天津大港发电厂

<正>天津大港发电厂2014年上半年发电量完成29.62×108k W·h,供电煤耗累计完成336.50g/k W·h,机组综合厂用电率完成10.15%,机组发电水耗率完成0.403kg/k W·h。2013年节能量累计完成的65.7%"十二五"节能目标任务,并达到了国家及天津市规定的能耗限额考核要求。在环保改造期间,大港发电厂还承担了国家"863"科技项目——"300MW等级燃煤电厂PM2.5控制示范应用项目的研究"工作,通过替代单相电源、优化电场布置、改善除尘器通流等手段,使烟尘排放浓度由30⁵0mg/Nm3全面降至20mg/Nm3以下。其中,3#机组通过配合低温省煤器改造,烟尘排放浓度更是降到     

三缸三排汽200 MW汽轮机低压转子光轴供热改造的节能减排效益研究

该文结合当前的国家政策和电力行业深度挖潜、灵活性改造的发展需求,针对当前某电厂所在区域的供热现状进行了简要说明,对该电厂三缸三排汽200 MW汽轮机低压缸光轴改造原理进行了说明;结合改造经验,对机组经济性指标、节能量情况进行了测算,对项目的供热收益和灵活性收益进行了总结,对项目的环保效益进行了计算,说明光轴供热改造项目不仅具有良好的经济效益,还具有节能和环保的社会效益,更会对企业的可持续发展产生积极影响和促进作用.     

200MW纯凝机组低压转子光轴改造供热研究应用

针对一台200MW纯凝机组需要改造为供热机组,从供热技术方面进行了比较分析,选择了低压转子光轴供热改造方案,制定了供热改造措施。改后工业试验表明:供热期间,机组运行参数正常,在150MW负荷时,供热量为1098.91 GJ·h~(-1),发电煤耗率为158.55g·(kW·h)~(-1),较改前同样工况,发电煤耗率下降了186.52g·(kW·h)~(-1),达到了预期效果,为其他供热改造机组提供了借鉴经验。     

天津国电津能热电有限公司

<正>天津国电津能热电有限公司2014年上半年发电量完成16.43×108k W·h,发电煤耗完成290.33g/k W·h,供电煤耗完成302.03g/k W·h,综合厂用电率完成5.56%。2013年公司节能量完成1.39万吨,2011年至2013年累计完成节能量9.782万吨,提前两年完成了市经委下达的8.921万吨的"十二五"节能目标,通过了天津市万家企业节能量核查工作。完成了2013年度企业能源利用报告上报工作,及全国火电机组能效对标及全国300MW级机组竞赛数据测算填报工作。完成了企业能     

200MW燃煤机组SCR脱硝改造关键技术问题解析

目前,国内200 MW机组SCR脱硝改造尚无样板工程及改造先例。200 MW机组由于其独特地设计,同300 MW以上等级机组相比,脱硝改造的技术方式与改造内容均有较大的差异。文章从国内200 MW机组脱硝改造实际情况出发,从设计参数选取、还原剂选择、SCR反应器布置方式、低氮燃烧器改造、空预器改造及引风机改造、厂用变压器系统改造等关键问题进行了技术分析并提出可行建议,为同等级机组脱硝改造工作提供方法与经验。     

天津市火电专委会节能工作会议报告

<正>天津国华盘山发电公司2014年上半年发电量完成26.6亿千瓦时;上半年机组供电煤耗完成313g/kW·h,机组综合厂用电率完成6.38%,发电水耗完成1.68 kg/kW·h,主要指标完成年度计划值和进度值。2014年上半年主要完成了2#机组的A级检修工作,完成了汽泵组改造、引风机改造、送风机改造、脱硝系统改造、少油点火改造、喷燃器改造项目,机组改造后机组供电煤耗降低7.3 g/kW·h;完成2#机组改造后性能考核试验,试验内容涉及汽泵组改     

