生命周期评价方法及其进展

生命周期评价方法在国外的 发展已近３０年，正成为企业和政府环境管理的工具。国外许多生态标志标准的确定，采用的都是生命周期评价方法，它还是国际标准化组织ＩＳＯ１４００系列标准的重要内容，我国对生命周期评价方法的认识和研究才刚刚开始，该文对生命周平价方法的技术框架，应用和存在的不足等作了简要论述。     

生命周期评价

生命周期评价是一种评价产品、工艺过程或活动从原材料的采集和加工到生产、运输、销售、使用、回收、养护、循环利用和最终处理整个生命周期系统有关的环境负荷的过程.生命周期评价既可以作为评价产品生产全过程的有效手段,又可以作为一种环境管理工具,现已在国际上广泛应用.文章从生命周期评价的概念入手,介绍了生命周期评价产生背景、技术框架、评价方法、应用及其展望.     

第三讲 生命周期设计与管理

在第一讲、第二讲中介绍了产品环境化设计的发展历程和生命周期法及产品系统的概念等内容,在第三讲和第四讲中将继续介绍生命周期设计与管理和生命周期评价的内容。生命周期设计是生命周期概念在产品开发过程设计阶段的应用,生命周期评价则可以用来评价一个产品整个生命周期的环境影响。——编者     

在污泥资源化利用过程中引入生命周期评价方法

生命周期评价是一种评价产品整个寿命周期中环境负荷的方法。为了促进资源的循环利用和经济的可持续发展,在污泥资源化利用过程中引入生命周期评价方法显得非常必要。介绍了引入生命周期评价方法的必要性及污泥资源化利用生命周期评价的内容和步骤。     

生命周期评价在环境保护中的研究与应用

生命周期评价以全新的角度从产品的全过程考察其对环境的影响,是一种科学的新理念和新方法.本文简要介绍了生命周期评价的方法和应用现状,重点论述了LCA在影响评价和环境标志认证标准方面的研究与应用.     

生态标志和产品的生命周期评价

获得生态标志，是对产品环境性能的肯定，表明其整个生命周期的环境性能达到了特定的要求，消费者也可直接根据生态标志图案购得自己喜好的环境友好产品，生命周期评价是一中评价产品，工艺或活动从原料采掘到生产、运输、分销、使用，回用，维护，循环和最终处置的整个生命周期阶段相关环境负荷的过程，大多数生态标志标准的确定都采用了生命周期的评价的方法，文章对生态标志的概念、发展状况、标准的确定性和生命周期评价等作了简     

生命周期方法在天然气基汽车燃料评价中的运用

运用生命周期评价方法,对以天然气为原料生产压缩天然气、甲醇、二甲醚、柴油4种汽车代用燃料系统进行生命周期的能源、环境和经济评价,评价结果是：压缩天然气系统生命周期内的能耗相对少,总成本相对低,对生态环境更友好,压缩天然气是富含天然气地区一段时期内汽车代用燃料的优先选择．     

生命周期评价理论及其在污水处理领域的应用综述

生命周期评价为全面评价污水处理提供了工具。在介绍生命周期评价理论的基础上,对其在污水处理领域的应用理论进行分析,对其国内外应用现状和特点进行回顾性评价。同时展望了生命周期评价在污水处理领域的发展,并提出了意见和建议以推动生命周期评价在我国得到更好的应用。     

生命周期评价

国际标准化组织对生命周期评价(LCA)的定义是:汇总和评价一个产品(或服务)体系在其整个生命周期间的所有投入及产出对环境造成的和潜在的影响的方法。 LCA是一种评价产品、工艺或活动从原材料采集,到产品生产、运输、销售、使用、回用、维护和最终处置整个生命周期阶段有关的环境负荷的过程。它首先辨识和     

层次分析法在生命周期评价中的改进应用研究

层次分析法是一种实用的、多目标决策方法,生命周期评价被看作是21世纪最有潜力的环境管理工具。将层次分析法应用于生命周期评价能够实现生命周期过程多指标的综合评价,但在传统的层次分析法中,仅仅是对一级指标进行简单的叠加,但在实际的应用过程中,不同的指标对综合效益的贡献是不一样的,因此,论文对传统的层次分析法进行了改进,并对某矸石电厂进行评价,充分考虑指标对综合效益的影响,对各指标作赋值处理,使得评价结果更准确。     

Distribution and ecological effect of mercury in Laogang landfill, Shanghai, China

