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951.
Ye  Zi  Wang  Bin  Mu  Ge  Zhou  Yun  Qiu  Weihong  Yang  Shijie  Wang  Xing  Zhang  Zhuang  Chen  Weihong 《Environmental science and pollution research international》2021,28(46):65140-65149
Environmental Science and Pollution Research - Fine particulate matter (PM2.5) is still the primary air pollutant in most Chinese cities and its adverse effects on lung function have been widely...  相似文献   
952.
•Strong ENSO influence on AOD is found in southern China region. •Low AOD occurs in El Niño but high AOD occurs in La Niña events in southern China. •Angstrom exponent anomalies reveals the circulation pattern during each ENSO phase. •ENSO exerts large influence (70.5%) on annual variations of AOD during 2002–2020. •Change of anthropogenic emissions is the dominant driver for AOD trend (2002–2020). Previous studies demonstrated that the El Niño–Southern Oscillation (ENSO) could modulate regional climate thus influencing air quality in the low-middle latitude regions like southern China. However, such influence has not been well evaluated at a long-term historical scale. To filling the gap, this study investigated two-decade (2002 to 2020) aerosol concentration and particle size in southern China during the whole dynamic development of ENSO phases. Results suggest strong positive correlations between aerosol optical depth (AOD) and ENSO phases, as low AOD occurred during El Niño while high AOD occurred during La Niña event. Such correlations are mainly attributed to the variation of atmospheric circulation and precipitation during corresponding ENSO phase. Analysis of the angstrom exponent (AE) anomalies further confirmed the circulation pattern, as negative AE anomalies is pronounced in El Niño indicating the enhanced transport of sea salt aerosols from the South China Sea, while the La Niña event exhibits positive AE anomalies which can be attributed to the enhanced import of northern fine anthropogenic aerosols. This study further quantified the AOD variation attributed to changes in ENSO phases and anthropogenic emissions. Results suggest that the long-term AOD variation from 2002 to 2020 in southern China is mostly driven (by 64.2%) by the change of anthropogenic emissions from 2002 to 2020. However, the ENSO presents dominant influence (70.5%) on year-to-year variations of AOD during 2002–2020, implying the importance of ENSO on varying aerosol concentration in a short-term period.  相似文献   
953.
• Over 70% reduction of sulfate was achieved for sulfate less than 12000 mg/L. • The decrease of genes encoding (EC: 1.3.8.1) induced the accumulation of VFAs. • The sulfate reduction genes were primary carried by genus Desulfovibrio. • Sulfate favored assimilatory, but inhibited dissimilatory sulfate reduction process. For comprehensive insights into the influences of sulfate on performance, microbial community and metabolic pathways in the acidification phase of a two-phase anaerobic system, a laboratory-scale acidogenic bioreactor was continuously operated to treat wastewater with elevated sulfate concentrations from 2000 to 14000 mg/L. The results showed that the acidogenic bioreactor could achieve sulfate reduction efficiency of greater than 70% for influent sulfate content less than 12000 mg/L. Increased sulfate induced the accumulation of volatile fatty acids (VFAs), especially propionate and butyrate, which was the primary negative effects to system performance under the high-sulfate environment. High-throughput sequencing coupled with PICRUSt2 uncovered that the accumulation of VFAs was triggered by the decreasing of genes encoding short-chain acyl-CoA dehydrogenase (EC: 1.3.8.1), regulating the transformation of propanoyl-CoA to propenoyl-CoA and butanoyl-CoA to crotonyl-CoA of propionate and butyrate oxidation pathways, which made these two process hardly proceed. Besides, genes encoding (EC: 1.3.8.1) were mainly carried by order Clostridiales. Desulfovibrio was the most abundant sulfate-reducing bacteria and identified as the primary host of dissimilatory sulfate reduction functional genes. Functional analysis indicated the dissimilatory sulfate reduction process predominated under a low sulfate environment, but was not favored under the circumstance of high-sulfate. With the increase of sulfate, the assimilatory sulfate reduction process finally overwhelmed dissimilatory as the dominant sulfate reduction pathway in acidogenic bioreactor.  相似文献   
954.
