新烟碱类农药的污染现状及转化行为研究进展

新烟碱类(neonicotinoids)农药自在20世纪80年代中期引入以来,便发展成为世界上使用最广泛的一类杀虫剂。近年来,该类化合物在环境中被不断检出,并通过饮用水和食物等方式进入食物链,给人类健康带来极大的安全隐患。文章综述了新烟碱类杀虫剂在空气、土壤、水相、生物体和人体中的暴露浓度,以及这类农药在环境中的转化行为。目前针对新烟碱类杀虫剂的环境暴露研究仍十分有限,需要更全面调查其在多环境介质中的暴露状况以综合评价其生态风险。关于新烟碱类化合物的毒理学研究主要集中在急性毒性试验,而对于其他形式的毒性效应有待进一步研究。最后对新烟碱农药未来的研究重点和方向提出了展望。     

Application and mechanism of polysaccharide extracted from Enteromorpha to remove nano-ZnO and humic acid in coagulation process

Green source Ep was extracted from marine alga waste. The molecule model structure of Ep was studied and constructed. PAC-Ep coagulation system improves the efficiency of removal efficiency. Synergistic effects between NPs and HA make a big difference to enhance efficiency. Mechanism is charge neutralization, hydrogen bonding and adsorbing-complexing Enteromorpha polysaccharide (Ep) extracted from alga a novel green coagulant aid for nanoparticles (NPs) and heavy metal ions removal and the structure of EP was intensively studied in this study. The integration of Ep with polyaluminum chloride (PAC-Ep) coagulants exhibited higher coagulation performance than that of the polyaluminum chloride (PAC) because of the negatively charged NPs suspension and humic aid (HA) solution. Significant high removal efficiencies of dissolved organic matter (94.1%), turbidity (99.3%) and Zn ions (69.3%) were achieved by the PAC-Ep coagulants. The dual-coagulation properties of PAC-Ep for different pollutants was based on multiple mechanisms, including (i) Al³⁺ charge neutralization; (ii) hydroxy aluminum hydroxyl bridging formed polynuclearhydroxy complexes bridge and sweep colloidal particles; (iii) adsorption and bridging of Ep chain for the NPs and heavy metal ions. Results indicated that the destabilization of colloid was induced by the coexisting HA and higher removal was achieved as ions adsorption was enhance in the presence of HA complexation. On the basis of that, the extraction of polysaccharide is a promising candidate for its high coagulation performance in water treatment.     

Species and distribution of rare earth elements in the Baotou section of the Yellow River in China

This paper analyses the contents and species distributions of rare earth elements (REEs) in the water-suspended particulate-sediment system of the Baotou section of the Yellow River, China, with known anthropogenic REE input from industrial discharges. The major forms of REEs were suspended and dissolved in the mainstream and the tributaries of the Baotou section, respectively. The concentrations of the dissolved and suspended REEs had the same trends in the overlying water along the mainstream, which increased from the Seqi section (site A) to the mouth of the Sidaosha River (site D), reaching a maximum value at site D, and tending to decrease thereafter. The contents of REEs in sediment cores showed enrichment with light rare earth elements (LREEs). The bound to carbonates and to Fe–Mn oxides are the major forms of REE in the secondary phase and the REE exhibited LREE enrichment pattern and moderate Eu depletion in suspended particulates and surface sediments. The contents and species distributions of REEs in the water-suspended particulate-sediment system of the Baotou section suggest that the anthropogenic source of REEs from Baotou city have enhanced REE accumulation to the Baotou section. This information is important for predicting possible pollution resulting from anthropogenic REE input into rivers.     

应用呼吸-滴定测量监测硝化动态过程

将pH值在线监测与药品自动投加系统与已开发的混合呼吸测量仪集成,组成自动呼吸-滴定测量仪,同时测定废水生物处理过程氧气利用速率(OUR)和质子变化速率(HVR).对活性污泥硝化过程定时测定NH4+-N浓度,比较其与基于HVR或OUR预测的NH4+-N浓度间的一致程度,评估自动滴定测量装置测试硝化过程动态的性能.结果表明,在初始NH4+-N浓度分别为20,25mg/L的间歇试验中,实测值数组与基于OUR的预测值数组间的相关系数分别为0.9967和0.9972,与基于HVR的预测值数组间的相关系数分别为0.9991和0.9992,表明OUR和HVR均能及时准确地反映硝化过程的动态特性.     

