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621.
大气颗粒物化学质量平衡源解析方法研究   总被引:3,自引:0,他引:3  
对基于化学质量平衡原理(CMB)的大气颗粒物来源解析方法中各步骤的研究情况进行综述。重点对土壤尘、煤烟尘、尾气尘、道路尘、城市扬尘、建筑水泥尘、海盐粒子等污染源样品采集方法,环境空气中颗粒物样品采集用滤膜及采样器,样品中各组分分析方法,以及采用cMB模型进行源解析拟合计算软件的发展情况进行了介绍,同时针对目前源解析中存在的问题提出了一些建议。  相似文献   
622.
为了提高传统sBR脱氮除磷效率,采用泥膜复合sBR工艺处理人工模拟生活污水,通过小试试验探讨了不同泥龄系统脱氮除磷能力的影响。结果表明:系统不仅对TN、TP表现出稳定良好的去除效率,出水TN、TP浓度符合《城镇污水处理厂污染物排放标准》(GB18918—2002)的一级A标准;而且提高了系统抗冲击负荷能力。  相似文献   
623.
以无锡市滨湖区工矿废弃地复垦用地为例,研究土地废弃地复垦下土壤质量情况.通过对土壤总氮(TN)、总磷(TP)、重金属等指标的监测分析.得出如下结论:(1)监测样点土壤pH处于中性或偏碱性,土壤保肥能力明显不足,工矿复垦用地土壤pH与土壤阳离子交换量(CEC)呈较为显著的线性负相关.(2)工矿废弃地复垦用地土壤TN、TP在较低水平,与土地用地类型有关.复垦为园林用地的样点土壤TN、TP含量高于复垦为耕地的样点.土壤TN含量与土壤质地有关,与土壤CEC呈一定程度的平行关系.(3)局部重金属含量超出土壤环境质量标准(GBl5618-1995)一级保护区的标准,Ni污染最高,其次为Zn.复垦为园林用地对土壤质量有较大的改善.表明开展研究区域的土地生态修复相当必要,工矿废弃地宜先复垦为园林用地,再结合实际改造为目标用地.在无锡太湖保护区,应该以蓝藻的充分利用和现有的植物修复方法为手段,进行土地生态修复的进一步研究.  相似文献   
624.
介绍了气体检测报警器中催化燃烧式、红外式、电化学式、光电离式传感器的工作原理,提出了不同气体检测报警器使用中的注意事项。  相似文献   
625.
Membrane fouling limits the effects of long-term stable operation of membrane bioreactor (MBR). Control of membrane fouling can extend the membrane life and reduce water treatment cost effectively. A pilot scale anoxic/aerobic-membrane bioreactor (A/O-MBR, 40 L/hr) was used to treat the hyperhaline municipal sewage from a processing zone of Tianjin, China. Impact factors including mixed liquid sludge suspension (MLSS), sludge viscosity (μup), microorganisms, extracellular polymeric substances (EPS), aeration intensity and suction/suspended time on membrane fouling and pollution control were studied. The relationships among various factors associated with membrane fouling were analyzed. Results showed that there was a positive correlation among MLSS, sludge viscosity and trans-membrane pressure (TMP). Considering water treatment efficiency and stable operation of the membrane module, MLSS of 5 g/L was suggested for the process. There was a same trend among EPS, sludge viscosity and TMP. Numbers and species of microorganisms affected membrane fouling. Either too high or too low aeration intensity was not conducive to membrane fouling control. Aeration intensity of 1.0 m3/hr (gas/water ratio of 25:1) is suggested for the process. A long suction time caused a rapid increase in membrane resistance. However, long suspended time cannot prevent the increase of membrane resistance effectively even though a suspended time was necessary for scale off particles from the membrane surface. The suction/suspended time of 12 min/3 min was selected for the process. The interaction of various environmental factors and operation conditions must be considered synthetically.  相似文献   
626.
The effects of different mixing ratios of methanol/gasoline blends and new three-way catalytic converter on regulated and unregulated emissions, especially VOC and carbonyl compound emissions were investigated.  相似文献   
627.
