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61.
广州李坑生活垃圾填埋场周围植被现状调查与影响分析   总被引:7,自引:0,他引:7  
为对垃圾填埋场封场后如何进行生态恢复研究提供基础资料,对超负荷运转中的广州市李坑生活垃圾填埋场周围的植被现状进行了调查,测算了物种量、覆盖度、污染状况等。同时运用植被覆盖度、结构、物种量和相对物种量等级评价以及对Zn、Cd等6种污染物的质量指数进行了评价。结果表明,所调查填埋场场区及灌区内有轻度污染,而场外与灌区外则相对较轻或无污染。  相似文献   
62.
农业草类废物既是一种废弃物,也是一种资源,由于其富含有机质,可通过厌氧生物降解产生沼气。本文研究了农业草类废物的好氧预处理对其固含量成分,生物沼气产生潜力(BMP),甲烷浓度,产气速率的影响进行了研究;并计算了作为一级反应的反应速率常数,其结果表明模型与实验值一致性较好。  相似文献   
63.
The association of the direct-acting mutagenicity of soluble organic fraction of airborne particles toward Salmonella typhimurium YG1024 strain with the direct emission was investigated at a roadside and at a residential area in Osaka, Japan. The direct-acting mutagenicity was evaluated as mutagenic activity per unit volume of ambient air (rev m−3) and/or that per airborne particulate weight collected on a filter (rev mg−1). The annual or diurnal changes of the mutagenicity of airborne particles at the residential site showed similar patterns to those of some gaseous pollutants such as NO2 and SO2, which were emitted from combustion processes. This result indicates that the mutagenicity is mainly attributable to the primary emissions. From the analysis of the relationship between the wind sector and the mutagenic intensity, rev m−3 and rev mg−1 values were strongly affected by the emissions from the fixed sources and from the mobile sources, respectively. The rev m−3 value and concentration of 1-nitropyrene (1-NP) in unit per m3 at the roadside were a factor of 2.6 and 2.8 higher than those at the residential site, respectively, but the rev mg−1 value and concentration of 1-NP in unit per mg at the roadside were substantially comparable to those at the residential area. These observations suggest that the characteristics of the airborne particles can be attributed to the automotive emissions even at the suburban area.  相似文献   
64.
The Llobregat basin is a Mediterranean fluvial system with major agricultural, urban and industrial impacts. We combined chemical quantification by liquid chromatography–mass spectrometry with electrospray interface (LC-ESI-MS) and the recombinant yeast assay (RYA) assays to estimate the loads of endocrine disrupting compounds (EDCs) along the basin. Chemical analysis revealed maximum concentrations (at μg l−1 level) of alkylphenols at the lower course of the Llobregat River, which correlated with high levels of estrogenic activity detected by RYA. Analysis by RYA and LC-ESI-MS of influent and effluent waters from four sewage treatment plants (STP) discharging into the basin showed the removal of 80–95% of EDCs by STP treatment. Chemical analysis data and RYA data showed a quasi-linear correlation, demonstrating the complementariness of both methods. Our data suggest that the concentrations of the analysed compounds were enough to explain the total estrogenicity of water and STP samples from the Llobregat basin.  相似文献   
65.
Two biological aerated filters (BAF) were setup for ammonia removal treatment of the circulation water in a marine aquaculture. One of the BAFs was bioaugmented with a heterotrophic nitrifying bacterium, Lutimonas sp. H10, where the ammonia removal was not improved and the massive inoculation was even followed by a nitrification breakdown from day 9 to 18. The nitrification was remained stable in control BAF operated under the same conditions. Fluorescent in situ hybridization (FISH) with rRNA-targeted probes and cultivable method revealed that Lutimonas sp. H10 almost disappeared from the bioaugomented BAF within 3 d, and this was mainly due to the infection of a specific phage as revealed by flask experiment, plaque assay and transmission electron observation. Analyses of 16S rRNA gene libraries showed that bacterial groups from two reactors evolved di erently and an overgrowth of protozoa was observed in the bioaugmented BAF. Therefore, phage infection and poor biofilm forming ability of the inoculated strain are the main reasons for bioaugmentation failure. In addition, grazing by protozoa of the bacteria might be the reason for the nitrification breakdown in bioaugmented BAF during day 9–18.  相似文献   
66.
