温度对氨法脱硫率影响的实验研究

对使用氨（NH3）脱除烟气中气态污染物的技术进行了分析和总结，认为氨洗涤法洗涤净化烟气是一种很有前景的方法，并就温度对SO2脱除率的影响进行了实验研究。实验研究结果显示，当温度超过54℃时，NH3对SO2仍有很高的脱除率。并根据实验结果建议，在实际氨法脱硫工程中，脱硫过程温度宜控制在60℃以下或在80℃以上。     

NaHCO_3和石灰干式净化焚烧烟气中酸性气体的效果与经济性

在热态试验台上研究了石灰和NaHCO3作为吸附剂时,焚烧烟气中HCl和SO2的净化效果。实验研究表明,HCl的排放达标是更主要的任务,在HCl的初始浓度不高于70mg/m3时,NaHCO3和石灰与焚烧烟气中HCl的化学量比(NSR)在4.0以上,HCl和SO2的排放才能满足欧盟2000标准。经济性方面,虽然NaHCO3比石灰的价格贵,但NaHCO3对保证排放标准更为可靠。     

村镇生活垃圾与秸秆混合焚烧过程中多环芳烃(PAHs)释放特征

为了解我国农村地区生活垃圾与玉米秸秆焚烧处置过程烟气中多环芳烃(PAHs)释放特征,对我国农村地区生活垃圾可燃组分以及生活垃圾与玉米秸秆混合焚烧组分在焚烧过程烟气中PAHs化合物释放特征进行分析,利用气相色谱-质谱仪(GC-MS)对样品中的16种PAHs进行分析,研究气态以及颗粒态PAHs的释放因子、环数比例、气固态分配以及排放特征值.结果表明气态PAHs排放因子为当垃圾与秸秆混合比例为1∶2时PAHs的总量最多,而颗粒态为当垃圾与秸秆混合比例为1∶3时PAHs的总量最多;气态PAHs主要集中于2～3环低环数化合物,颗粒态PAHs则主要以中低环数(3～4环)化合物为主,本研究为促进我国村镇生活垃圾处理与资源化运用提供理论依据.     

北京市民用燃煤烟气中气态污染物排放特征

以北京远郊农村居民常用的蜂窝煤、煤球、烟煤散煤为实验用煤,开展燃烧实验.研究了烟气无机污染物排放因子、VOCs释放情况.结果表明在充分燃烧的条件下,蜂窝煤、煤球、烟煤气态污染物SO2排放因子分别为1.50、1.91、1.62kg·t~(-1);NOx排放因子分别为0.420、0.901、2.20 kg·t~(-1);CO排放因子分别为22.4、37.3、87.3 kg·t~(-1).燃烧排放的NOx和CO的排放因子顺序关系为:烟煤煤球蜂窝煤;SO2的排放因子大小顺序分别为:煤球烟煤蜂窝煤.获得了北京市2014年3种民用煤燃烧排放的气态污染物的排放清单,烟煤散煤排放的SO2超过了0.55万t,NOx超过了0.75万t,CO超过了29万t.3种煤质燃烧过程中点火和封火阶段VOCs排放浓度相对较高,各阶段VOCs排放因子为点火阶段最高,封火阶段次之.     

流化床焚烧含盐苯胺废液的NOx排放特性

在流化床焚烧实验装置上进行含盐苯胺(C6H5NH2)废液的焚烧实验研究,用IMR-IMR2800P废气分析仪对焚烧尾气成分进行了在线监测,考察了焚烧工艺条件对NOx排放浓度的影响规律.结果显示:采用分级燃烧工艺和提高焚烧温度,可以降低NOx浓度;增大进料速率却导致NOx排放浓度的增加.当过剩空气系数(α)低于1.0时,NOx排放浓度随着α的增大急剧上升;大于1.1时,NOx排放浓度随α增加而减小.苯胺废液高温焚烧时添加氯化钠能降低NOx排放.     

城市生活垃圾焚烧对大气的污染问题

本文对我国城市有机混合垃圾经模化后,在过剩空气系数α?2,温度在700～900℃条件下焚烧的气态排放物进行了定性和定量分析.实验结果表明:烟气呈碱性,主要污染物NH_2的排放浓度最高.HCl次之,NO_x<100ppm,SO_x<1ppm,H_2S<10ppm.     

