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41.
A new imidacloprid (IMI) degrading bacterium Z-9 (deposited number CGMCC 6648) was isolated and identified as Pseudoxanthomonas indica by 16S rRNA gene analysis. Two metabolites were identified as olefin and 5-hydroxy IMI by liquid chromatography-mass spectrometry and nuclear magnetic resonance analysis. P. indica CGMCC 6648 degraded 70.1% of IMI (1.22 mmol L?1) and formed 0.93 mmol L?1 5-hydroxy IMI and 0.05 mmol L?1 olefin IMI in 6 days and in the presence of 100 mmol L?1 glucose. The half-life of IMI degradation was 3.6 days. P. indica CGMCC 6648 transforms IMI via a co-metabolism mechanism and different carbohydrates have significant effects on 5-hydroxy IMI formation, whereas different organic acids have substantial effects on olefin IMI production. Lactose is the best co-substrate for IMI degradation and 5-hydroxy IMI formation with 0.77 mmol L?1 degraded and 0.67 mmol L?1 formed in 48 h, respectively. Pyruvate is the best co-substrate for olefin IMI formation with 0.17 mmol L?1 produced in 96 h for all carbon sources tested. Pyruvate significantly stimulates the conversion of 5-hydroxy IMI to olefin IMI, whereas glucose slightly inhibits this reaction. P. indica CGMCC 6648 rapidly degrades IMI and forms olefin IMI, which may enhance its potential for biodegradation of IMI and increase its insecticidal activity, which can decrease the IMI dosage required.  相似文献   
42.
翟由涛  刘莉 《环境科技》2003,16(4):37-38
对燃煤电厂的环评工作中,项目选址、总平面布置、污染防治与清洁生产:冷却塔噪声等一些值得注意的问题进行了探讨,并提出了一些初步意见。  相似文献   
43.
天然气应用对兰州大气环境的影响   总被引:3,自引:0,他引:3  
煤烟型污染是兰州市大气污染严重的主要原因之一,西气东输工程对改变兰州市能源结构,改善城市环境质量具有非常重要的意义。根据兰州市大气污染现状和特性,以2000年为基准,分析研究了兰州市利用天然气前后能源结构,主要污染源及大气污染物排放量的变化。针对污染源状况和兰州市天然气用气规划,选用适宜模式预测了兰州市利用天然气后的各主要污染物的年平均浓度,计算了空气质量的改善程度。  相似文献   
44.
Motor vehicles are major sources of fine particulate matter (PM2.5), and the PM2.5 from mobile vehicles is associated with adverse health effects. Traditional methods for estimating source impacts that employ receptor models are limited by the availability of observational data. To better estimate temporally and spatially resolved mobile source impacts on PM2.5, we developed an approach based on a method that uses elemental carbon (EC), carbon monoxide (CO), and nitrogen oxide (NOx) measurements as an indicator of mobile source impacts. We extended the original integrated mobile source indicator (IMSI) method in three aspects. First, we generated spatially resolved indicators using 24-hr average concentrations of EC, CO, and NOx estimated at 4 km resolution by applying a method developed to fuse chemical transport model (Community Multiscale Air Quality Model [CMAQ]) simulations and observations. Second, we used spatially resolved emissions instead of county-level emissions in the IMSI formulation. Third, we spatially calibrated the unitless indicators to annually-averaged mobile source impacts estimated by the receptor model Chemical Mass Balance (CMB). Daily total mobile source impacts on PM2.5, as well as separate gasoline and diesel vehicle impacts, were estimated at 12 km resolution from 2002 to 2008 and 4 km resolution from 2008 to 2010 for Georgia. The total mobile and separate vehicle source impacts compared well with daily CMB results, with high temporal correlation (e.g., R ranges from 0.59 to 0.88 for total mobile sources with 4 km resolution at nine locations). The total mobile source impacts had higher correlation and lower error than the separate gasoline and diesel sources when compared with observation-based CMB estimates. Overall, the enhanced approach provides spatially resolved mobile source impacts that are similar to observation-based estimates and can be used to improve assessment of health effects.

Implications: An approach is developed based on an integrated mobile source indicator method to estimate spatiotemporal PM2.5 mobile source impacts. The approach employs three air pollutant concentration fields that are readily simulated at 4 and 12 km resolutions, and is calibrated using PM2.5 source apportionment modeling results to generate daily mobile source impacts in the state of Georgia. The estimated source impacts can be used in investigations of traffic pollution and health.  相似文献   

45.