火力发电厂除尘布袋（电袋）节能措施应用

目前国家节能环保对火电厂指标越来越严格以来,普遍用于燃煤电厂的静电除尘器不能满足现有国家排放标准。至2010年已有近200台布袋除尘器投入运行,更多200MW、350MW新建或改造机组采用新型布袋除尘器,其中最大的机组为河南某地600MW机组。     

350 MW机组低温省煤器系统节能减排效益分析

降低煤耗和碳排放是中国煤电行业在"十三五"期间面临的重大挑战。本研究以某350 MW典型亚临界机组为研究对象,在空预器和电除尘器之间的烟道设计加装低温省煤器,用等效热降法计算了系统在THA工况下的节能减排收益。结果表明:机组发电标煤耗和供电煤耗分别降低了2.8 g/kW·h和2.5g/kW·h,当年等效运行小时数为4500时,每年可降低标煤耗3997.7 t,节约燃料成本319.8万元,有着显著的节能效益和经济收益;机姐每年排碳量可减少3167.0 t,大约相当于78.2 ha中国森林的平均碳俘获量,在国内外碳排放交易市场正在建立与完善的背景下,系统逐年的减排量有着巨大的潜在收益。     

关于火电厂绿色评价指标的探讨

由于传统的“供电煤耗率”并不能反映机组对环境影响的大小,因此提出了“绿色供电煤耗率”这个概念,并采用“绿色性能因子”来评价火电机组性能包括环境因素在内的总体表现。为了进一步诊断出机组环境损耗的真正原因,为运行提供指导,提出了,“环境损耗因子”、“环境局部影响因子”等概念。最后以国产两台燃烧不同煤种的600MW机组为例,利用所提出的绿色指标,对机组在某段时间内的运行状况分别进行了全面评价并作了对比分析。     

燃煤电厂脱硫技术及超低排放改造费效分析

基于燃煤电厂二氧化硫排放现状及超低排放的要求,构建石灰石-石膏法脱硫费效计算模型,分别分析机组容量、年运行小时数、不同SO_2排放限值及托盘塔改造对成本效益的影响,以"费用最小化、效益最大化"为原则,寻求节能减排新途径。结果表明:在煤炭含硫量和脱硫效率一定时,100 MW、200 MW、300 MW、600 MW和1 000 MW机组的减排量分别为3.47万,5.5万,8.2万,15.5万,25万t,呈逐渐增大趋势,同时,费效比逐渐减小,说明大容量机组环境、经济效益明显;同一机组容量,脱硫成本与年利用时间呈负相关;SO_2排放标准越严格,吨SO_2脱除成本和单位发电量运行成本越高;托盘塔超低排放改造技术经济可行,费效比<1,减排效益明显,可作为燃煤电厂脱硫设施改造的重点技术。     

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.     

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.     

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

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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.     

Isolation and preliminary characterization of a 3-chlorobenzoate degrading bacteria

A study was conducted to compare the diversity of 2-, 3-, and 4-chlorobenzoate degraders in two pristine soils and one contaminated sewage sludge. These samples contained strikingly different populations of mono-chlorobenzoate degraders. Although fewer cultures were isolated in the uncontaminated soils than contaminated one, the ability of microbial populations to mineralize chlorobenzoate was widespread. The 3- and 4-chlorobenzoate degraders were more diverse than the 2-chlorobenzoate degraders. One of the strains isolated from the sewage sludge was obtained. Based on its phenotype, chemotaxonomic properties and 16S rRNA gene, the organism S-7 was classified as Rhodococcus erythropolis. The strain can grow at temperature from 4 to 37℃. It can utilize several （halo）aromatic compounds. Moreover, strain S-7 can grow and use 3-chlorobenzoate as sole carbon source in a temperatures range of 10-30℃ with stoichiometric release of chloride ions. The psychrotolerant ability was significant for bioremediation in low temperature regions. Catechol and chlorocatechol 1,2-dioxygenase activities were present in cell free extracts of the strain, but no （chloro）catechol 2,3- dioxygenase activities was detected. Spectral conversion assays with extracts from R. erythropolis S-7 showed accumulation of a compound with a similar UV spectrum as chloro-cis,cis-muconate from 3-chlorobenzoate. On the basis of these results, we proposed that S-7 degraded 3-chlorobenzoate through the modified ortho-cleave pathway.     

