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111.
Widespread use of phenols has led to ubiquitous exposure to phenols. In experimental animals, phenols increased resorptions, reduced live litter size and fetal body weights. However, there are limited epidemiological evidences of the relationships between exposure to phenols and pregnancy outcomes. We evaluated the associations between parental urinary levels of various phenols and spontaneous abortion in a Chinese population residing in the middle and lower reaches of the Yangtze River. A case-control study was conducted that included 70 case couples with medically unexplained spontaneous abortion and 180 control couples who did not have a history of spontaneous abortion and had at least one living child. Both parental urinary phenols were measured by ultra-high performance liquid chromatography-tandem mass spectrometry including bisphenol A (BPA), benzophenone-3 (BP-3), 2,3,4-trichlorophenol (2,3,4-TCP), pentachlorophenol (PCP), 4-n-octylphenol (4-n-OP) and 4-n-nonylphenol (4-n-NP). Compared with the low exposure group, there was an increased risk of spontaneous abortion with high paternal urinary PCP concentration [odds ratio (OR) = 2.09, 95% Confidence Interval (CI), 1.05–4.14], and maternal exposure to 4-n-OP and alkylphenol(s) also significantly increased the risk of spontaneous abortion (OR = 2.21, 95% CI, 1.02–4.80; OR = 2.81, 95% CI, 1.39–5.65, respectively). Our study firstly provides the evidence that paternal PCP exposure, maternal 4-n-OP and alkylphenol(s) exposure are associated with spontaneous abortion in humans.  相似文献   
112.
Trichosporon mycotoxinivorans XPY-10是一株分离自抗生素制药厂的高效四环素降解酵母菌。为了建立该菌株降解四环素的适宜条件,分别研究了碳源、有机氮源、金属离子等营养物质及初始底物浓度、接种量、pH、温度、装液量、摇床转速等理化因素对菌体生长及四环素降解效率的影响。结果表明,菌株XPY-10生长的最适碳源和氮源分别为蔗糖和蛋白胨。在含有0.05%FeSO4的培养基中,菌株XPY—10降解四环素的适宜条件为:接种量2%,pH8,温度3422,装液量100mL(250mL三角瓶),摇床转速180r/min。在此条件下,菌株XPY—10在7d内对初始浓度为600mg/L的四环素降解率为83.63%。本菌株对养殖废水及制药废水中四环素的污染治理有一定的应用前景。  相似文献   
113.
Environmental Science and Pollution Research - Aerobic denitrifiers have the potential to reduce nitrate in polluted water under aerobic conditions. A salt-tolerant aerobic denitrifier was newly...  相似文献   
114.
Ammonia (NH3) removal efficencies were evaluated when hydrogen sulfide (H2S) and NH3 in binary mixture gases were supplied to a ceramic biofilter seeded with earthworm (Lumbricus terrestris) casts. The effect of inlet H2S concentration and space velocity (SV) on the removal of NH3 was investigated after the acclimation of the biofilter with NH3 gas. When NH3 was singly supplied to the biofilter, NH3 removal was maintained at almost 100% until inlet NH3 concentration was increased up to 600 microL L(-1) and SV up to 330 h(-1), at which the elimination capacity of NH3 was 148 g N m(-3) h(-1). When H2S was supplied simultaneously, however, the accumulation of toxic sulfide ions showed dual effects on NH3 removal efficiencies. First, no effects were observed at inlet H2S loading below 60 g S m(-3) h(-1); however, inhibition by H2S at higher loading was observed above 60 g S m(-3) h(-1). The point at which loading achieved a maximum of more than 99% NH3 removal efficiency was 139 g N m(-3) h(-1), when inlet H2S concentration was held under 100 microL L(-1), but it dropped to 76 and 30 g N m(-3) h(-1) when the inlet H2S concentration increased to 220 and 460 microL L(-1), respectively. The critical points of inlet H2S loading that guaranteed over 99% NH3 removal were determined as 100, 100, 60, and 40 g S m(-3) h(-1) at inlet NH3 concentrations of 100, 200, 400, and 600 microL L(-1), respectively. Inlet NH3 loading had synergic effects of increasing the inhibition of inlet H2S loading on the NH3 removability of the biofilter.  相似文献   
115.
