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541.
The influence of CO2 content and presence of SO2 on the sequestration of CO2 by municipal solid waste incinerator(MSWI) fly ash was studied by investigating the carbonation reaction of MSWI fly ash with different combinations of simulated flue gas.The reaction between fly ash and 100% CO2 was relatively fast;the uptake of CO2 reached 87g CO2/kg ash,and the sequestered CO2 could be entirely released at high temperatures.When CO2 content was reduced to 12%,the reaction rate decreased;the uptake fell to 41g CO2/kg ash,and 70.7% of the sequestered CO2 could be released.With 12% CO2 in the presence of SO2,the reaction rate significantly decreased;the uptake was just 17g CO2/kg ash,and only 52.9% of the sequestered CO2 could be released.SO2 in the simulated gas restricted the ability of fly ash to sequester CO2 because it blocked the pores of the ash.  相似文献   
542.
Environmental Science and Pollution Research - PEN is a widely used triazole fungicide, usually used to control grape white rot. In the process of agricultural use, PEN will be scattered to the...  相似文献   
543.

To investigate the effect of chiral pesticide fenvalerate (FV) on the micro-ecological environment of aquaculture pond sediment, we used an indoor static experiment to observe the effects of FV added at different concentrations with different chiral isomers on the changes in the sediment bacterial community. The 16S rDNA high-throughput sequencing technique was used to conduct sequencing and analysis of the bacterial community structure as well as changes in aquaculture pond sediments after 4 weeks of cultivation. The results showed that the microbial alpha diversity indices (Sobs and Shannon indices) of the treated groups were significantly lower than those of the control group after 4 weeks (P < 0.05), and the values in the high-concentration group were significantly lower than those of the low-concentration group (P < 0.05). In terms of bacterial group composition, the proportion of abundance of Proteobacteria and Acidobacteria in the treated groups were greater than in the control group after 4 weeks, while the proportion of abundance of Bacteroidetes and Verrucomicrobia were lower. In the high-concentration FV treatment group, the proportion of abundance of Bacteroidetes, Acidobacteria, Chloroflexi, Nitrospinae, unclassified_k_norank, Ignavibacteriae, and Nitrospirae were significantly different from those of the other groups (P < 0.05). Principal coordinate analysis (PCoA) and ANONISIM/Adonis analysis showed that the cis-enantiomer had a stronger effect on the bacterial community as the concentration of FV increased. In addition, the linear discriminant analysis effect size (LEfSe) and linear discriminant analysis (LDA) results revealed differences in the level of enrichment of bacterial groups caused by FV at different concentrations and isomer levels. Collectively, this study showed that FV residue has a pronounced effect on bacterial communities in sediment, which becomes more significant with increasing exposure concentration. The effects of the cis- and trans-enantiomers of FV on the sediment environment are different; the cis-enantiomer has a stronger effect on the bacterial community.

  相似文献   
544.
Environmental Science and Pollution Research - Identifying sources of nitrate contamination has been a long-term challenge in areas with different land uses. We investigated the biogeochemical...  相似文献   
545.
当前国际形势下,中国半导体行业不断创新发展。由于半导体行业的工艺技术特点,生产过程中必然涉及各类易燃易爆、有毒有害化学品。根据半导体生产行业特征及其环境风险水平,提出环境风险预防、控制、减缓措施,明确环境风险防范及应急要求,运用科学的技术手段和管理方法,尽可能降低环境风险事故发生。  相似文献   
546.
为探索吕梁地区PM2.5中多环芳烃的季节变化、健康风险和潜在来源,于2018年10月23日至2019年7月1日对离石区(市区)和孝义市(郊区)进行PM2.5样品采集,利用气相色谱-质谱联用仪(GC-MS)测定了14种多环芳烃浓度.总多环芳烃的浓度年均值为95.50 ng·m-3,主要以5~6环为主(49.7%),3环占比较低(8.3%);吕梁市多环芳烃浓度呈现冬季>秋季>春季>夏季的季节性变化规律,市区浓度年均值(130.47 ng·m-3)高于郊区(84.4 ng·m-3);增量终身致癌风险和蒙特卡洛模拟结果均表明吕梁市多环芳烃毒性服从成人>青年>儿童的规律,除夏季外,离石区增量终身致癌风险值均在10-6~10-4之间,远高于孝义市,表明市区存在较高的多环芳烃潜在风险;通过采用特征比值法和正定矩阵因子分解模型表明,吕梁市多环芳烃主要来自于煤和生物质的燃烧(61.9%)和机动车尾气排放(38.1%),由后...  相似文献   
547.