垃圾焚烧中硫化合物对重金属Pb迁移分布影响

采用管式炉和模拟垃圾对垃圾焚烧中硫化合物(包括S、Na2S、Na2SO3、Na2SO4)、焚烧温度、重金属初始加入浓度以及焚烧停留时间对Pb迁移分布的影响进行了研究.使用ICP-AES分析技术(美国EPA消解方法)对重金属浓度进行测量.结果表明,垃圾焚烧中4种硫化合物的加入均使得Pb在底渣中的分布比例比未加入硫化合物时的分布比例降低.Pb在底渣中的分布比例随加入S和Na2S含量的增加而减少,相应地在飞灰中的分布随S和Na2S加入量的增加而增加,而Pb的迁移分布比例受Na2SO3和Na2SO4含量变化的影响不显著.温度的升高使得Pb向飞灰中的分布比例逐渐增加,整个试验温度范围内Pb在烟气中的分布均为0.初始浓度的增加也使Pb在底渣中的分布比例逐渐升高,飞灰中的分布比例逐渐下降.停留时间的增加会使得Pb在底渣中的分布比例降低,相应地在飞灰中的分布比例会增加.     

华北地区乡村站点(曲周)夏季PM2.5中二次无机组分的生成机制与来源解析

利用大气PM2.5水溶性组分及其气态前体物在线测量系统(GAC-IC)于2014年6月9日~7月11日对华北地区乡村站点曲周大气PM2.5中水溶性组分及其气态前体物进行了在线测量,分析了PM2.5中水溶性组分与气态前体物日变化规律及其相互作用,探讨了当地细颗粒物的气粒转化机制并分析了其来源.结果表明夏季曲周大气PM2.5中水溶性无机离子与相关气态前体物的浓度呈现明显的日变化规律.观测期间,PM2.5中SO2-4、NH+4和NO-3的平均浓度分别是26.28、18.08和16.36μg·m-3,是PM2.5中最主要的水溶性无机离子,约占PM2.5质量浓度的76.23%;气态前体物中,NH3浓度明显偏高、平均值为44.85μg·m-3,主要来源于当地的农业活动排放;硫氧化率(SOR)和氮氧化率(NOR)平均值分别是0.60和0.30,表现出明显的二次污染特征.经相关性分析发现:曲周大气PM2.5中NH+4与NO-3、SO2-4有良好的相关性,且表现为富氨状态,NH+4以(NH4)2SO4形式存在,NO-3的生成主要受HNO3的限制.对NH4NO3平衡进行研究发现:与夜间相反,白天曲周大气环境不利于NH4NO3生成和保持.结果也表明,二次转化是曲周夏季细颗粒物的主要来源,堆肥与农田释放的NH3是导致高浓度二次无机颗粒物(SNA)的重要因素.     

SO2排放造成的森林损失计算:以湖南省为例

SO2排放对我国的森林生态系统造成了严重的损害,因而损失计算对于SO2控制具有重要意义,但是目前仍缺乏有效的方法计算不同排放水平下的森林损失.本研究以硫沉降超临界负荷作为计算森林损失的参数,推导了适用于我国硫沉降导致森林损失的剂量-响应函数,并以湖南省为例,以1995为基准年,计算了2000年～2020年高中低3种SO2排放方案下的森林损失.研究结果表明,随着今后湖南省经济和能源消费的增长,森林损失将继续增加.高排放方案下2020年SO2排放将增长1.2倍,但森林损失增长4.3倍,边际损失高于6000元/t.在当前排放水平下对SO2排放进行削减,边际效益达到1500元/t,因此控制SO2具有显著的经济效益.对湖南案例的不确定性分析显示,计算方法有较高的可靠性.研究结果为区域SO2控制策略的优化提供了支持.     

污泥焚烧项目环境监理钙硫比核算应用实践研究

在污泥焚烧项目环境监理过程中,通过核算钙硫摩尔比考察或佐证二氧化硫的去除能力及效果.根据钙硫比核算需要收集项目相关生产报表,并对污泥焚烧过程中的钙硫摩尔比进行核算.通过对钙硫比的合理性进行分析,进而考察污泥焚烧过程中二氧化硫产生情况及达标排放情况,提升环境监理工作深度.数据来源为企业实际生产报表,分析方法为钙硫元素摩尔量理论反应值、质量平衡、热量平衡.通过实际数据核算分析发现,污泥焚烧项目中的钙硫元素摩尔比明显低于理论设计值,污泥中硫在焚烧过程中转化成SO2的比例约为64.52%.     