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.     

Sorption of 1-naphthol by plant cuticular fractions

The contribution of aliphatic-rich plant biopolymer to sorption of hydrophobic organic compounds is significantly important because of their preservation and accumulation in the soil environment,but sorption mechanism is still not fully understood.In this study, sorption of 1-naphthol by plant cuticular fractions was examined to better understand the contributions of respective fraction.Toward this end,cuticular materials were isolated from the fruits of tomato by chemical method.The tomato cuticle sheet consisted of waxes (6.5 wt%),cuticular monomer (69.5 wt%),and polysaccharide (24.0 wt%).Isotherms of l-naphthol to the cuticular fractions were nonlinear (N value (0.82-0.90)) at the whole tested concentration ranges.The KodKow ratios for bulk cuticle (TC1),dewaxed cuticle (TC2),cutin (TC4),and desugared cuticle (TC5) were larger than unity,suggested that tomato bulk cuticle and cutin are much powerful solption medium.Sorption capability of cutin (TC4) was 2.4 times higher than the nonsaponifiable fraction (TC3).The 1-naphthol interactions with tomato cuticular materials were governed by both hydrophobic-type interactions and polar (H-bonding) interactions. Removal of the wax and polysaccharide materials from the bulk tomato cuticle caused a significant increase in the sorption ability of the cuticular material.There was a linear negative trend between K_(oc) values and the amount of polysaccharides or fraction's polarities ((N O)/C);while a linear positive relationship between K_(oc) values and the content of cutin monomer (linear R~2=0.993) was observed for present in the cuticular fractions.Predominant sorbent of the hydrophobic organic compounds (HOCs) in the plant cuticular fraction was the cutin monomer,contributing to 91.7% of the total sorption of tomato bulk cuticle.     

Alterations of organ histopathology and metallolhionein mRNA expression in silver barb, Puntius gonionotus during subchronic cadmium exposure

Common silver barb,Puntius gonionotus,exposed to the nominal concentration of 0.06 mg/L Cd for 60 d,were assessed for histopathological alterations(gills,liver and kidney),metal accumulation,and metallothionein(MT)mRNA expression.Fish exhibited pathological symptoms such as hypertrophy and hyperplasia of primary and secondary gill lamellae,vacuolization in hepatocytes,and prominent tubular and glomerular damage in the kidney.In addition,kidney accumulated the highest content of cadmium,more than gills and liver.Expression of MT mRNA was increased in both liver and kidney of treated fish.Hepatic MT levels remained high after fish were removed to Cd-free water.In contrast,MT expression in kidney was peaked after 28 d of treatment and drastically dropped when fish were removed to Cd-free water.The high concentrations of Cd in hepatic tissues indicated an accumulation site or permanent damage on this tissue.     

Seed selections for crystallization of calcium phosphate for phosphorus recovery

Seed induces and promotes the crystallization of calcium phosphate, and acts as carrier of the recovered phosphorus （P）. In order to select suitable seed for P recovery from wastewater, three seeds including Apatite （AP）, Juraperle （JP） and phosphate-modified Juraperle （M-JP） were tested and compared. Batch and fixed-bed column experiments of seeded crystallization of calcium phosphate were undertaken by using synthetic wastewater with 10 mg/L P phosphate. It shows that AP has bad enduring property in the crystallization process, while JP has better performance for multiple uses, and M-JP is a hopeful seed for P recovery by crystallization of calcium phosphate.