Microcystins (MCs) produced by cyanobacteria are strong hepatotoxins and classified as possible carcinogens.MCs pose a considerable threat to human health through tainted drinking and surface waters.Herein filtrated water from a waterworks in Harbin,China,was spiked with microcystin-LR (MC-LR) extracted from a toxic scum of microcystis aeruginosa,and the spiked sample waters were treated using UV irradiation with consequent ozonation process (UV/O3),compared with ozonation at a dose range commonly applied in water treatment plants,UV irradiation at 254 nm and UV irradiation combined with ozonation (UV+O3),respectively.The remaining of toxins were analyzed using high-performance liquid chromatography and also determined using a protein phosphatase type 2A inhibition assay,which was utilized to evaluate the reduction in toxicity.Results indicated that in comparison to other three processes (O3,UV,and UV+O3),UV/O 3 process could effectively decrease both the concentration and toxicity of MC-LR at 100 μg/L level after 5 min UV irradiation with consequent 5 min ozonation at 0.2 mg/L (below 1 μg/L),while 0.5 mg/L ozone dose was required for the level below 0.1 μg/L.The addition of an UV treatment step to the existing treatment train may induce significant transformation of micropollutants and breaks down the natural organic matters into moieties unfavorable for ozone decomposition,stabilizing the ozone residual.These findings suggested that sequential use of UV and ozone may be a suitable method for the removal of these potentially hazardous microcystins from drinking water.  相似文献   
67.
A reliable and sensitive competitive real-time fluorescent quantitative immuno-PCR (RTFQ-IPCR) assay using a molecular beacon was developed for the determination of trace fluoranthene (FL) in the environment. Under optimized assay conditions, FL can be determined in the concentration range from 1 fg/mL to 100 ng/mL, with y = 0.194x + 7.859, and a correlation coe cient of 0.967 was identified, with a detection limit of 0.6 fg/mL. Environmental water samples were successfully analyzed, recovery was between 90% and 116%, with intra-day relative standard deviation (RSD) of 6.7%–12.8% and inter-day RSD of 8.4%–15.2%. The results obtained from RTFQ-IPCR were confirmed by ELISA, showing good accuracy and suitability to analyze FL in field samples. As a highly sensitive method, the molecular beacon-based RTFQ-IPCR is acceptable and promising for providing reliable test results to make environmental decisions.  相似文献   
68.
宋佳秀  任南琪  陈瑛  安东 《环境科学》2009,30(7):2124-2129
将CSTR系统内pH由4.2一次性提高至6.0左右,启动发酵类型的转化,研究了转化过程系统内的产氢动态和细菌群落.结果表明,在有机负荷维持在(33±1)kg/(m3·d)的情况下,发酵类型10 d内未发生改变,产氢量8 d内未降低,15 d后系统内种群由乙醇型转化为丁酸型,进水碱度由250 mg/L增至2 450 mg/L.研究中利用荧光原位杂交技术(FISH)对反应系统内3类微生物群进行监测发现,在转化过程中Clostridium cluster XI数量增加,Clostridium cluster Ⅰ 和Ⅱ数量减少,而Enterobacteriaceae始终存在,变化不明显.种群的消长同反应系统产氢能力的高低存在密切关联,以Clostridium cluster Ⅰ和Ⅱ占优势的乙醇型发酵具有更佳的产氢能力,平均比产氢速率为23.6 mol/(kg·d).  相似文献   
69.
细菌在环境污染物毒性检测中的应用   总被引:2,自引:0,他引:2  
介绍了一些利用细菌作为指示生物监测化学物质毒性的方法,诸如:细菌生化毒理学方法,细菌生长,呼吸抑制实验,细胞发光微毒测定,微热测量以及致突变物检测技术等。  相似文献   
70.
型煤燃烧固硫中的温度效应   总被引:6,自引:0,他引:6  
以氧化钙作为固硫剂的型煤中适当加入Fe,Si添加剂组分,燃烧生成新的固硫体系后进行了2种不同温度条件下的进样实验。1.型煤样品分成6份,进行逐渐升温实验,分别加热到1170℃-1220℃,温度间隔10℃,恒温1/4h,2.型煤样品分成7份,进行先升温后进样实验,将加热炉分别升温至要求温度1000℃-1220℃+后进样,温度间隔50℃,恒温1/2h,实验表明:在Fe,Si体系的型煤燃烧过程中,当进样  相似文献   
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