我国燃烧电厂二氧化硫排放现状及减排技术措施

本文分析了我国燃煤电厂二氧化硫排放现状，指出燃煤电厂减排SO2管理措施不到位，经济政策不落实，国产化脱硫技术尚不成熟是目前我国燃煤电厂二氧化硫排放存在的主要问题。提出燃用低硫煤或洗选煤，采用煤炭清洁燃烧技术，建设烟气脱硫装置是解决我国燃煤电厂二氧化硫排放的有效措施。     

全省燃煤电厂脱硫设施运行调度会召开

近日，省环保厅在邢台市兴泰发电有限公司组织召开全省燃煤电厂脱硫设施运行调度会。会议分析了当前污染减排形势，剖析了燃煤电厂脱硫设施运行中存在的问题，对下一步燃煤电厂二氧化硫减排工作进行了部署。省环保厅厅长姬振海做了重要讲话，副厅长杨智明主持会议并通报了上半年全省燃煤电厂脱硫设施运行中存在的问题。     

燃煤电厂脱硫工艺及工艺选择要素分析

目前,人们的环保意识逐渐提升,而燃煤电厂排放的二氧化硫严重污染着环境,同时对人们的身体健康也有着一定的危害,因此,燃煤电厂脱硫工艺的研究是必要的,有着重要的作用。燃煤电厂脱硫工艺的选择要对其经济因素、环境因素与技术因素等进行综合的研究与分析,从而保证其工艺的经济性与环保性。本文将分析燃煤电厂脱硫技术及其原理,同时介绍燃煤电厂烟气脱硫的工艺选择,旨在减少燃煤电厂二氧化硫的排放,实现对环境的保护。     

云南省火电厂二氧化硫排放现状及控制对策

经济增长带来的能源消耗使得火电厂排放了越来越多的二氧化硫,国家对环保的重视出台了更为严格的大气污染物排放标准GB13223—2011,为了更好的控制大气污染、改善大气质量,对云南省火电厂二氧化硫排放进行了调查和研究,概述了云南省火电厂脱硫装置运行情况和二氧化硫排放现状,分析了达到GB 13223—2011规定排放限值需满足的脱硫效率,并简要总结了云南省火电厂脱硫系统存在的问题及改进措施,最后对不满足要求的脱硫系统提出了改造对策和建议。     

中国脱硫设备亟待升级

随着工业化进程的加快，二氧化硫污染日渐严重，烟气脱硫已经成为电厂与工矿企业控制二氧化硫排放的主要措施。由于煤炭在我国一次能源中的重要地位，大面积推广脱硫设备成为必需，这也关系到“十一五”期间二氧化硫减排目标的实现。 最近几年，越来越多的企业开始上马脱硫项目，在脱硫技术大多依靠国外进口的今天，我国的脱硫设备能否满足市场需要，成为人们关注的焦点。     

燃煤电厂烟气脱硫设施出口二氧化硫排放量统计方法比较

本文比较了监测数据法、物料衡算法和在线数据法统计燃煤电厂烟气脱硫设施出口二氧化硫排放量的方法,并对比分析了三种方法的实际监测结果和优缺点,指出在线监测法能够准确反映电厂排污情况,对监测、考核燃煤电厂烟气脱硫设施运行和二氧化硫排放量具有现实意义。     

粤港力推跨区域排污权交易

8月初，国家环保总局污染控制司副司长李新民透露，为实现“十一五”期间的二氧化硫控制目标，环保总局拿出的措施是：严格按照排放绩效核定电厂的二氧化硫排放总量；强化现有和新建电厂的脱硫设施建设；运用排污权交易、排污权有偿获得来促进二氧化硫的减排。     

现有燃煤电厂二氧化硫治理“十一五”规划研究

结合《现有燃煤电厂二氧化硫治理“十一五”规划》的编制背景,根据《国民经济和社会发展第十一个五年规划纲要》及相关法规、政策、标准等,重点分析了达标排放率、排放总量、排放绩效、脱硫机组容量等主要目标的选择及目标值的确定方法,并对“十一五”末全国电力二氧化硫排放量以及脱硫机组容量进行了预测.预计到2010年,全国电力二氧化硫排放总量将达到862×104 t,比2005年减少33.7%;全国烟气脱硫机组投运及在建容量将达到3.8×108 kW,占“十一五”末煤电装机总量的64.0%;全国燃煤电厂二氧化硫排放绩效指标由2005年的6.4 g/(kW·h)下降到2.7 g/(kW·h).同时进行了“十一五”现有燃煤电厂二氧化硫治理的投资分析与风险分析.提出通过完善二氧化硫总量控制制度,强化政策引导,加快脱硫产业化发展,充分发挥政府、行业组织和企业的作用确保目标的实现.      

