SPE和LC-MS／MS联用同时检测水体中的15种抗生素

采用（SPE）固相萃取柱进行分离富集,使用LC—MS／MS联用仪进行检测,建立了一种高效、低成本的可同时检测水体中多种抗生素的方法,并在河北省子牙河流域汪洋沟水体抗生素污染现状调查中得到应用。实验结果表明,（1）最优实验条件的选择为：水样体积为1L,洗脱剂用量为10mL,pH为3．0;（2）回收率达到69．2％～86．3％,相对标准偏差在1．8％～8．4％之间,表明检测结果准确度和灵敏度均较高;（3）在所检测的15种抗生素中,头孢西丁、土霉素、氯唑西林和布洛芬4种抗生素是该河流的主要抗生素污染物,其含量比重（中位数）高达73．5％,检测浓度最高（中位数）的是磺胺类抗生素,浓度为100．4ng／L;（4）各抗生素的含量从上游到下游大体呈逐渐衰减的趋势,这主要归因于下游支流的稀释作用,但水体中抗生素浓度仍远高于已有报道的地区;（5）污染源解析表明,水体中抗生素主要来源于制药企业的废水,部分来源于附近居民的生活污水。     

Distribution of antibiotic resistance genes and their association with bacteria and viruses in decentralized sewage treatment facilities

• Distribution of ARGs in decentralized sewage facilities were investigated. • Bacitracin-ARGs were most predominant ARGs in rural wastewater. • ARGs were identified in bacterial and viral community. • ARGs of rpoB, drfE, gyrA and parC were both correlated with bacteria and phages. • More attention should be paid to the risk of spreading ARG by phages. The distribution of antibiotic resistance genes (ARGs) has been intensively studied in large-scale wastewater treatment plants and livestock sources. However, small-scale decentralized sewage treatment facilities must also be explored due to their possible direct exposure to residents. In this study, six wastewater treatment facilities in developed rural areas in eastern China were investigated to understand their risks of spreading ARGs. Using metagenomics and network analysis tools, ARGs and bacterial and viral communities were identified in the influent (INF) and effluent (EFF) samples. The dominant ARGs belonged to the bacitracin class, which are different from most of municipal wastewater treatment plants (WWTPs). The dominant hosts of ARGs are Acidovorax in bacterial communities and Prymnesiovirus in viral communities. Furthermore, a positive relationship was found between ARGs and phages. The ARGs significantly correlated with phages were all hosted by specific genera of bacteria, indicating that phages had contributed to the ARG’s proliferation in sewage treatment facilities. Paying significant concern on the possible enhanced risks caused by bacteria, viruses and their related ARGs in decentralized sewage treatment facilities is necessary.     

信息素调控质粒介导的粪肠球菌耐药基因接合转移机制研究进展

粪肠球菌是一种在自然环境中广泛存在的革兰氏阳性细菌.由于其特殊的耐药机制及高频率的耐药基因转移方式,导致了环境中耐药粪肠球菌的广泛传播,生态安全形势严峻.其中,信息素应答质粒介导的粪肠球菌耐药基因的接合转移是造成粪肠球菌耐药基因快速扩散的重要方式.本文回顾了近些年关于信息素应答质粒接合转移的研究成果,分析总结了接合转移的必要条件、正负调控信息素对接合转移的调节作用,并以携带四环素抗性的质粒pCF10为例简要探讨了接合转移相关基因、蛋白的调控机制,旨在更加全面地揭示粪肠球菌的耐药基因传播机制,为耐药细菌的基因转移机制研究提供参考.     

双酚芴的清洁生产工艺

根据清洁生产的理论与思维模式,对生产双酚芴的传统工艺进行了改进,以强酸性阳离子交换树脂代替传统的催化剂催化合成双酚芴,以沸水代替甲醇水溶液洗涤反应混合物,产生的废液经液液萃取和蒸馏处理,使苯酚等有效组分被回收利用,解决了废液的排放问题,基本实现了双酚芴产品的清洁生产。采用清洁生产工艺生产双酚芴,每生产1t产品可从废液中回收1．6t苯酚,按30t／a计算,可节约资金约43．2万元/a。与传统工艺相比,双酚芴的清洁生产工艺在经济效益和环境效益方面有明显优势。     

溶解性微生物产物数学模型的研究进展

溶解性微生物产物(SMP)数学模型对于控制废水生物处理出水中COD具有极其重要的作用.按照SMP模型发展过程,即从只包含其形成机制模型到包含其形成与降解机制模型的发展过程,详细介绍了SMP模型的研究进展.同时,综述了SMP数学模型在活性污泥法和生物膜法等工艺中的应用,并在此基础上提出了活性污泥数学模型的发展方向.     

