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101.
This study aimed to reveal how amoxicillin(AMX) affected the microbial community and the spread mechanism of antibiotic resistance genes(ARGs) in the AMX manufacture wastewater treatment system. For this purpose, a 1.47 L expanded granular sludge bed(EGSB) reactor was designed and run for 241 days treating artificial AMX manufacture wastewater. 454 pyrosequencing was applied to analyze functional microorganisms in the system. The antibiotic genes OXA_(-1), OXA_(-2), OXA_(-10), TEM_(-1), CTX-M_(-1), class I integrons(intI1) and 16 SrRNA genes were also examined in sludge samples. The results showed that the genera Ignavibacterium, Phocoenobacter,Spirochaeta, Aminobacterium and Cloacibacillus contributed to the degradation of different organic compounds(such as various sugars and amines). And the relative quantification of eachβ-lactam resistance gene in the study was changed with the increasing of AMX concentration.Furthermore the vertical gene transfer was the main driver for the spread of ARGs rather than horizontal transfer pathways in the system. 相似文献
102.
针对传统Fenton体系Fe(Ⅲ)累积和pH适用范围过窄等缺点,采用羟胺(HA)强化的HA-Fenton体系,以对氯苯酚(4-CP)为目标污染物进行降解实验,考察了Fe(Ⅱ)投加量、H2O2投加量、HA投加量和溶液pH等工艺条件对4-CP去除率的影响。实验结果表明:HA-Fenton体系适用于酸性和弱酸性条件,最佳pH范围为3.0~4.0;在溶液pH为3.0、Fe(Ⅱ)投加量为5.0 μmol/L、H2O2投加量为0.4 mmol/L、HA投加量为0.20 mmol/L的最适条件下,反应10 min, 4-CP去除率达64.25 %。 相似文献
103.
湖沼是重要的自然资源,是开发水体生态农业以及发展轻化工业原材料的生产基地保护湖沼资源不但能调控环境,且可成为天然水生或沼生生物基因库。对江汉湖沼资源的合理开发利用,既能收到巨大经济效益,又可保护湖沼生态环境和发挥其生态效益作用。 相似文献
104.
采用垂直流人工湿地模拟装置对新疆油田外排含盐稠油废水进行了处理。实验表明:对于进水CODCr为402~406mg/L,盐度5701~5712mg/L,石油类40.62mg/L的含盐稠油废水,该系统的出水指标为CODCr35~38mg/L,盐度1535~1542mg/L,湿地系统对CODCr和盐分的去除率达到91%和73%;当水力停留时间为11d以上,出水石油类<5mg/L,处理后出水CODCr、石油类达到《污水综合排放标准》(GB8978-1996)的一级标准。 相似文献
105.
本文研究了8种与拟除虫菊酯合成有关的化合物在金鱼和鲤鱼肌肉中的积累和释放行为.实验结果表明,不同鱼种积累同一化合物的程度不同,其差别随着分配系数的增加而显著增加.平衡时的生物富集因子的对数log(BCF)值与分配系数的对数log P值之间有较好的线性关系,其相关方程式为log(BCF)=1.062 logP-1.558(n=8,r=0.975).化合物从鱼体释放到水中的速度符合一级反应动力学公式.释放半衰期的对数log t_(1/2)值亦与log P值相关.其相关方程式为log t_(1/2)=0.784 log P-1.571(n=8,r=0.945).本文结果有助于预测该类有机污染物对环境的影响. 相似文献
106.
107.
