineration (up to 35% of the garden waste) and home composting (up to 18% of the garden waste) seem from an environmental point of view suitable for diverting waste away from the composting facility in order to increase its capacity. In particular the incineration of woody parts of the garden waste improved the environmental profile of the garden waste management significantly.     

火电厂CO2捕集与封存技术探讨

火电厂CO2减排技术主要包括燃烧前处理、燃烧中减排及燃烧后捕集三类。介绍了IGCC、富氧燃烧、胺吸收法、生物法等CO2捕集与封存技术,分析其存在问题及应用前景。     

燃煤电厂袋式除尘器滤料耐氧化性能试验研究

燃煤电厂锅炉烟气中含有SOx和NOx,会氧化腐蚀滤料。试验研究了燃煤电厂布袋除尘器滤料断裂强力与运行时间的关系。结果表明,滤料在酸性环境中会被氧化同时断裂强力下降,但断裂强力下降后均会出现反弹,后处理工艺可提高滤料的抗氧化性能,但会降低滤料的断裂强力。     

Exposure assessment of operators to pesticides in Kongou,a sub-watershed of Niger River valley

The use of pesticides in horticultural sector in Niger has become an integral part of modern agriculture. Nevertheless, their inappropriate use can generate negative health effects to operators. A study was carried out among Kongou farmers in order to assess their potential dermal exposure (PDE). The UK-POEM model was used to quantify the PDE during mixing/loading and application according to the local practices. In order to determine which parts of the operator body are subject to most contamination during spraying and to validate the theoretical model used, a patch method was used with a tartrazine dye. The deposits of the tartrazine on patches were measured by colorimetry thanks to the absorbance value determined after their extraction in water and a calibration curve. A total of ten spraying trials (five trials with the hand-held sprayer and five others with the backpack sprayer) were performed by different producers at 0.5 and 1 m height for each trial. The survey shows that 92% of the farmers are illiterate and the most common active substances identified are organophosphate or pyrethroids insecticides. Seventy percent of operators do not use any personal protective equipment (PPE) during mixing/loading or spraying. The predictive systemic exposure levels vary from 0.0027?mg kg^?1 bw per day to 0.7692?mg kg^?1 bw per day for backpack sprayer and from 0.0261?mg kg^?1 bw per day to 0.9788?mg kg^?1 bw per day for hand-held sprayer, several times higher the Acceptable Operator Exposure Level (AOEL) for some actives substances. Theoretical modeling indicates more exposure of operator by a hand-held sprayer than a backpack sprayer. The patch method results show that the deposits of dye increase when the position of sprayer nozzle increases from 0.5 to 1 m for the two sprayers. All parts of the operator body are contaminated but lower body parts and chest are the most exposed. The patch method results also show that hand spraying contaminates operator more than backpack spraying, confirming the results of the theoretical model.     

半干法脱除球团烟气中的SO2及Hg0

采用钙基吸收剂及复合氧化剂半干法脱除模拟球团烟气中的SO_2及Hg~0,考察了多因素条件对吸收效果的影响。实验结果表明,在以NaClO和NaClO_2为复合氧化剂、 NaClO与NaClO_2体积比1∶0.5、复合氧化剂质量分数3%、反应温度110℃、钙基吸收剂质量3.0 g、模拟烟气进气流量1.2 L/min的条件下,SO_2和Hg~0的脱除率分别为98%和93%,证明钙基吸收剂与复合氧化剂对污染物球团烟气中的SO_2和Hg~0有良好的脱除作用。     

锐钛矿-金红石混合晶型TiO2降解气相苯

用溶胶-凝胶法并通过控制煅烧温度合成不同晶相比的混合晶型纳米TiO_2,在紫外光光照下降解气相苯。考察了苯初始质量浓度、紫外灯光照强度和催化剂加入量对苯去除率的影响;探究了光催化降解气相苯的动力学特征。结果表明:450℃煅烧制备的催化剂降解苯效率最高,此催化剂金红石相质量分数为6.30%;在苯初始质量浓度为74.39 mg/m~3、催化剂加入量为7 g、光照强度为2.18 klux的最佳条件下反应84 min,苯去除率达99.73%;光催化降解率与光照强度之间符合0.5级动力学特征;当催化剂加入量为3 g时,单位时间单位质量催化剂降解苯的质量最多;苯的光催化降解反应均符合一级动力学方程。     

Ti3C2纳米层状材料对废水中Cr（Ⅵ）的光催化去除性能

以Ti₃AlC₂为原料,采用HF刻蚀工艺制备出12种Ti₃C₂纳米层状材料,对其形貌进行了表征,并考察了以其作为光催化剂对废水中Cr（Ⅵ）的处理效果。实验结果表明：HF体积分数为80%、刻蚀时间为48 h时得到的MX-80-48的形貌较好;MX-80-48具有类似石墨烯的二维层状结构,纳米层厚度约20~50 nm,孔径2~10 nm,比表面积14.8 m²/g,在400~700 nm可见光范围内表现出强烈的吸光性;当Cr（Ⅵ）的初始质量浓度为40.00 mg/L、MX-80-48投加量为200 mg/L、pH=2、反应时间4 h（暗反应1 h+光照3 h）时,Cr（Ⅵ）去除率可达100%。     

水环境中石油类物质分析方法探讨

在详述了国内外石油类分析方法的基础上,对各方法的适用范围、优缺点及可比性进行了深入分析,阐述了各类方法存在的共性问题,指出按照石油类物质毒性大小分别定量分析的方法将是未来的发展趋势。     

Production and characterization of biodiesel from Eriobotrya Japonica seed oil: an optimization study

Biodiesel is now-a-days recognized as a real potential alternative to petroleum-derived diesel fuel due to its number of desirable characteristics. However, its higher production cost resulting mainly due to use of costly food-grade vegetable oils as raw materials is the major barrier to its economic viability. Present work is an attempt to explore the potential of Eriobotrya japonica seed oil for the synthesis of biodiesel using alkali-catalyzed transesterification. Optimization of production parameters, namely molar ratio of alcohol to oil, amount of catalyst, reaction time and temperature, was carried out using Taguchi method. Fatty acid composition of both oil and biodiesel was determined using GC and H¹ NMR. Alcohol to oil molar ratio of 6:1, catalyst amount of 1% wt/wt, 2 h reaction time and 50 ^°C reaction temperature were found to be the optimum conditions for obtaining 94.52% biodiesel. Highest % contribution was shown by the ‘amount of catalyst’ (67.32%) followed by molar ratio of alcohol to oil (25.51%). Major fuel properties of E. japonica methyl esters produced under optimum conditions were found within the specified limits of ASTM D6751 for biodiesel, hence it may be considered a prospective substitute of petro-diesel.     

金属冶炼进口物料的固体废物鉴别方法

建立了金属冶炼进口物料的固体废物鉴别方法,并利用该方法对海关查扣的3种金属冶炼进口物料进行了固体废物鉴别。鉴别结果显示:物料1、2和3的自然属性分别为砷含量超标铜精矿、锰阳极泥、回转窑氧化锌,产生来源分别为有害物质超标的产品、污染控制设施产生的物质、有意识加工的目标产物;物料1和2属于我国禁止进口的固体废物,物料3不属于固体废物。本文建立的固体废物鉴别方法可行,可为金属冶炼进口物料的固体废物鉴别和监管提供参考。