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311.
Four kinds of woods used for residential heating in Australia were selected and burned under two burning conditions in a domestic wood heater installed in a laboratory. The selected wood species included pine (Pinus radiata), red gum (Eucalvptus camaldulensis), sugar gum (Eucalyptus cladocalyx) and yellow box (Eucalyptus melliodora). The two different burning conditions represented fast burning and slow burning, with the air inlet of the combustion chamber respectively 'full open' and 'half open'. By sampling and analysing particulate and gaseous emissions from the burning of each load of wood under defined experimental conditions, PAHs emissions and their profiles in the particulate and gaseous phases were obtained. 16 species out of the 18 selected PAHs were detected. Of these, seven species were detected in the gaseous phase and most were lower molecular weight compounds.Similarly, more than 10 species of PAHs were detected in the particulate phase and these were mostly heavier molecular weight compounds. Under both burning conditions, emission levels for total PAHs and total genotoxic PAHs were the highest for pine and lowest for sugar gum, with red gum being the second highest, followed by yellow box. Using the specific sampling method, gaseous PAHs accounted for above 90% mass fraction of total PAHs in comparison to particulate PAHs (10%). The majority of the genotoxic PAHs were present in the particulate phase. PAHs emission levels in slow burning conditions were generally higher than those in fast burning conditions. 相似文献
312.
根据染料废水的特点 ,研究了自制产品新型氧化 混凝剂处理染料废水的情况 ,探索了药剂用量、pH值等因素对COD、色度去除率的影响。试验表明 ,当pH >10、“染清”氧化 混凝剂的加入量万分之三左右、絮凝时间 6min、静置沉淀3 5min时 ,该药剂对染料废水具有良好的效果 ,COD和色度的去除率最高分别可达 97%和 86% ,从而证明该方法对于染料废水的处理是可行的。该处理工艺设备简单 ,系统运行稳定 ,操作方便 ,成本低 相似文献
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316.
This paper presents the incineration tests of municipal solid waste (MSW) in a fluidized bed and the adsorption of activated carbon (AC) on polycyclic aromatic hydrocarbons (PAHs). An extraction and high performance liquid chromatography (HPLC) technique was used to analyze the concentrations of the 16 US EPA specified PAHs contained in raw MSW, flue gas, fly ash, and bottom ash. The aim of this work was to decide the influence of AC on the distribution of PAHs during the incineration of MSW. Experimental researches show that there were a few PAHs in MSW and bottom ash. With the increase of AC feeding rate, the concentrations of three- to six-ring PAHs in fly ash increased, and the concentration of two-ring PAH decreased. The total-PAHs in flue gas were dominated by three-, and four-ring PAHs, but a few two-, five-ring PAHs and no six-ring PAHs were found. PAHs could be removed effectively from flue gas by using in-duct AC injection and the removal efficiencies of PAHs were about 76-91%. In addition, the total toxic equivalent (TEQ) concentrations of PAH in raw MSW, bottom ash, fly ash, and flue gas were 1.24 mg TEQ kg-1, 0.25 mg TEQ kg-1, 6.89-9.67 mg TEQ kg-1, and 0.36-1.50 microg TEQ Nm-3, respectively. 相似文献
317.
高级氧化法脱除PVA浆料的清洁生产新工艺研究 总被引:3,自引:0,他引:3
为了研究高级氧化法脱除聚乙烯醇(PVA)浆料清洁生产新工艺的可行性,研究了3种高级氧化法UV/H2O2、UV/TiO2、Nation-Fe^2+/H2O2对含PVA溶液的氧化降解,其降解效果依次为iUV/H2O2〉Nation-Fe^2+/H2O2〉UV/TiO2。对于UV/H2O2法,PVA降解速率与H2O2的初始浓度成正相关,且H2O2浓度为2.95mmol/L时14min内就能使PVA的去除率达到98%;pH和温度对PVA的氧化降解效果影响不明显。在此基础上,对建立在高级氧化法基础上的退浆新工艺进行了探讨,结果表明,在65℃和75℃下,高级氧化法条件下的纯棉织物PVA退浆率分别达到70.16%和95.65%;该法不仅可以促进PVA从纯棉织物上的脱附,而且可以达到对PVA的较高降解效果,使得所排退浆废水的生化处理难度明显降低。 相似文献
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319.
河流水质的动态马尔柯夫评价 总被引:3,自引:0,他引:3
根据马尔柯夫过程的原理,在水质级别评价结果的基础之上,构造水质变化的概率转移矩阵,并对转移概率赋权计算绝对进步度,然后在此基础上引出相对进步度的概念,用相对进步度来评价河流水质在一段时期内的变化程度.运用该方法计算了中国四大河流2005年的水质相对进步度,并对计算结果进行了分析. 相似文献
320.
Figueira R Pacheco AM Sousa AJ Catarino F 《Environmental pollution (Barking, Essex : 1987)》2002,119(1):69-78
Blubber collected from beluga whales and ringed seals during subsistence hunts in the southern Baffin Island region of the Canadian Arctic were analysed for polychlorinated naphthalenes and eight planar PCB congeners (mono-ortho PCBs: 105, 114, 118 and 156; non-ortho PCBs: 77, 81, 126, 169). SigmaPCN (3-7 Cl) concentrations in blubber ranged from 35.9-383 pg/g (lipid weight; lw) in beluga and 35.4-71.3 pg/g (lw) in ringed seal. These represent the first measurements of PCNs in marine mammals in the Canadian Arctic, mammals which are an important part of the traditional diet of the indigenous population. SigmaCoplPCB concentrations were much higher, ranging from 15.5-317 ng/g (lw) in beluga whale blubber and 16.5-40.9 ng/g (lw) in ringed seal blubber. PCNs and coplanar PCBs both exhibit dioxin-like toxicity. Although average sigmaPCN concentrations were less than 1% of sigmaCoplPCBs, PCNs contribute up to 11% of TEQ relative to the coplanar PCBs based on TEFs determined by H4IIE enzyme assays. 相似文献