燃煤电厂烟气脱硫技术及其主要工艺

简要介绍了我国二氧化硫的排放及其污染现状、燃煤电厂湿法、半干法、干法、可回收工艺和联合SO2／NOx工艺等五类烟气脱硫（FGD）技术及其主要的工艺，并对我国烟气脱硫技术的发展进行了探讨，指出我国烟气脱硫技术的发展应走国产化的道路，在具体的脱硫工艺的选择上应具体问题具体分析。     

电子束烟气脱硫技术及工业应用

文章对电子束脱硫技术的工艺流程、工艺原理,以及影响二氧化硫和氮氧化物脱除率主要因素的行为特征进行了概略性总结。通过对国内外典型工程实例的介绍,展示了电子束脱硫技术用于二氧化硫和氮氧化物脱除的工程应用现状。     

Toxic effects of acetochlor, methamidophos and their combination on nifH gene in soil

Toxic effects of two agrochemicals on nifH gene in agricultural black soil were investigated using denaturing gradient gel electrophoresis （DGGE） and sequencing approaches in a microcosm experiment. Changes of soil nifH gene diversity and composition were examined following the application of acetochlor, methamidophos and their combination. Acetochlor reduced the nifH gene diversity （both in gene richness and diversity index values） and caused changes in the nifH gene composition. The effects of acetochlor on nifH gene were strengthened as the concentration of acetochlor increased. Cluster analysis of DGGE banding patterns showed that nifH gene composition which had been affected by low concentration of acetochlor （50 mg/kg） recovered firstly. Methamidophos reduced nifH gene richness that except at 4 weeks. The medium concentration of methamidophos （150 mg/kg） caused the most apparent changes in nifH gene diversity at the first week while the high concentration of methamidophos （250 mg/kg） produced prominent effects on nifH gene diversity in the following weeks. Cluster analysis showed that minimal changes of nifH gene composition were found at 1 week and maximal changes at 4 weeks. Toxic effects of acetochlor and methamidophos combination on nifH gene were also apparent. Different nifH genes （bands） responded differently to the impact of agrochemicals： four individual bands were eliminated by the application of the agrochemicals, five bands became predominant by the stimulation of the agrochemicals, and four bands showed strong resistance to the influence of the agrochemicals. Fifteen prominent bands were partially sequenced, yielding 15 different nifH sequences, which were used for phylogenetic reconstructions. All sequences were affiliated with the alpha- and beta-proteobacteria, showing higher similarity to eight different diazotrophic genera.     

Arsenic uptake by arbuscular mycorrhizal maize （Zea mays L.） grown in an arsenic-contaminated soil with added phosphorus

The effects of arbuscular mycorrhizal (AM) fungus (Glomus mosseae) and phosphorus (P) addition (100 mg/kg soil) on arsenic (As) uptake by maize plants (Zea mays L.) from an As-contaminated soil were examined in a glasshouse experiment.Non-mycorrhizal and zero-P addition controls were included.Plant biomass and concentrations and uptake of As,P,and other nutrients,AM colonization,root lengths,and hyphal length densities were determined.The results indicated that addition of P significantly inhibited root colonization and development of extraradical mycelium.Root length and dry weight both increased markedly with mycorrhizal colonization under the zero-P treatments,but shoot and root biomass of AM plants was depressed by P application.AM fungal inoculation decreased shoot As concentrations when no P was added,and shoot and root As concentrations of AM plants increased 2.6 and 1.4 times with P addition,respectively.Shoot and root uptake of P,Mn,Cu,and Zn increased,but shoot Fe uptake decreased by 44.6%,with inoculation, when P was added.P addition reduced shoot P,Fe,Mn,Cu,and Zn uptake of AM plants,but increased root Fe and Mn uptake of the nonmycorrhizal ones.AM colonization therefore appeared to enhance plant tolerance to As in low P soil,and have some potential for the phytostabilization of As-contaminated soil,however,P application may introduce additional environmental risk by increasing soil As mobility.     