氧化-混凝法处理碱性高砷废水的实验研究   总被引:2,自引:0,他引:2  
对碱性高砷废水的处理进行了研究 ,针对常规混凝法除砷的缺点提出了氧化 混凝工艺。结果表明 ,用氧化 混凝工艺除砷效果显著 ,废水经处理后砷含量低于 0 5mg/L ,符合国家排放标准。氧化 混凝除砷的最佳工艺条件为 :pH值为 6— 7,H2 O2 用量为 2 5 % ,氧化时间为 10min ,Fe2 (SO4) 3 用量为 2 5g/L ,PAM用量为 11 2 5mg/L。  相似文献   
46.
工业循环经济发展区域分异研究--以江苏省为例   总被引:3,自引:0,他引:3  
依据工业循环经济发展的基本原则,构建了包括产业及社会发展、资源减量、循环利用、污染减排、资源与环境安全五类指标在内的区域工业循环经济发展评价指标体系.运用AHP(层次分析法)方法,测算了指标权重,并以江苏省13个地级市为例进行了研究.用2003年的数据,对13个地级市的工业循环经济发展状况进行了评价.研究结果表明,江苏省13个地级市的工业循环经济发展水平可以分为四个层次,第一层次(水平良好)的城市为无锡、苏州、常州;第二层次(水平中上)的城市为盐城、南通、泰州;第三层次(水平中等)的城市为扬州、镇江、徐州、南京、连云港;第四层次(水平较差)的城市为淮安、宿迁.从总体上看,南部好于北部,东部好于西部,沿江沿海地区要好于内陆地区,靠近工业产业带的地区好于远离工业产业带的地区.  相似文献   
47.
膨润土对Pb2+、Cu2+、Cr3+的吸附动力学及等温线研究   总被引:1,自引:0,他引:1  
研究所用膨润土的主要成分为SiO2和Al2O3,属于Ca基膨润土,BET表面积为50.83 m2/g.在恒温及恒定pH条件下,用静态吸附法研究了膨润土对Pb2 、Cu2 、Cr3 的吸附特性,结果表明其较好地符合Lagergten二级吸附速率方程,对这3种离子的吸附速率为Pb2 >Cu2 >Cr3 .利用3种等温线方程对吸附过程进行拟合,发现利用Langmuir吸附等温方程计算的值与膨润土吸附Pb2 、Cu2 、Cr3 试验数据最为吻合.膨润土对3种金属离子的平衡吸附量为Cr3 >Cu2 >Pb2 .  相似文献   
48.
To investigate formation mechanisms of secondary organic carbon(SOC) in Eastern China,measurements were conducted in an urban site in Shanghai in the summer of 2015. A period of high O_3 concentrations(daily peak 120 ppb) was observed, during which daily maximum SOC concentrations exceeding 9.0 μg/(C·m~3). Diurnal variations of SOC concentration and SOC/organic carbon(OC) ratio exhibited both daytime and nighttime peaks. The SOC concentrations correlated well with O_x(= O_3+ NO_2) and relative humidity in the daytime and nighttime, respectively, suggesting that secondary organic aerosol formation in Shanghai is driven by both photochemical production and aqueous phase reactions. Single particle mass spectrometry was used to examine the formation pathways of SOC. Along with the daytime increase of SOC, the number fraction of elemental carbon(EC) particles coated with OC quickly increased from 38.1% to 61.9% in the size range of 250–2000 nm, which was likely due to gas-to-particle partitioning of photochemically generated semi-volatile organic compounds onto EC particles. In the nighttime, particles rich in OC components were highly hygroscopic, and number fraction of these particles correlated well with relative humidity and SOC/OC nocturnal peaks. Meanwhile, as an aqueous-phase SOC tracer, particles that contained oxalate-Fe(III) complex also peaked at night. These observations suggested that aqueous-phase processes had an important contribution to the SOC nighttime formation. The influence of aerosol acidity on SOC formation was studied by both bulk and single particle level measurements, suggesting that the aqueous-phase formation of SOC was enhanced by particle acidity.  相似文献   
49.
纵观国外同类化学事故应急咨询机构30多年的发展经验,结合化学事故应急响应专线的现状,提出了扩大化学事故应急响应专线的服务范围、加强化学事故技术支持体系的建设及加强与国内外同类机构的交流与合作等发展建议。  相似文献   
50.
用span-80表面活性剂制作的乳状液处理垃圾渗滤液中氨氮,考察了表面活性剂span-80用量、膜内相硫酸浓度、膜增强剂用量、油内比、乳水比、外相水pH值因素对氨氮去除率的影响。结果表明,在最佳反应条件下,用乳状液膜分离法预处理垃圾渗滤液中的氨氮,分离速度快,处理效果达到87%以上。  相似文献   
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