Effects of two sludge application on fractionation and phytotoxicity of zinc and copper in the soil

The potential harm of heavy metals is a primary concern in application of sludge to the agricultural land. A pot experiment was conducted to evaluate the effect of two sludges on fractionation of Zn and Cu in soil and their phytotoxicity to pakchoi. The loamy soil was mixed with 0%, 20%, 40%, 60% and 80% (by weight) of digested sewage sludge (SS) and composted sludge (SC). The additions of both sludges caused a significant raise in all fractions, resulting in that exchangeable (EXCH) and organic bound (OM) became predominance of Zn and organic bound Cu occupied the largest portion. There was more available amount of Zn and Cu in SS treatments than SC treatments. During the pot experiment, the concentration of Zn in EXCH, carbonate (CAR) and OM and Cu in EXCH and OM fractions decreased in all treatments, so their bioavailability reduced. Germination rate and plant biomass decreased when the addition rate was high and the best yield appeared in 20% mixtures at the harvest of pakchoi. The two sludges increased tissue contents of Zn and Cu especially in the SS treatments. Zn in pakchoi was not only in relationship to ΔEXCH and ΔCAR forms but also in ΔOM forms in the sludge-soil mixtures. Tissue content of Cu in pakchoi grown on SC-soils could not be predicted by ΔEXCH. These correlation rates between Zn and Cu accumulation in pakchoi and variation of different fractions increased with time, which might indicate that sludges represented stronger impacts on the plant in long-term land application.     

Intraspecific differences in effects of co-contamination of cadmium and

A hydroponic experiment was carried out to study intraspecific differences in the effects of different concentrations of cadmium (Cd)(0-10 mg/L) and arsenate (As(V)) (0-8 mg/L) on the growth parameters and accumulation of Cd and As in six wheat varieties Jing-9428, Duokang-1, Jingdong-11, Jing-411, Jingdong-8 and Zhongmai-8. The endpoints of wheat seedlings, including seed germination,biomass, root length and shoot height, decreased with increasing the Cd and As concentrations. Significant differences in seed germination, biomass, root length, shoot height and the accumulation of Cd and As were observed between the treatments and among the varieties (p ＜ 0.05). The lethal dosage 50% were about 20, 80, 60, 60, 80 and 20 mg As/L for Jing-9428, Duokang-1, Jingdong-11,Jing-411, Jingdong-8 and Zhongmai-8, respectively, and the corresponding values for Cd were about 30, 80, 20, 40, 60 and 10 mg Cd/L, respectively. Among the six varieties, Duokang-1 was found to be the most resistant to Cd and As toxicity, and Zhongmai-8 was the most sensitive to Cd and As co-contamination. The resistance of the six varieties was found dependant on the seedling uptake of Cd and As. Duokang-1 was the most suitable for cultivation in Cd and As co-contaminated soils.     

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.     

Degradation of metabolites accumulated of benzo[a]pyrene by coupling Penicillium Chrysogenum with KMnO4

Several main metabolites of benzo[a]pyrene （BaP） formed by Penicillium chrysogenum, Benzo[a]pyrene-1,6-quinone （BP 1,6- quinone）, trans-7,8-dihydroxy-7,8-dihydrobenzo[a]pyrene （BP 7,8-diol）, 3-hydroxybenzo[a]pyrene （3-OHBP）, were identified by high-performance liquid chromatography （HPLC）. The three metabolites were liable to be accumulated and were hardly further metabolized because of their toxicity to microorganisms. However, their further degradation was essential for the complete degradation of BaP. To enhance their degradation, two methods, degradation by coupling Penicillium chrysogenum with KMnO4 and degradation only by Penicillium chrysogenum, were compared; Meanwhile, the parameters of degradation in the superior method were optimized. The results showed that （1） the method of coupling Penicillium chrysogenum with KMnO4 was better and was the first method to be used in the degradation of BaP and its metabolites; （2） the metabolite, BP 1,6-quinone was the most liable to be accumulated in pure cultures; （3） the effect of degradation was the best when the concentration of KMnO4 in the cultures was 0.01% （w/v）, concentration of the three compounds was 5 mg/L and pH was 6.2. Based on the experimental results, a novel concept with regard to the bioremediation of BaP-contaminated environment was discussed, considering the influence on environmental toxicity of the accumulated metabolites.     

Impact of atrazine and nitrogen fertilizers on the sorption of chlorotoluron in soil and model sorbents

Sorption of chlorotoluron in ammonium sulfate, urea and atrazine multi-solutes system was investigated by batch experiments. The results showed application of nitrogen fertilizers to the soil could affect the behavior of chlorotoluron. At the same concentration of N, sorption of chlorotoluron decreased as the concentration of atrazine increased on the day 0 and 6 in soil, respectively. The sorption of chlorotoluron increased from 0 to 6 d when soils were preincubated with deionized water, ammonium sulfate and urea solution for 6 d. That indicated incubation time was one of the most important factors for the sorption of chlorotoluron in nitrogen fertilizers treatments. The individual sorption isotherms of chlorotoluron in rubbery polymer and silica were strictly linear in single solute system, but there were competition sorption between pesticides or between pesticides and nitrogen fertilizers. That indicated the sorption taken place by concurrent solid-phase dissolution mechanism and sorption on the interface of water-organic matter or water-mineral matter.     

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.