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941.
从实现新时期统筹发展的国家战略需求出发,剖析了大都市群跨区域交叉污染、复合污染、累计污染的特点,指出这些区域已成为环境资源“漏斗区”和突发性环境危机的风险区。认为只有采取主动引导发展的国家环境战略才能有效地解决大都市群和环境的协调可持续发展问题。阐述了主动环保战略的重大措施包括引导调整发展布局、转变经济增长方式、转变生活方式、创新国家环境管理体制、创新环境科技体系和系统、人工提高环境承载能力等。 相似文献
942.
The effects of water flow rate and antifouling agents on the extent of biofouling and on the uptake of non-polar organic contaminants by semipermeable membrane devices (SPMDs) were studied during four field experiments in the Western Wadden Sea. Biofouling densities on the sampler surface ranged from 0.3 to 16 g dry weight dm−2. Water sampling rates were estimated from the dissipation rates of performance reference compounds (PRCs). The antifouling agents Irgarol and capsaicin (33 mg per ml triolein) had no noticeable effect on the extent of fouling, and caused only a 5–10% increase in the absorbed amounts. Enhanced flow rates had only a minimal effect on the amount of biofouling, but caused the water sampling rates to increase by a factor of 1.2–2. Increases in PRC-derived sampling rates were reflected by increases in the absorbed amounts for compounds that were in the linear uptake stage of the sampling process. The results imply (1) that extreme biofouling does not always result in reduced sampling rates, (2) that extreme biofouling does not preclude the existence of flow effects on the sampling rates, and (3) that differences in uptake rates are quantitatively reflected by the dissipation rates of PRCs. 相似文献
943.
Rastall AC Getting D Goddard J Roberts DR Erdinger L 《Environmental science and pollution research international》2006,13(4):256-267
Goal, Scope and Background
Some anthropogenic pollutants posses the capacity to disrupt endogenous control of developmental and reproductive processes
in aquatic biota by activating estrogen receptors. Many anthropogenic estrogen receptor agonists (ERAs) are hydrophobic and
will therefore readily partition into the abiotic organic carbon phases present in natural waters. This partitioning process
effectively reduces the proportion of ERAs readily available for bioconcentration by aquatic biota. Results from some studies
have suggested that for many aquatic species, bioconcentration of the freely-dissolved fraction may be the principal route
of uptake for hydrophobic pollutants with logarithm n-octanol/water partition coefficient (log Kow) values less than approximately
6.0, which includes the majority of known anthropogenic ERAs. The detection and identification of freely-dissolved readily
bioconcentratable ERAs is therefore an important aspect of exposure and risk assessment. However, most studies use conventional
techniques to sample total ERA concentrations and in doing so frequently fail to account for bioconcentration of the freely-dissolved
fraction. The aim of the current study was to couple the biomimetic sampling properties of semipermeable membrane devices
(SPMDs) to a bioassay-directed chemical analysis (BDCA) scheme for the detection and identification of readily bioconcentratable
ERAs in surface waters.
Methods
SPMDs were constructed and deployed at a number of sites in Germany and the UK. Following the dialytic recovery of target
compounds and size exclusion chromatographic clean-up, SPMD samples were fractionated using a reverse-phase HPLC method calibrated
to provide an estimation of target analyte log Kow. A portion of each HPLC fraction was then subjected to the yeast estrogen
screen (YES) to determine estrogenic potential. Results were plotted in the form of 'estrograms' which displayed profiles
of estrogenic potential as a function of HPLC retention time (i.e. hydrophobicity) for each of the samples. Where significant
activity was elicited in the YES, the remaining portion of the respective active fraction was subjected to GC-MS analysis
in an attempt to identify the ERAs present.
Results and Discussion
Estrograms from each of the field samples showed that readily bioconcentratable ERAs were present at each of the sampling
sites. Estimated log Kow values for the various active fractions ranged from 1.92 to 8.63. For some samples, estrogenic potential
was associated with a relatively narrow range of log Kow values whilst in others estrogenic potential was more widely distributed
across the respective estrograms. ERAs identified in active fractions included some benzophenones, various nonylphenol isomers,
benzyl butyl phthalate, dehydroabietic acid, sitosterol, 3-(4-methylbenzylidine)camphor (4-MBC) and 6-acetyl-1,1,2,4,4,7-hexamethyltetralin
(AHTN). Other tentatively identified compounds which may have contributed to the observed YES activity included various polycyclic
aromatic hydrocarbons (PAHs) and their alkylated derivatives, methylated benzylphenols, various alkylphenols and dialkylphenols.