Laogang landfill near Shanghai is the largest landfill in China, and receives about 10000 t of daily garbage per day, Samples of topsoil and plants were analyzed to evaluate mercury pollution from the landfill. For topsoil samples, there were significant correlations among total mercury （HgT）, combinative mercury （Hgc） and gaseous mercury （HgG）, and content of total organic carbon （TOC）, but, no significantly relationship was found between Hg content and filling time. Hg content changes in vertical profiles with time showed that the average Hgv of profiles 1992, 1996, and 2000 was similar, but their average HgG was quite different. HgT was significantly correlated with Hgc in profile 1992 and 2000, and Hgv was significantly correlated with Hg6 in profile 1996. HgG/Hgv ratio in profile samples decreased in the order of （HgG,/HgT）1992〉（HgG/HgT）1996〉〉（HgG/HgT）2000. A simple outline of Hg release in landfill could be drawn： with increasing of filling time, degradation undergoes different biodegradation, accordingly, gaseous mercury goes through small, more, and small proportion to total mercury. Distribution of Hg in plants was inhomogeneous, following the order of leaf〉root〉stem. The highest value of leaf may be associated with higher atmospheric Hg from landfill. Ligneous plants （e.g. Phyllostachys glanca, Prunus salicina and Ligustrum lucidum） are capable of enriching more Hg than herbaceous plants.     

EDTA-enhanced phytoremediation of lead contaminated soil by Bidens maximowicziana

Phytoremediation is a potential cleanup technology for the removal of heavy metals from contaminated soils.Bidens maximowicziana is a new Pb hyperaccumulator,which not only has remarkable tolerance to Pb but also extraordinary accumulation capacity for Pb.The maximum Pb concentration was 1509.3 mg/kg in roots and 2164.7 mg/kg in overground tissues.The Pb distribution order in the B. maximowicziana was:leaf>stem>root.The effect of amendments on phytoremediation was also studied.The mobility of soil Pb and the Pb concentrations in plants were both increased by EDTA application.Compared with CK(control check),EDTA application promoted translocation of Pb to overground parts of the plant.The Pb concentrations in overground parts of plants was increased from 24.23-680.56 mg/kg to 29.07-1905.57 mg/kg.This research demonstrated that B.maximowicziana appeared to be suitable for phytoremediation of Pb contaminated soil,especially,combination with EDTA.     

Decomposition of alachlor by ozonation and its mechanism

Decomposition and corresponding mechanism of alachlor, an endocrine disruptor in water by ozonation were investigated. Results showed that alachlor could not be completely mineralized by ozone alone. Many intermediates and final products were formed during the process, including aromatic compounds, aliphatic carboxylic acids, and inorganic ions. In evoluting these products, some of them with weak polarity were qualitatively identified by GC-MS. The information of inorganic ions suggested that the dechlorination was the first and the fastest step in the ozonation of alachlor.     

Enzymatic oxidation of aqueous pentachlorophenol

The influence of the nonionic surfactant Tween 80 on pentachlorophenol （PCP） oxidation catalyzed by horseradish peroxidase was studied. The surfactant was tested at concentrations below and above its critical micelle concentration （CMC）. Enhancement of PCP removal was observed at sub-CMCs. The presence of Tween 80 in the reaction mixture reduced enzyme inactivation which occurred through a combination of free radical attack and sorption by precipitated products. A simple first-order model was able to simulate time profiles for enzyme inactivation in the presence or absence of Tween 80. At supra-CMCs, the surfactant caused noticeable reductions in PCP removal, presumably through micelle partitioning of PCP which precluded the hydrophobic PCP molecule from interacting with the enzyme.     

基于综合水质标识指数和对应分析法的校园河道水质评价

以三峡大学的校园河道求索溪为研究对象,利用综合水质标识指数法确定求索溪水质类别,分析其水质时空变化规律,并利用对应分析法得出求索溪中不同监测点的主要污染因子.研究结果表明:求索溪整体的综合水质标识指数为7.423,整体水质为劣V类(地表水环境质量标准GB 3838-2002)且黑臭.从时间变化来看,求索溪4月份的水质最差,5月份次之,4、5月份所有监测点的水质都劣于V类且黑臭;8月份水质最好,水质为Ⅳ类;从空间分布来看,8个监测点综合水质标识指数均超过6.0,水质为劣V类,其中6号监测点的水质相对最好,监测点3号的水质相对最差;对应分析法得出求索溪的整体水体污染程度受总氮因子的影响最大,其次为总磷.该研究拟为求索溪及类似校园河道的水环境治理研究提供基础依据和参考.     