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.     

Potential of plant polyphenol oxidases in the decolorization and removal of textile and non-textile dyes

In this study an effort has been made to use plant polyphenol oxidases; potato （Solanum tuberosum） and brinjal （Solanum melongena）, for the treatment of various important dyes used in textile and other industries. The ammonium sulphate fractionated enzyme preparations were used to treat a number of dyes under various experimental conditions. Majority of the treated dyes were maximally decolorized at pH 3.0. Some of the dyes were quickly decolorized whereas others were marginally decolorized. The initial first hour was sufficient for the maximum decolorization of dyes. The rate of decolorization was quite slow on long treatment of dyes. Enhancement in the dye decolorization was noticed on increasing the concentration of enzymes. The complex mixtures of dyes were treated with both preparations of polyphenol oxidases in the buffers of varying pH values. Potato polyphenol oxidase was significantly more effective in decolorizing the dyes to higher extent as compared to the enzyme obtained from brinjal polyphenol oxidase. Decolorization of dyes and their mixtures, followed by the formation of an insoluble precipitate, which could be easily removed simply by centrifugation.     

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.     

Removal of heavy metals from sewage sludge by low costing chemical method and recycling in agriculture

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Organochlorine pesticides in soils under different land usage in the Taihu Lake region, China

A field study was conducted in the Taihu Lake region, China in 2004 to reveal the organochlorine pesticide concentrations in soils after the ban of these substances in the year 1983. Thirteen organochlorine pesticides (OCPs) were analyzed in soils from paddy field, tree land and fallow land. Total organochlorine pesticide residues were higher in agricultural soils than in uncultivated fallow land soils. Among all the pesticides, ΣDDX (DDD, DDE and DDT) had the highest concentration for all the soil samples, ranging from 3.10 ng/g to 166.55 ng/g with a mean value of 57.04 ng/g and followed by ΣHCH, ranging from 0.73 ng/g to 60.97 ng/g with a mean value of 24.06 ng/g. Dieldrin, endrin, HCB and α-endosulfan were also found in soils with less than 15 ng/g. Ratios of p,p'-(DDD DDE)/DDT in soils under three land usages were: paddy field ＞ tree land ＞ fallow land, indicating that land usage inlfuenced the degradation of DDT in soils. Ratios of p,p'-(DDD DDE)/DDT ＞1, showing aged residues of DDTs in soils of the Taihu Lake region. The results were discussed with data from a former study that showed very low actual concentrations of HCH and DDT in soils in the Taihu Lake region, but according to the chemical half-lives and their concentrations in soils in 1980s, the concentration of DDT in soils seemed to be underestimated. In any case our data show that the ban on the use of HCH and DDT resulted in a tremendous reduction of these pesticide residues in soils, but there are still high amounts of pesticide residues in soils, which need more remediation processes.     

Single and joint effects of pesticides and mercury on soil urease

The influence of two pesticides including chlorimuron-ethyl and furadan and mercury （Hg） on urease activity in 4 soils （meadow burozem and phaeozem） was investigated. The soils were exposed to various concentrations of the two pesticides and Hg individually and simultaneously. Results showed that there was a close relationship between urease activity and organic matter content in soil. Chlorimuron-ethyl and furadan could both activate urease in the 4 soils. The maximum increment of urease activity by chlorimuronethyl was up to 14%-18%. There was almost an equal increase （up to 13%-21%） in the urease activity by furadan. On the contrary, Hg markedly inhibited soil urease activity. A logarithmic equation was used to describe the relationship （P〈0.05） between the concentration of Hg and the activity of soil urease in the 4 tested soils. Semi-effect dose （ED50） values by the stress of Hg based on the inhibition of soil urease in the 4 soils were 88, 5.5, 24 and 20 mg/kg, respectively, according to the calculation of the corresponding equations. The interactive effect of chlorimuron-ethyl or furadan with metal Hg on soil urease was mainly synergic at the highest tested concentrations.