However, potential ERAs present in some active fractions remain unidentified.
Conclusions and Outlook
Our results show that SPMD-YES-based BDCA can be used to detect and identify readily bioconcentratable ERAs in surface waters.
As such, this biomimetic approach can be employed as an alternative to conventional methodologies to provide investigators
with a more environmentally relevant insight into the distribution and identity of ERAs in surface waters. The use of alternative
bioassays also has the potential to expand SPMD-based BDCA to include a wide range of toxicological endpoints. Improvements
to the analytical methodology used to identify ERAs or other target compounds in active fractions in the current study could
greatly enhance the applicability of the methodology to risk assessment and monitoring programmes. 相似文献
944.
Ohmichi K Komiyama M Matsuno Y Takanashi Y Miyamoto H Kadota T Maekawa M Toyama Y Tatsugi Y Kohno T Ohmichi M Mori C 《Environmental science and pollution research international》2006,13(2):120-124
Goal, Scope and Background Cadavers for gross anatomy laboratories are usually prepared by using embalming fluid which contains formaldehyde (FA) as
a principal component. During the process of dissection, FA vapors are emitted from the cadavers, resulting in the exposure
of medical students and their instructors to elevated levels of FA in the laboratory. The American Conference of Governmental
Industrial Hygienists (ACGIH) has set a ceiling limit for FA at 0.3 ppm. In Japan, the Ministry of Health, Labour and Welfare
has set an air quality guideline defining two limit values for environmental exposure to FA: 0.08 ppm as an average for general
workplaces and 0.25 ppm for specific workplaces such as an FA factory. Although there are many reports on indoor FA concentrations
in gross anatomy laboratories, only a few reports have described personal FA exposure levels. The purpose of the present study
was to clarify personal exposure levels as well as indoor FA concentrations in our laboratory in order to investigate the
relationship between them.
Methods The gross anatomy laboratory was evaluated in the 4th, 10th and 18th sessions of 20 laboratory sessions in total over a period
of 10 weeks. Air samples were collected using a diffusive sampling device for organic carbonyl compounds. Area samples were
taken in the center and four corners of the laboratory during the entire time of each session (4-6 hours). Personal samples
were collected from instructors and students using a sampling device pinned on each person's lapel, and they were 1.1 to 6
hours in duration. Analysis was carried out using high performance liquid chromatography.
Results and Discussion Room averages of FA concentrations were 0.45, 0.38 and 0.68 ppm for the 4th, 10th and 18th sessions, respectively, ranging
from 0.23 to 1.03 ppm. These levels were comparable to or relatively lower than the levels reported previously, but were still
higher than the guideline limit for specific workplaces in Japan and the ACGIH ceiling limit. The indoor FA concentrations
varied depending on the contents of laboratory sessions and seemed to increase when body cavity or deep structures were being
dissected. In all sessions but the 4th, FA levels at the center of the room were higher than those in the corners. This might
be related to the arrangement of air supply diffusers and return grills. However, it cannot be ruled out that FA levels in
the corners were lowered by leakage of FA through the doors and windows. Average personal exposure levels were 0.80, 0.45
and 0.51 ppm for instructors and 1.02, 1.08 and 0.89 ppm for students for the 4th, 10th and 18th session, respectively. The
exposure levels of students were significantly higher than the mean indoor FA concentrations in the 4th and 10th sessions,
and the same tendency was also observed in the 18th session. The personal exposure level of instructors was also significantly
higher than the indoor FA level in the 4th session, while they were almost the same in the 10th and 18th sessions. Differences
in behavior during the sessions might reflect the differential personal exposure levels between students and instructors.
Conclusion The present study revealed that, if a person is close to the cadavers during the gross anatomy laboratory, his/her personal
exposure level is possibly 2 to 3-fold higher than the mean indoor FA concentration. This should be considered in the risk
assessment of FA in gross anatomy laboratories.