聚硅酸铝铁-壳聚糖复合絮凝剂的制备与应用

采用聚硅酸铝铁与壳聚糖复合,制备低成本、高絮凝性能的新型无机-有机复合絮凝剂。结果表明:最佳复合条件为pH值1.4～2.0、原料配比(质量比)1:1、最佳温度70～80℃、反应时间16h。并将该絮凝剂用于造纸废水的处理实验,在投加量每500mL为5mL时,其对废水浊度、色度和COD的去除率分别为94.5%,61.5%和78.7%。     

一株好氧反硝化细菌的分离鉴定及反硝化能力

利用驯化活性污泥的方法筛选出一株好氧反硝化细菌G3,该菌在碳源充足且溶解氧为(4.0±1.0)mg·L-1条件下,24h内对NO-2-N积累量为12.03 mg·L-1,对NO-3-N的去除率为91.09%.扫描电镜观察其形态特征为(0.4～0.6)μm×(1.2～2.0)μm的短杆菌.16SrDNA序列分析表明,该菌与Pseudomonas stutzeri的相似性为100%.利用MEGA软件对该菌株与已报道的相关微生物进行系统发育分析,并克隆出与好氧反硝化相关的周质硝酸盐还原酶的亚基napA基因,初步判定筛选菌株具有周质硝酸盐还原酶.     

油田作业人员安全培训的信息化管理

1 问题的提出 胜利油田各培训机构多年来为油田培养了大批的专业人才。但是,目前安全教育培训仍然采用传统的面对面的教学管理方式,培训计划、培训人员、办班情况、培训内容、成绩单等信息均采用人工记录,上报安全处、劳资处等管理部门的材料还是采用传统的纸质材料,工作效率受到限制。     

兰州市循环经济型生态城市建设探讨

生态城市建设是城市持续健康发展的重要途径,建立城市循环经济体系是生态城市建设的必由之路。文章对循环经济和生态城市的内涵与本质进行了探讨,对兰州市循环经济理念下的城市生态建设的背景和必要性进行了分析,并在此基础上提出了诸如加强政府的政策导向、行为示范的主导作用、优化兰州城市产业结构,促进经济发展、建立生态工业园区、加强污染治理,改善城市生态环境等一些对策和建议,以促进兰州市循环经济型生态城市建设的快速发展。     

离子色谱在气溶胶无机离子测定中的应用

综述了离子色谱技术在气溶胶可溶性无机离子测定中的应用。离子色谱技术的主要优点是检测时间短、耗费样品量少和分辨率高。它克服了化学分析法的缺点,已经成为一种优秀的样品分析检测技术,气溶胶可溶性无机离子测定中采用这一技术是很有价值的。介绍了离子色谱的原理,仪器的组成与操作,并以气溶胶中无机离子的测定流程为主线,分别概述了采样与样品处理的方法和注意事项,分离柱与淋洗液的选择和影响因素,抑制器与检测器的发展和最新动态。     

基于PCA和SOM网络的洪泽湖水质时空变化特征分析

2010年分4个季度对洪泽湖全湖20个样点的水质理化特征进行了定期监测,采用修正的卡尔森营养状态指数法（TSIm）综合评价了洪泽湖水质的营养状况,同时应用主成分分析（PCA）和自组织特征映射网络（SOM网络）分析了洪泽湖水质的时空变化特征。结果显示：除了水深（WD）和透明度（SD）,洪泽湖的pH、EC、NH+4 N、TN、TP、和CODMn等水质参数季节差异显著。TSIm综合评价结果表明洪泽湖4个季节的水质均呈富营养化状态,夏季富营养化程度最严重。PCA分析表明洪泽湖水质主要受离子和氮盐的控制,磷不是控制洪泽湖水质的最主要因素。SOM网络将全湖20个样点聚为G1、G2和G3三类,G1代表洪泽湖相对封闭的北部区域,有沉水植被分布,水质主要受围网养殖污染的影响;G2代表洪泽湖东部和南部区域,〖JP2〗航运繁忙,直接承接淮河入湖河水,水质主要受淮河入湖河水和航运的影响;G3代表洪泽湖西部水域,沿岸密布养殖池塘且人口密度大,水质主要受养殖废水和城镇生活污水的影响。研究认为,控制外源污染和恢复沉水植被是防治洪泽湖富营养化的有效途径