The submicron particulate matter (PM1) and fine particulate matter (PM2.5) are very important due to their greater adverse impacts on the natural environment and human health. In this study, the daily PM1 and PM2.5 samples were collected during early summer 2018 at a sub-urban site in the urban-industrial port city of Tianjin, China. The collected samples were analyzed for the carbonaceous fractions, inorganic ions, elemental species, and specific marker sugar species. The chemical characterization of PM1 and PM2.5 was based on their concentrations, compositions, and characteristic ratios (PM1/PM2.5, AE/CE, NO3?/SO42?, OC/EC, SOC/OC, OM/TCA, K+/EC, levoglucosan/K+, V/Cu, and V/Ni). The average concentrations of PM1 and PM2.5 were 32.4 µg/m3 and 53.3 µg/m3, and PM1 constituted 63% of PM2.5 on average. The source apportionment of PM1 and PM2.5 by positive matrix factorization (PMF) model indicated the main sources of secondary aerosols (25% and 34%), biomass burning (17% and 20%), traffic emission (20% and 14%), and coal combustion (17% and 14%). The biomass burning factor involved agricultural fertilization and waste incineration. The biomass burning and primary biogenic contributions were determined by specific marker sugar species. The anthropogenic sources (combustion, secondary particle formation, etc) contributed significantly to PM1 and PM2.5, and the natural sources were more evident in PM2.5. This work significantly contributes to the chemical characterization and source apportionment of PM1 and PM2.5 in near-port cities influenced by the diverse sources.  相似文献   
548.
在分析2017年3月至2018年2月汉丰湖水体氮磷营养盐质量浓度季节性变化的基础上,利用氮磷化学计量摩尔比评估水体氮磷养分限制状态.结果表明:湖体TN、DN和NO3--N平均质量浓度分别为1.60、1.25和0.91 mg·L-1,三者季节变化过程相似,均呈现出冬季最高、夏季最低的特点.NO3--N对水体TN贡献较大,NH4+-N和NO2--N质量浓度维持在较低水平且变化平稳.TP、DP和PO43--P平均质量浓度分别为0.13、0.09和0.06 mg·L-1,TP和DP质量浓度变化相似,呈春夏季升高,秋冬季先降低再升高的趋势,而PO43--P质量浓度则波动降低.TN/TP范围在11.07~56.02之间,均值为29.23,TN/TP呈季节性波动变化,最高值出现在冬季,最低值出现在夏季.汉丰湖水体多数时间适宜藻类生长繁殖,少数时间处于N限制状态,极少数时间处于P限制状态.降雨径流、肥料使用、污水排放和水生生物活动等因素皆会影响TN/TP的季节变化,同时根据汉丰湖水质特征提出保护建议.  相似文献   
549.
Paddy soil and irrigation water are commonly contaminated with hexavalent chromium [Cr(VI)] near urban industrial areas, thereby threatening the safety of agricultural products and human health. In this study, we develop a porous and high specific area bone char (BC) to support nanoscale zero-valent iron (nZVI) and apply it to remediate Cr(VI) pollution in water and paddy soil under anaerobic conditions. The batch experiments reveal that BC/nZVI exhibits a higher removal capacity of 516.7 mg/(g?nZVI) for Cr(VI) than nZVI when normalized to the actual nZVI content, which is 2.8 times that of nZVI; moreover, the highest nZVI utilization is the nZVI loading of 15% (BC/nZVI15). The Cr(VI) removal efficiency of BC/nZVI15 decreases with increasing pH (4 – 10). Coexisting ions (phosphate and carbonate) and humic acid can inhibit the removal of Cr(VI) with BC/nZVI15. Additionally, BC exhibits a strong advantage in promoting Cr(VI) removal by nZVI compared to the widely used biochar and activated carbon. Our results demonstrate that reduction and coprecipitation are the dominant Cr(VI) removal mechanisms. Furthermore, BC/nZVI15 shows a significantly higher reduction and removal efficiency as well as a strong anti-interference ability for Cr(VI) in paddy soil, as compared to nZVI. These findings provide a new effective material for remediating Cr(VI) pollution from water and soil.  相似文献   
550.
陈田  潘竟虎 《中国环境科学》2022,42(12):5549-5560
以中国340个地级及以上城市为研究对象,采用自下而上的核算方法,针对农业活动、能源活动和废物处理3个一级CH4排放源,核算2009年和2019年中国人为CH4排放量并分析其时空格局.结果表明:2009年中国人为CH4总排放40.71Tg,2019年为42.89Tg,CH4排放总量在增加,排放强度和人均排放量基本保持不变.一级排放源中,农业活动、能源活动和废物处理在2009年的CH4排放量分别为24.88Tg、12.06Tg和3.76Tg,农业活动为主要排放源,2019年三者排放量分别为16.99Tg、21.62Tg和4.28Tg,能源活动成为主要排放源;二级排放源中煤炭开采的CH4排放最多;不同城市中各排放源的占比存在较大差异,淮安、扬州和南通农业活动排放最多,晋城、大同和太原能源活动排放最多,而北京、上海和广州以废物处理排放为主.城市人为CH4排放存在显著的空间正相关,高排放—高聚集的城市数量减少,分布集中;低排放—低聚集的城市数量增加,分布重心向东部地区转移;局部城市空间关联类型呈现出较强的空间锁定效应和迁移惰性特征.CH4排放强度与人均CH4排放的区域总体差异较大;CH4排放强度地区间Theil指数差异较大,而地区内差异较小;人均CH4排放地区间与地区内的Theil指数差异均较小.  相似文献   
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