Recommendation and Outlook If the risk of FA in gross anatomy laboratories is assessed based on the indoor FA levels, the possibility that personal
exposure levels are 2 to 3-fold higher than the mean indoor FA level should be taken into account. Otherwise, the risk should
be assessed based on the personal exposure levels. However, it is hard to measure everyone's exposure level. Therefore, further
studies are necessary to develop a method of personal exposure assessment from the indoor FA concentration. 相似文献
945.
SBR法降解处理日化厂废水的实验研究 总被引:2,自引:1,他引:1
日化厂废水成分复杂,其中表面活性剂、含P化合物、油脂、色素等严重污染生态环镜,较难处理.本文采用小规模的间歇式活性污泥法(SBR)生物反应器降解处理日化厂废水,分析了废水降解过程中污泥体积指数、污泥负荷、容积负荷等微生物学的特性变化,并讨论了曝气时间、污泥负荷、容积负荷对污染物去除率的影响.结果表明,通过对普通活性污泥的培养与驯化,利用SBR工艺降解处理日化厂废水是可行的.当曝气时间为4.5 h,污泥负荷为1.2 kg/(kg·d)(以MLSS计的COD),容积负荷为2.1~2.3g/(L·d)时,COD、油脂、总磷、表面活性剂(SAA)、SO42-等的去除率分别可达92.3%,99.1%,99.3%,99.3%,99.0%和98.9%. 相似文献
946.
947.
研究了溶胶-凝胶法制备以活性炭为载体的TiO2膜。通过实验确定了溶胶一凝胶体系的最佳组成,对涂膜的次数、煅烧温度、保温时间等因素进行实验,确定了涂膜的最佳工艺,并用于处理有机染料污水,脱色率达92%。 相似文献
948.
中美校车安全标准比较研究 总被引:1,自引:0,他引:1
为促进我国校车安全标准法规的发展,提高我国校车的安全技术水平,选择美国校车安全标准作为我国校车安全标准比较研究的对象,分别从校车的一般安全、主动安全和被动安全技术条件方面,将我国现已实施的校车安全标准和美国的校车安全标准进行比较。研究结果表明,我国校车安全标准和美国的校车安全标准之间存在一定差异,在应急出口、碰撞试验等方面还存在不足。根据研究结果,提出有关制定适合中国国情的校车安全标准和法规的建议。 相似文献
949.
Luo J.Wang H.Chen L. 《应用与环境生物学报》2018,(4):934-940
Subway systems are indispensable for transportation in modern cities, with the air being easily polluted by microbes owing to the enclosed and crowded environment. The microbiological characteristics of subway aerosols have attracted the attention of researchers worldwide during recent years. This review aimed to evaluate the sampling and analyzing methods suitable for detecting airborne microbes in subway systems. Active air sampling methods and molecular biology techniques based on polymerase chain reaction (PCR) such as 16S rRNA gene sequencing, metagenomics, and quantitative PCR demonstrated great potential in microbial analysis of aerosols because they can provide accurate and comprehensive information. Temporal and spatial distributions of airborne microbes, as well as the factors influencing their distribution characteristics, were also discussed by critically reviewing worldwide literature on subway microbiome studies. The concentration and composition of airborne bacteria and fungi in subway can vary dramatically with time and space. The critical factors determining microbial community structure and composition include temperature, relative humidity, carbon dioxide concentration, number of passengers, presence of platform screen door, ventilation systems, and so on. The review suggests that future studies on standardized sampling and analyzing protocols are required to obtain contamination levels of subway airborne microbes and to establish the relationship between microbial monitoring data and public health risks. © 2018 Science Press. All rights reserved. 相似文献
950.
PAC-SBR法处理制药废水污泥驯化研究 总被引:3,自引:0,他引:3
制药废水的特点是成分复杂,有机物浓度高,且含有难生物降解和有抑制作用的抗生素等毒性物质,较为适合的处理方法是生化处理。研究了PAC-SBR反应器处理盐酸林可霉素原料药生产废水过程中活性污泥的驯化。活性污泥经1个月3阶段的驯化后,已基本适应盐酸林可霉素原料药生产废水特性,活性污泥驯化完成。 相似文献