高锰酸钾与氯胺联合预氧化强化低温低浊水处理   总被引:1,自引:0,他引:1  
为了探讨对低温、低浊水更为有效的预氧化技术,通过小试考察了高锰酸钾与氯胺联合预氧化工艺在助凝、助滤、去除有机物及减少氯化消毒副产物方面的效能.结果表明:与单独氯胺预氧化工艺相比,高锰酸钾与氯胺联合预氧化具有明显的强化助凝和助滤作用,在最佳质量浓度时,可使沉后及滤后水浊度去除率分别达到94%和98%以上;并具有明显地降低沉后有机污染指标的效能,使沉后水中UV254和CODMn指标分别降低23%和32%;还能够有效地控制THMs的生成,KMnO4质量浓度为2 mg/L时,THMs去除率达85.2%,同时还可去除CHBr2Cl、CHBr3两种副产物.因此高锰酸钾与氯胺联合预氧化是一种对低温低浊水十分有效的水处理技术.  相似文献   
955.
随着教育改革的深入,幼儿教育界的改革也随之而深入,新的《幼儿园教育纲要》对开展幼儿环境教育提出更高的要求,幼儿环境教育是更加重要。在幼儿环境教育中必须以幼儿的真实生活环境为课堂,运用"互动式"教育,不宜作为一个单独的学习领域或知识领域,而应以渗透为主,开展幼儿环境教育。  相似文献   
956.
环境介质中的重金属种类繁多,而且含量高低不一。快速、准确地测定土壤及植物中的重金属含量是环境监测的重要任务之一。本文建立了金属罐消解—电感耦合等离子体发射光谱法(ICP-OES)同时测定土壤及植物中Cu、Pb、Zn的测试方法。试验表明,土壤及植物分别经HNO3-HF(2∶1)和HNO3-HF(2∶0.2)在190℃和150℃加热消解后完全分解溶出。经国家一级土壤及植物标准物质样品测定验证,结果与标准值吻合。土壤中Cu、Pb、Zn的加标回收率分别为99.4%~101.4%、99.5%~101.9%、99.7%~100.5%,RSD分别为2.05%、2.01%、1.79%;植物中Cu、Pb、Zn的加标回收率分别为99.3%~101.2%、96.9%~106.2%、99.7%~100.4%,RSD分别为2.84%、1.05%、0.985%。  相似文献   
957.
该文根据2003~2009年陕西省工业废水的排放情况进行分析,采用灰色系统理论,引入二阶弱化算子D2,建立陕西省工业废水排放量GM(1,1)预测模型。采用残差大小和均方差比值对缓冲序列预测数据进行精度分析,误差较小,精度较高,模型可靠,可满足预测要求。运用预测模型对陕西省“十二五”期间工业废水排放量进行预测,得到2011-2015年工业废水排放量。对预测结果进行分析,计算出废水达标排放量年均增长量为395.42万吨;与工业总产值相联系,知工业废水排放量随着工业总产值的增加相应有所增加。  相似文献   
958.
High performance size exclusion chromatography (HPSEC) is used in water quality research primarily to determine the molecular weight distribution of the dissolved organic matter (DOM), but by applying peak fitting to the chromatogram, this technique can also be used as a tool to model and predict DOM removal. Six low specific UV absorbance (SUVA) source waters were treated using coagulation with alum and both the source and treated water samples were analysed using HPSEC. By comparing the molecular weight profiles of the source and treated waters, it was established that several DOM components were not effectively removed by alum coagulation even after high dosage alum treatment. A peak-fitting technique was applied based on the concept of linking the character (molecular weight profile) of the recalcitrant organics in the treated water with those of the source water. This was then applied to predict DOM treatability by determining the areas of the peaks which were assigned to removable organics from the source water molecular weight profile after peak fitting, and this technique quantified the removable and non-removable organics. The prediction was compared with the actual dissolved organic carbon (DOC) removal determined from jar testing and showed good agreement, with variance between 2% and 10%. This confirmed that this prediction approach, which was originally developed for high SUVA waters, can also be applied successfully to predict DOC removal in low SUVA waters.  相似文献   
959.
叶绿素是城市水体富营养化的重要表征参数.以北京城区重点水体为研究对象,利用2011年6月8日TM遥感影像及同步获取的实测数据,在对TM数据进行几何校正和大气校正等预处理的基础上,选取相关性最大的TM2/(TM1 +TM4)波段组合进行叶绿素a浓度反演;利用2008 ~ 2010年的历史TM影像及人工水质站点准同步的实测数据,对模型的精度及适用性进行分析得出:回归模型适用于30 m以上的北京城区水体叶绿素a浓度监测,相对误差为17.04%.  相似文献   
960.
水是生产、生活不可或缺、不可替代的自然资源。生活污水因水质较矿井水差,处理后回用途径受限。结合国家的环保形势,回顾晋煤集团生活污水的处理、利用情况,介绍处理、利用现状。  相似文献   
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