Effects of conversion of mangroves into gei wai ponds on accumulation,speciation and risk of heavy metals in intertidal sediments

Environmental Geochemistry and Health - Mangroves are often converted into gei wai ponds for aquaculture, but how such conversion affects the accumulation and behavior of heavy metals in sediments...     

Continuous electrocoagulation degradation of oily wastewater with Fe78Si9B13 amorphous ribbons

Environmental Science and Pollution Research - The oily wastewater was treated by electrocoagulation with Fe78Si9B13 amorphous ribbons as anode and graphite plates as cathode under such processing...     

A study of peroxyacetyl nitrate at a rural site in Beijing based on continuous observations from 2015 to 2019 and the WRF-Chem model

•PAN concentrations at a rural site near Beijing were monitored from 2015 to 2019. •PAN concentrations exhibited high values in spring and low values in winter. •Anomalously southerlies induced extreme high PAN concentration in spring 2018. Peroxyacetyl nitrate (PAN) is one of the most important photochemical pollutants and has aroused much concern in China in recent decades. However, few studies described the long-term variations in PAN in China. In this study, we continuously monitored the PAN, O₃ and NO_x concentrations at a regional background site near Beijing from August 2015 to February 2019. Based on the observed concentrations and climate data, we analyzed the seasonal PAN variations. The results revealed that the monthly mean PAN concentration ranged from 0.33–2.41 ppb, with an average value of 0.94 ppb. The PAN concentration exhibited a distinct seasonal variation, with high values in spring and low values in winter. After analyzing the corresponding meteorological data, we found that stronger ultraviolet (UV) radiation, a relatively longer lifetime and a higher background PAN concentration contributed to the high PAN concentrations in spring. In addition, with the utilization of the WRF-Chem (Weather Research and Forecasting with Chemistry) model, the cause of the extremely high PAN concentration in spring 2018 was determined. The model results demonstrated that an anomalously low pressure and the southwesterly winds in northern China might be the main causes of the increased PAN concentration in Beijing and its surrounding area in spring 2018.     

HSE管理在装置检修中的应用

中原油田第四气体处理厂装置于2006年4月8日停运检修.本次检修有如下5个特点:一是工期短,即从装置停工到开工投用仅为20天,为历史最短;二是任务重,需动用吊车拆装校验安全阀98个,更换部分塔盘等检修项目12项;三是施工危险性大,施工队伍安全管理水平参差不齐;四是检修难度大,高处交叉作业多,临时作业人员多;五是检修复杂性大,部分检修人员对现场环境不熟悉,造成检修工作相对复杂.为此,将本次大修分成5个阶段:即检修前准备阶段、装置停气吹扫阶段、检修施工阶段、检查验收阶段和装置开工投产阶段,然后结合各个阶段HSE管理的特点、难点、重点,有针对性地抓好各阶段的HSE管理工作,实现了零事故检修的目标.     

Issues with using police citations to assign responsibility in quasi-induced exposure

Crash fault determination is one of the most critical issues in applications of quasi-induced exposure. Traditionally, the driver citation issued by the investigating police officer is the primary source to assign responsibility for motor vehicle crashes. Such citations are based on the “evidence” or observation of a moving violation (such as engaged hazardous actions) in combination with non-moving violations (such as suspended driver license) prior to the crash. The objective here is to identify the contributing factors that may lead to driver citations in two-vehicle crashes in addition to the hazardous action. Multivariate binary logistic regression modeling is employed to explore the behavior of the investigating police officer in terms of issuing citation at the crash scene. A series of explanatory parameters including roadway characteristics, environmental factors, and driver and vehicle attributes is assessed. The results show that whether the crash type was a hit-and-run, alcohol and illegal drug use, driver gender, driver age, and injury severity all appear to have significant impacts on the investigating officer’s decision-making. Specific examples are given to demonstrate how two factors hit-and-run and drinking status can skew the exposure estimates in the context of quasi-induced exposure. The findings will help to serve as a basis to select appropriate parameters in assigning crash responsibility in quasi-induced exposure applications; and we make recommendations to modify existing crash database for better safety research in the future.