● NH3 in biogas had a slight inhibitory effect on dry reforming. ● Coexistence of H2S and NH3 led to faster decline of biogas conversion. ● Regeneration was effective for catalysts deactivated under synergetic effect. Biogas is a renewable biomass energy source mainly composed of CH4 and CO2. Dry reforming is a promising technology for the high-value utilization of biogas. Some impurity gases in biogas can not be completely removed after pretreatment, which may affect the performance of dry reforming. In this study, the influence of typical impurities H2S and NH3 on dry reforming was studied using Ni/MgO catalyst. The results showed that low concentration of H2S in biogas could cause serious deactivation of catalyst. Characterization results including EDS, XPS and TOF-SIMS confirmed the adsorption of sulfur on the catalyst surface, which was the cause of catalyst poisoning. We used air calcination method to regenerate the sulfur-poisoned catalysts and found that the regeneration temperature higher than 500 °C could help catalyst recover the original activity. NH3 in the concentration range of 50–10000 ppm showed a slight inhibitory effect on biogas dry reforming. The decline rate of biogas conversion efficiency increased with the increase of NH3 concentration. This was related to the reduction of oxygen activity on catalyst surface caused by NH3. The synergetic effect of H2S and NH3 in biogas was investigated. The results showed that biogas conversion decreased faster under the coexistence of H2S and NH3 than under the effect of H2S alone, so as the surface oxygen activity of catalyst. Air calcination regeneration could also recover the activity of the deactivated catalyst under the synergetic effect of H2S and NH3.  相似文献   
116.
对某市区重点行业15家企业职业病危害因素进行检测与评价,对普查结果进行综合分析。结果表明:15家企业工作场所化学有害因素职业卫生现状情况良好,但噪声危害程度较大;在6个重点行业中,电子制造行业有害因素合格率最低,为84%,其次是纺织行业,有害因素合格率为85%,其他化学原料及化学制品、化工、木制家具、石材加工四个行业合格率均较高;市直以上企业职业卫生现状情况优于区属企业,300-2000人之间较大规模的企业职业卫生现状情况优于300人以下的企业。同时,对企业提出了职业危害现状的改进措施与建议。  相似文献   
117.
本文采用2007年大连市环境自动监测数据,分析了城市中心区O3的污染特征。结果表明:O3质量浓度的最大值出现在午后15:00—17:00,比太阳辐射强度最大值的出现时间滞后2h左右;O3质量浓度的季节性变化十分显著,春夏季较高,秋季次之,冬季最低;汽车尾气是近地面O3污染的主要原因。  相似文献   
118.
为了提高油田采油(气)污水处理能力,胜利油田开发研制出新型絮凝浮选剂PS-01,以聚合铝为主,配以常用的助凝剂二氧化硅气溶胶,工业用硫酸镁等,按比例混合在一起配置而成。在试验中将它们与油田内广泛使用的絮凝浮选剂SG-01,JX-01,NA-1等进行比较。结果表明:PS-01絮凝浮选剂的原料来源广泛,合成工艺简单,易于操作;对采油(气)污水处理效果好,加药量少,处理成本低;应用的pH范围较宽,反应迅速,可缩短混合反应时间;适用性强,低温时效果不受影响;对投药设备的腐蚀性小,性质稳定,无沉淀产生;同时各种原料的不同配比对絮凝浮选效果影响很大,要控制好比例。  相似文献   
119.
环境行政强制包括环境行政强制措施和环境行政强制执行.在基层环境执法实践中,环境行政强制措施尤其是环境行政强制执行存在许多困惑和问题,拓展环境行政强制措施,给予环保部门一定的行政强制执行权是提高基层环境执法效率和遏制环境污染的有效途径.  相似文献   
120.
城市地下空间是城市空间资源的重要组成部分,在提高土地利用效率、缓解城市矛盾、节约能源、保护环境等方面起着举足轻重的作用,其开发利用与规划工作已被国家列入城市规划的重要内容。回顾国内地下空间开发方面的研究,可以概括为解决了开发情况介绍、开发效益分析、内部环境研究、利用规划管理4类,只要我们解决了研究存在的一些问题,就可更好推动我国地下空间建设健康协调发展。  相似文献   
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