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921.
垃圾渗滤液水质十分复杂,不仅含有耗氧有机污染物,还含有各类金属离子和植物营养素(氨氮等),工业垃圾渗滤液中还会含有有毒有害的污染物;其中有难以生物降解的萘、菲等非氯化芳香组化合物、氯化芳香组化合物、磷酸酯、邻苯二甲酸酯、酚类化合物和苯胺类化合物等;垃圾渗滤液中含有十多种金属离子,其中的重金属离子会对微生物产生抑制作用;氨氮含量高,C/N比例失调,磷元素缺乏,给生物处理带来一定的难度.本文开发了UASB-GAIA-BAF一体化生化处理工艺,以节约成本,提高垃圾渗滤液中有机物去除率,加快反应速率为目的,对厌氧生物处理、高级氧化处理、固定化生物滤池组合工艺降解垃圾渗滤液进行了初步设计和工程应用.处理工艺具有工艺成熟、投资省、运行费用低、污泥产生量小的优点. 相似文献
922.
Carbonyl compounds are important intermediates in atmospheric photochemistry, but their primary sources are still not understood well. In this work, carbonyls, hydrocarbons, and alkyl nitrates were continuously measured during November 2011 at a rural site in the Yangtze River Delta region of China. Mixing ratios of carbonyls and hydrocarbons showed large fluctuations during the entire measurement. The average level for total measured volatile organic compounds during the pollution episode from 25th to 27th November, 2011 was 91.6 ppb, about 7 times the value for the clean period of 7th–8th, November, 2011. To preliminarily identify toluene sources at this site, the emission ratio of toluene to benzene (T/B) during the pollution episode was determined based on photochemical ages derived from the relationship of alkyl nitrates to their parent alkanes. The calculated T/B was 5.8 ppb/ppb, significantly higher than the values of 0.2–1.7 ppb/ppb for vehicular exhaust and other combustion sources, indicating the dominant influence of industrial emissions on ambient toluene. The contributions of industrial sources to ambient carbonyls were then calculated using a multiple linear regression fit model that used toluene and alkyl nitrates as respective tracers for industrial emission and secondary production. During the pollution episode, 18.5%, 69.0%, and 52.9% of measured formaldehyde, acetaldehyde, and acetone were considered to be attributable to industrial emissions. The emission ratios relative to toluene for formaldehyde, acetaldehyde, and acetone were determined to be 0.10, 0.20 and 0.40 ppb/ppb, respectively. More research on industrial carbonyl emission characteristics is needed to understand carbonyl sources better. 相似文献
923.
Microbial diversity and abundance in bioaerosols of a coal mine were analyzed based on 454 pyrosequencing and real-time polymerase chain reaction(PCR). A total of 37,191 high quality sequences were obtained and could be classified into 531, 1730 and 448 operational taxonomic units respectively for archaea, bacteria and fungi at 97% sequence similarity. The Shannon diversity index for archaea, bacteria and fungi was respectively 4.71, 6.29 and 3.86, indicating a high diversity in coal mine bioaerosols. Crenarchaeota, Proteobacteria and Ascomycota were the dominant phyla for archaea, bacteria and fungi, respectively. The concentrations of total archaea, bacteria and fungi were 1.44 × 108, 1.02 × 108 and 9.60 × 104cells/m3, respectively.Methanotrophs observed in bioaerosols suggested possible methane oxidation in the coal mine. The identified potential pathogens to coal miners, such as Acinetobacter schindleri,Aeromonas cavernicola, Alternaria alternata, Aspergillus penicillioides, Cladosporium cladosporioides,and Penicillium brevicompactum were also observed. This was the first investigation of microbial diversity and abundance in coal mine bioaerosols. The investigation of microbial communities would be favorable in promoting the progress of methane control based on microbial technique and concern on coal miners’ health. 相似文献
924.
