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741.
以牛粪为发酵原料,研究了不同浓度的Fe2+和Co2+对沼气产量和产气周期的影响。结果表明,物料添加Fe2+和Co2+的浓度为1.2μg/L时均可达到沼气最大产量。物料中Fe2+的浓度为1.2μg/L时,沼气总产量为3 648.25 mL,最高产气可持续7 d,日平均产气量为148 mL;1.2μg/L的Co2+的沼气总产量为2 766.25 mL,最高产气可持续5 d,日平均产气量为132.8 mL。物料添加不同浓度Fe2+和Co2+可延长产气周期,但对沼气生产的启动时间、发酵前后物料的碳氮比及pH值均无影响。 相似文献
742.
743.
采用格栅一旋转固液分离一高效浅层气浮一消解酸化一生化曝气工艺处理高浓度酱厂废水,设计规模为1000 m['3]/h,总排口水质为:pH=7.05、COD<,cr>=71.6mg/L、SS=38mg/L、NH<,3>一N=1mg/L. 相似文献
744.
激光雷达是大气边界层气溶胶和云的一个高效探测工具。2010年12月利用Mie散射激光雷达对广州城区冬季大气边界层进行系统观测,分析讨论了测站地域上空大气气溶胶的消光系数垂直分布和时间变化的主要特征。结果表明:冬季广州大气边界层气溶胶主要分布在1100m以下区域,气溶胶分布具有多层结构;大气边界层高度稳定分布在500~620m左右,边界层高度日变化不明显;冬季广州气溶胶源较为稳定并且变化慢;广州城区气溶胶浓度白天比晚上大,峰值出现11颐00~14颐00左右,谷值出现在20颐00左右。 相似文献
745.
Wenjuan Zhang Wei Liu Jing Zhang Huimin Zhao Yaobin Zhang Xie Quan Yihe Jin 《环境科学学报(英文版)》2012,24(11):2019-2027
Textile industries are important sources of toxic discharges and contribute enormously to water deterioration, while little attention has been paid to the toxicity of textile effluents in discharge regulation. Bioassays with zebrafish were employed to evaluate the toxicity of wastewater samples collected from different stages at a textile factory and sewage treatment plants (STPs). Physico-chemical parameters, acute toxicity, genotoxicity and oxidative stress biomarkers were analyzed. The wastewater samples from bleaching, rinsing and soaping of the textile factory exhibited high acute toxicity and genotoxicity. The coexisting components of dye compounds, as assistants and oxidants, seemed to cause some effect on the toxic response. After treatment employing the anoxic-oxic (A/O) process in STPs, the color and the chemical oxygen demand (COD) were reduced by 40% and 84%, respectively, falling within the criteria of the Chinese Sewage Discharge Standard. In contrast, increases in acute toxicity and genotoxicity were observed in the anaerobic tank, indicating the formation of toxic intermediates. The genotoxicity of the effluent of the STP was not significantly different from that of the influent, suggesting the wastewater treatment processes were not effective in removing the genotoxicity of the dye wastewater. Results indicated that the effluent contains pro-oxidants since the activities of glutathione (GSH), malondialdehyde (MDA), and total anti-oxidation capacity (T-AOC) were all elevated. In addition, decreases in superoxide dismutase (SOD) and glutathione-S transferase (GST) activities observed can be interpreted as a cytotoxicity sign due to an over-production of reactive oxygen species (ROS). The results of the present study suggest that the STPs were not capable of reducing the toxicity of wastewater sufficiently. Further treatment is needed to remove the potential risks posed by textile effluent to ecosystems and human health, and employing a toxicity index is necessary for discharge regulation. 相似文献
746.
747.
Wenjun Xie Aiping Chen Jianyong Li Qing Liu Hongjun Yang Tao Wu Zhaohua Lu 《环境科学学报(英文版)》2012,24(9):1655-1661
The Yellow River Delta (YRD) is a typical agricultural and petrochemical industrial area of China. To assess the current status of soil dichlorodiphenyltrichloroethane (DDT) and polychlorinated biphenyls (PCB) residues, topsoil samples (0-15 cm) (n = 82) were collected in Bincheng District, at the geographic center of the YRD. The total concentrations of six DDT homologues were within 3.3-3819 μg/kg, with a mean concentration of 191 μg/kg, showing significant increase along urban-rural gradient. Soil concentrations of seven indicator PCBs in the area ranged from non-detectable to 87.0 μg/kg, dominated by heavily chlorinated PCBs (PCB-101 and -118). Soil PCBs concentrations were significantly greater in urban than suburban and rural areas. Principal component and multiple linear regression analysis suggest that 86.4% of soil DDTs originate from past DDT usage, and 13.6% originate from dicofol application. Soil PCBs most likely originate from the petrochemical industry (77.1%), municipal solid waste disposal (16.5%), local commercial PCB homologues usage (5.2%), and long-range atmospheric deposition (1.2%). In general, soil DDTs pollution was classified as low level, and mean PCBs concentrations were below the severe contamination classification range. Because PCB-118 is a dioxin-like congener, monitoring and remediation is advised to assess and reduce negative environmental and human health effects from soil DDTs and dioxin-like congeners in the study area. 相似文献
748.
谢健 《安全.健康和环境》2012,12(2):45-46
针对油气管道企业的实际生产运营特点,对风险管理的基本思路进行了探讨,就目前国内外常用危害因素的识别评判方法进行了归纳分析,给出了适合输油站队的风险控制的管理方法和措施。 相似文献
749.
750.
石兜—坂头水库是厦门市的重要饮用水水源地,其水质的好坏直接影响供水安全保障。根据2007年11月-2011年10月的水质监测数据,参照GB 3838-2002Ⅱ类水质标准,将27项水质监测指标分为3类,计算历年丰、平、枯水期水质综合指数(WQI),评价水质状况。结果表明:①难处理的毒性污染指标的WQI值小于10,远未危及水质安全;②易净化的污染指标中高锰酸盐指数、五日生化需氧量、大肠杆菌等在个别时段超标;③影响水质的最主要指标是总磷和总氮,单项指数常年保持在40以上,并曾一度接近80,达到Ⅳ类水质标准,水体受到一定的氮、磷污染。④4年来,水质变化处于相对比较稳定的状态,丰、平、枯水期水质变化不甚明显,最大WQI为33.3,水质评价为优良,是合格的供水水源地。就污染物成因及该水源地保护措施进行了探讨。 相似文献