The impact of air masses motion on marine aerosol properties was investigated using an on-board single particle mass spectrometer(SPAMS) deployed for the determination of single particle size resolved chemical composition over Southeast China Sea. Two aerosol blooms(E1 and E2) were observed during the cruise. High average particle number count occurred in E1(7320), followed by E2(5850), which was more than 100–150 times of the average particle number count during normal periods. Particles were classified as four major sources, including continental source, shipping source, marine source, and transport source based on the mass spectral similarity. Transport source was identified as those particles with high particle number count occurred only during aerosol bloom period. Three sub-types of EC-Ca, OC-Ca, and Al-rich were classified as transport source.EC-Ca was the dominant particles of the transport source, accounting for more than 70%of the total particles in aerosol bloom events. A uni-modal size distribution in the size range of 0.1–2.0 μm was observed during normal period, while a bimodal distribution with a tiny mode(0.3 μm) and a coarse mode between 0.4 and 0.6 μm was present during aerosol bloom. The variation of aerosol source is consistent with air masses back trajectories, for the reason that most of the long-range air trajectories are from the ocean,while short air trajectories originate in the continental regions, which means that air masses have a significant impact on the aerosol physical–chemical properties along their tracks. 相似文献
108.
为了提高空气质量改善进程,2013 年国家发布了《大气污染防治行动计划》。本文基于空气污染与健康效益评估模型(BenMAP),对人口分布资料、大气污染与人体健康影响的暴露反应关系等进行了本土化修正,采用“支付意愿法”与“疾病成本法”相结合的方法,系统评估了《大气污染防治行动计划》实施后,PM2.5 污染变化引起的环境健康效益。研究结果表明,《大气污染防治行动计划》的实施将在一定程度上降低PM2.5 环境浓度,改善环境空气质量。如果《大气污染防治行动计划》空气质量目标全面实现,可以避免城镇8.9 万居民的过早死亡,减少12 万人次住院治疗以及941 万人次的门诊和急诊病例,实现的全国健康效益约为867 亿元/ 年,说明了《大气污染防治行动计划》实施的健康有益性。本文对政府部门开展污染损失评估及制定环境健康政策具有重要的参考价值。 相似文献
109.
采用臭氧氧化—包埋菌流化床生物处理组合工艺对煤气化废水进行深度处理。实验结果表明:当臭氧的质量浓度20 mg/L、臭氧进气流量1.5 L/min、臭氧通气时间30 min、包埋菌流化床水力停留时间24 h时,臭氧氧化工序的COD去除率达到30.0%~40.0%,总酚去除率达到100.0%;包埋菌流化床工序的COD去除率达到60.0%以上,氨氮的去除率大于95.0%;经组合工艺处理后,出水COD<60 mg/L,ρ(氨氮)<1.0 mg/L,ρ(总酚)未检出,色度小于50倍,达到GB8978—1996《污水综合排放标准》中的一级排放标准。 相似文献
110.
The vegetable wastes and flower stems were co-digested to evaluate the anaerobic hydrolysis performance of difficultly biodegradable organic wastes by introducing readily biodegradable organic wastes. The experiments were carried out in batches. When the vegetable wastes were mixed with the flower stems at the dry weight ratio of 1 to 13, the overall hydrolysis rate increased by 8%, 12%, and 2% according to the carbon, nitrogen, and total solid (TS) conversion rate, respectively. While the dry weight ratio was designed as 1 to 3, there was a respective rise of 5%, 15%, and 4% in the conversion rate of carbon, nitrogen, and TS. The enhancement of anaerobic hydrolysis from the mixed vegetable wastes and flower stems can be attributed to the formation of volatile fatty acids (VFA) and nutrient supplement like nitrogen content. The maximum VFA concentration can achieve 1.7 g/L owing to the rapid acidification of vegetable wastes, loosing the structure of lignocellulose materials. The statistic bivariate analysis revealed that the hydrolysis performance was significantly related to the physical and biochemical compositions of the feeding substrate. Especially, the soluble carbon concentration in the liquid was significantly positively correlated to the concentration of nitrogen and hemicellulose, and negatively correlated to the concentration of carbon and lignocellulose in the feeding substrate, suggesting that the regulation and control of feedstock can have an important influence on the anaerobic hydrolysis of organic wastes. 相似文献