典型环境中三种自然环境加速试验方法的环境强化效果分析 总被引:5,自引:5,他引:0
目的研究自然环境加速试验方法的环境强化效果。方法通过分析实时监测获得的典型环境不同自然环境加速试验装置中,温湿度环境因素变化数据,找出典型环境中不同自然环境加速试验装置内部的温湿度环境因素变化规律,计算得到典型环境中不同自然环境加速试验方法对温湿度环境因素的强化效果。结果得到了典型环境中不同自然环境加速试验装置的特征温湿度变化规律曲线图。结论玻璃框、黑箱、强制通风玻璃框等3种自然环境加速试验装置对自然环境的光照热效应有明显的强化作用,其内部温度变化梯度大小与环境中太阳辐射量大小相关。 相似文献
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928.
2011年春季沙尘天气影响下上海大气颗粒物及其化学组分的变化特征 总被引:7,自引:4,他引:3
于2011年4月28日~5月18日对上海大气中颗粒物的质量浓度及细粒子中的化学组分进行了连续观测,获得了上海受春季沙尘天气影响下大气颗粒物质量浓度和主要化学组分特征.结果表明,沙尘天气中PM10和PM2.5的质量浓度显著高于非沙尘天,最高日均浓度分别达到787.2μg·m-3和139.5μg·m-3,PM2.5/PM10的均值为(32.9±14.6)%(15.6%~85.1%);总水溶性无机离子(TWSⅡ)占PM2.5的质量分数为(27.2±19.2)%(4.8%~80.8%),二次组分SNA(SO2-4、NO-3、NH+4)占TWSⅡ的(76.9±13.9)%(41.9%~94.2%),TWSⅡ和SNA对PM2.5的贡献均小于非沙尘天,而Ca2+的含量比却有明显上升.非沙尘天测得的OC/EC值高于强沙尘天,但低于弱沙尘天.此外分析还得到,沙尘中的高矿尘粒子具有酸性缓冲作用,使得沙尘天颗粒的碱性强于沙尘发生前.非沙尘天SO2-4、NO-3主要以NH4HSO4、(NH4)2SO4和NH4NO3的形式存在,沙尘天还会与其他矿物离子结合. 相似文献
929.
腐殖酸改性针铁矿对铀U(Ⅵ)的吸附性能及机理研究 总被引:2,自引:1,他引:1
通过人工合成的方法制得腐殖酸改性针铁矿(HA-α-FeOOH),考察了吸附时间、吸附剂用量、U(Ⅵ)初始浓度和pH值等因素对吸附U(Ⅵ)过程的影响.同时,利用傅里叶红外光谱(FTIR)、扫描电镜(SEM)和X射线能谱(EDS)分析了其对U(Ⅵ)的吸附机理.试验结果表明,在25℃、pH为4的条件下,腐殖酸改性针铁矿作用4 h对5 mg·L-1的含铀废水的去除率几乎达到100%.Freundlich等温吸附模型、准二级动力学模型对吸附过程的拟合效果较好,主要吸附模式为多层吸附;改性针铁矿对U(Ⅵ)的吸附是自发的吸热反应.SEM-EDS和FIIR分析结果表明,改性针铁矿吸附U(Ⅵ)的机理主要表现为内层络合作用及离子交换,与U(Ⅵ)作用的基团主要是羟基、酚羟基和羧基. 相似文献
930.
Optimization of wastewater treatment alternative selection by hierarchy grey relational analysis 总被引:14,自引:0,他引:14
This paper describes an innovative systematic approach, namely hierarchy grey relational analysis for optimal selection of wastewater treatment alternatives, based on the application of analytic hierarchy process (AHP) and grey relational analysis (GRA). It can be applied for complicated multicriteria decision-making to obtain scientific and reasonable results. The effectiveness of this approach was verified through a real case study. Four wastewater treatment alternatives (A(2)/O, triple oxidation ditch, anaerobic single oxidation ditch and SBR) were evaluated and compared against multiple economic, technical and administrative performance criteria, including capital cost, operation and maintenance (O and M) cost, land area, removal of nitrogenous and phosphorous pollutants, sludge disposal effect, stability of plant operation, maturity of technology and professional skills required for O and M. The result illustrated that the anaerobic single oxidation ditch was the optimal scheme and would obtain the maximum general benefits for the wastewater treatment plant to be constructed. 相似文献