Effects of chitosan on growth of an aquatic plant (Hydrilla verticillata) in polluted waters with different chemical oxygen demands

Effects of chitosan on a submersed plant, Hydrilla verticillata, were investigated. Results indicated that H. venicillata could prevent ultrastructure phytotoxicities and oxidativereaction from polluted water with high chemical oxygen demand (COD). Superoxide dismutase (SOD) activity and malondialdehyde (MDA) contents in H. verticillata treated with 0.1% chitosan in wastewater increased with high COD (980 mg/L) and decreased with low COD (63 mg/L), respectively. Ultrastructural analysis showed that the stroma and grana of chloroplast basically remained normal. However, plant cells from the control experiment (untreated with chitosan) were vacuolated and the cell interval increased. The relict of protoplast moved to the center, with cells tending to disjoint. Our findings indicate that wastewater with high COD concentration can cause a substantial damage to submersed plant, nevertheless, chitosan probably could alleviate the membrane lipid peroxidization and ultrastructure phytotoxicities, and protect plant cells from stress of high COD concentration polluted water.     

Removal of cadmium using MnO2 loaded D301 resin

MnO2 loaded weak basic anion exchange resin D301 （Anion exchange resin, macroreticular weak basic styrene） as adsorbent has been prepared and applied to the removal of cadmium. The adsorption characteristics have been investigated with respect to effect of pH, equilibrium isotherms, removal kinetic data, and interference of the coexisting ions. The results indicated that the Cd^2＋ could be efficiently removed using MnO2 loaded D301 resin in the pH range of 3-8 from aqueous solutions with the co-existence of high concentration of alkali and alkaline-earth metals ions. The saturate adsorption capacity of the Cd^2＋ was 77.88 mg/g. The adsorption process followed the pseudo first-order kinetics. The equilibrium data obtained in this study accorded excellently with the Langmuir adsorption isotherm.     

Effect of coagulation pretreatment on the fouling of ultrafiltration membrane

The purpose of this study is to understand the effect and mechanism of preventing membrane fouling, by coagulation pretreatment, in terms of fractional component and molecular weight of natural organic matter （NOM）. A relatively higher molecular weight （MW） of hydrophobic compounds was responsible for a rapid decline in the ultrafiltration flux. Coagulation could effectively remove the hydrophobic organics, resulting in the increase of flux. It was found that a lower MW of neutral hydrophilic compounds, which could remove inadequately by coagulation, was responsible for the slow declining flux. The fluxes in the filtration of coagulated water and supernatant water were compared and the results showed that a lower MW of neutral hydrophilic compounds remained in the supernatant water after coagulation could be rejected by a membrane, resulting in fouling. It was also found that the coagulated flocs could absorb neutral hydrophilic compounds effectively. Therefore, with the coagulated flocs formed on the membrane surface, the flux decline could be improved.     

Penetration analysis of elements and bioleaching treatment of spent refractory for recycling

Acidithiobacillus ferrooxidans ATCC23270 and Acidithiobacillus thiooxidans TM-32 were used for bioleaching of spent refractories of aluminium and copper melting furnaces for their recycling.Firstly,penetration of elements into aluminium melting furnace refractory was investigated and it was found that up to 7 cm from surface was contaminated.Comparison on leaching efficiency by the strains ATCC23270 and TM-32 found that the strain ATCC23270 could treat larger amount of the refractories than the strain TM-32 could do.In the experiment of bioleaching of spent refractory aluminium melting furnace by the strain ATCC23270,high leaching efficiency were obtained on Al,Si,and Ca,and extremely low leaching performance was,however,shown on the rest of elements i.e.,Na,Mn,and Zn.Under the strain TM-32 use,relatively high leaching performance was recognized on Al,Si,Ca,Na,Mn,and Zn.In the experiment of bioleaching for spent refractory copper melting furnace,almost the same leaching trends were shown on Cu,Zn,Al,and Si under the strains ACTT23270 and TM-32 uses.     

Evaluation of phytoextracting cadmium and lead by sunflower, ricinus, alfalfa and mustard in hydroponic culture

Soil contaminated with heavy metals cadmium(Cd)and lead(Pb)is hard to be remediated.Phytoremediation may be a feasible method to remove toxic metals from soil,but there are few suitable plants which can hyperaccumulate metals.In this study,Cd and Pb accumulation by four plants including sunflower(Helianthus annuus L.),mustard(Brassica juncea L.),alfalfa(Medicago sativa L.), ricinus(Ricinus communis L.)in hydroponic cultures was compared.Results showed that these plants could phytocxtract heavy metals, the ability of accumulation differed with species,concentrations and categories of heavy metals.Values of BCF(bioconcentration factor)and TF(translocation factor)indicated that four species had dissimilar abilities of phytoextraction and transportation of heavy metals.Changes on the biomass of plants,pH and Eh at different treatments revealed that these four plants had distinct responses to Cd and Pb in cultures.Measurements should be taken to improve the phytoremediation of sites contaminated with heavy metals,such as pH and Eh regulations,and so forth.