Concerns about the carcinogenic and endocrine-disrupting characteristics of organochlorine pesticides (OCPs) have led to a global ban on OCP use. However, OCPs persist in the environment for decades because of their long half-life. We evaluated serum levels of OCPs and their correlations with usual dietary intake and other lifestyle factors among 250 healthy women who participated as controls in the Shanghai Breast Cancer Study. Serum levels of hexachlorocyclohexane isomers (alpha-HCH, beta-HCH, gamma-HCH), dichloro-di-phenyl-trichloroethane (DDT) isomers (p,p'-DDE and p,p'-DDT), hexachlorobenzene (HCB), trans-nonachlor (TNC), and eight polychlorinated biphenyls (PCB) congeners (IUPAC no. 74, 118, 138, 153, 170, 180, 183, and 187) were measured. Lifestyle factors and usual dietary habits over the past 5 years were assessed through an in-person interview. With the exception of PCB, total OCP levels in our study population were significantly higher than those observed in other countries. Age, income, body mass index, waist-to-hip ratio, number of pregnancies, and/or total duration of breastfeeding were all significantly correlated with all types of OCPs. Of the 20 food groups evaluated, correlations with serum total OCPs were observed for eggs (r=0.13), fresh beans (r=-0.17), tea (r=0.14), and animal fat (r=0.18). Multiple regression analyses showed that age and animal fat intake were positively associated with serum total level OCPs, while leafy vegetable and fresh bean consumption was negatively associated with OCPs level. Our study suggests that dietary intake may be an important contributor of serum levels of OCPs in Chinese women.  相似文献   
628.
介绍了吸附法净化燃煤烟气汞的发展趋势,主要包括:活性炭吸附法、活性炭吸附再生法、改性活性炭吸附法、活性炭纤维吸附法以及我们所研究的载银活性炭纤维-低温等离子体原位再生技术等,希望能够为我国汞谈判、汞减排及汞资源的回收利用提供新的思路。  相似文献   
629.
To evaluate contamination caused by petroleum, surface soil samples were collected from both upland and paddy fields along the irrigation canals in the Hunpu wastewater irrigation region in northeast China. N-alkanes, terpanes, steranes, and phospholipid fatty acids (PLFA) in the surface soil samples were analyzed. The aliphatic hydrocarbon concentration was highest in the samples obtained from the upland field near an operational oil well; it was lowest at I-3P where wastewater irrigation promoted the downward movement of hydrocarbons. The Hunpu region was found contaminated by heavy petroleum from oxic lacustrine fresh water or marine deltaic source rocks. Geochemical parameters also indicated significantly heavier contamination and degradation in the upland fields compared with the paddy fields. Principal component analysis based on PLFA showed various microbial communities between petroleum contaminated upland and paddy fields. Gram-negative bacteria indicated by 15:0, 3OH 12:0, and 16:1(9) were significantly higher in the paddy fields, whereas Gram-positive bacteria indicated by i16:0 and 18:1(9)c were significantly higher in the upland fields (p < 0.05). These PLFAs were related to petroleum contamination. Poly-unsaturated PLFA (18:2ωup6, 9; indicative of hydrocarbon-degrading bacteria and fungi) was also significantly elevated in the upland fields. This paper recommends more sensitive indicators of contamination and degradation of petroleum in soil. The results also provide guidelines on soil pollution control and remediation in the Hunpu region and other similar regions.  相似文献   
630.
Industrial safety has noticeably improved in recent years in Taiwan. Despite these improvements, however, serious accidents including explosions, chemical releases, and fires have still occurred in companies such as the Fu Guo Chemical Company (2001), Sin Hun Chemical Company (2005), Motech Industries, Inc. (2005) and Nanpao Resin Co. (2010). These accidents resulted in great loss of life and property, and further caused demands for improvement. Chemical disasters usually result from the combination of several mistakes or gross carelessness and are seldom caused by a single episode. To ensure the safety of operating, handling and storing chemicals, as well as to prevent chemical disasters, one must take many critical points into account, such as techniques, manufacturing processes, operators, chemicals, and emergency response. In Taiwan, the hazards and risks of high-tech companies are higher than in other industrial sectors. Therefore, a variety of safety management methods and regulations appropriate for high-tech companies have been generated. We studied the current status of the indigenous loss prevention protocols based on the safety management of petrochemical and chemical-process high-tech industries in Taiwan.  相似文献   
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