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371.
鄱阳湖流域农村生活区面源污染特征及其影响 总被引:5,自引:0,他引:5
农村生活区水环境是流域水环境的重要组成部分。鄱阳湖流域是我国的重要农业生产区,农村人口众多,未经过处理的生活污水、生活垃圾和固体废弃物、分散畜禽养殖污染由于无序排放导致了鄱阳湖流域河湖水质下降,湖泊富营养化指数升高。通过采用污染物当量算法对鄱阳湖流域农村生活区面源污染估算,分析了1991~2011年农村生活污染现状及其趋势,并分析了鄱阳湖河湖水质变化趋势及其在农村生活区面源污染中的影响因子。研究结果表明:(1)1991~2011年,鄱阳湖流域农村人口、生活污染、生活垃圾和固体废弃物污染、分散畜禽养殖污染不断增加,其中农村生活污水污染物排放量、TN、TP和COD排放量增长了1268%,年平均增长量分别为036、002、1681和021万t;固体废弃物排放量、TN和TP排放量增加了1268%,年增长量分别为362、076和080万t;分散畜禽养殖污染TN、TP和COD的含量分别增长了9913%、6384%和7227%,年均增长量分别为022、003和009万t;(2)2000年以来,鄱阳湖流域河湖水质呈下降趋势,其中鄱阳湖湖泊的水质和富营养化指数下降趋势分别在001和005水平上具有显著性;(3)鄱阳湖流域农村生活区面源污染对流域水环境具有一定的影响,其中分散畜禽养殖污染的影响相对较大 相似文献
372.
373.
Current status and historical variations of phthalate ester (PAE) contamination in the sediments from a large Chinese lake (Lake Chaohu) 总被引:1,自引:0,他引:1
Lei Kang Qing-Mei Wang Qi-Shuang He Wei He Wen-Xiu Liu Xiang-Zhen Kong Bin Yang Chen Yang Yu-Jiao Jiang Fu-Liu Xu 《Environmental science and pollution research international》2016,23(11):10393-10405
The residual levels of phthalate esters (PAEs) in the surface and two core sediments from Lake Chaohu were measured with a gas chromatograph–mass spectrometer (GC–MS). The temporal–spatial distributions, compositions of PAEs, and their effecting factors were investigated. The results indicated that di-n-butyl phthalate (DnBP), diisobutyl phthalate (DIBP), and di(2-ethylhexyl) phthalate (DEHP) were three dominant PAE components in both the surface and core sediments. The residual level of total detected PAEs (∑PAEs) in the surface sediments (2.146?±?2.255 μg/g dw) was lower than that in the western core sediments (10.615?±?9.733 μg/g) and in the eastern core sediments (5.109?±?4.741 μg/g). The average content of ∑PAEs in the surface sediments from the inflow rivers (4.128?±?1.738 μg/g dw) was an order of magnitude higher than those from the lake (0.323?±?0.093 μg/g dw), and there were similar PAE compositions between the lake and inflow rivers. This finding means that there were important effects of PAE input from the inflow rivers on the compositions and distributions of PAEs in the surface sediments. An increasing trend was found for the residual levels of ΣPAEs, DnBP, and DIBP from the bottom to the surface in both the western and eastern core sediments. Increasing PAE usage with the population growth, urbanization, and industrial and agricultural development in Lake Chaohu watershed would result in the increasing production of PAEs and their resulting presence in the sediments. The significant positive relationships were also found between the PAE contents and the percentage of sand particles, as well as TOC contents in the sediment cores. 相似文献
374.
Research and application of method of oxygen isotope of inorganic phosphate in Beijing agricultural soils 总被引:1,自引:0,他引:1
Liyan Tian Qingjun Guo Yongguan Zhu Huijun He Yunchao Lang Jian Hu Han Zhang Rongfei Wei Xiaokun Han Marc Peters Junxing Yang 《Environmental science and pollution research international》2016,23(23):23406-23414
Phosphorus (P) in agricultural ecosystems is an essential and limited element for plants and microorganisms. However, environmental problems caused by P accumulation as well as by P loss have become more and more serious. Oxygen isotopes of phosphate can trace the sources, migration, and transformation of P in agricultural soils. In order to use the isotopes of phosphate oxygen, appropriate extraction and purification methods for inorganic phosphate from soils are necessary. Here, we combined two different methods to analyze the oxygen isotopic composition of inorganic phosphate (δ18OP) from chemical fertilizers and different fractions (Milli-Q water, 0.5 mol L?1 NaHCO3 (pH = 8.5), 0.1 mol L?1 NaOH and 1 mol L?1 HCl) of agricultural soils from the Beijing area. The δ18OP results of the water extracts and NaHCO3 extracts in most samples were close to the calculated equilibrium value. These phenomena can be explained by rapid P cycling in soils and the influence of chemical fertilizers. The δ18OP value of the water extracts and NaHCO3 extracts in some soil samples below the equilibrium value may be caused by the hydrolysis of organic P fractions mediated by extracellular enzymes. The δ18OP values of the NaOH extracts were above the calculated equilibrium value reflecting the balance state between microbial uptake of phosphate and the release of intracellular phosphate back to the soil. The HCl extracts with the lowest δ18OP values and highest phosphate concentrations indicated that the HCl fraction was affected by microbial activity. Hence, these δ18Op values likely reflected the oxygen isotopic values of the parent materials. The results suggested that phosphate oxygen isotope analyses could be an effective tool in order to trace phosphate sources, transformation processes, and its utilization by microorganisms in agricultural soils. 相似文献
375.
Combination of biochar amendment and phytoremediation for hydrocarbon removal in petroleum-contaminated soil 总被引:1,自引:0,他引:1
Tao Han Zhipeng Zhao Mark Bartlam Yingying Wang 《Environmental science and pollution research international》2016,23(21):21219-21228
Remediation of soils contaminated with petroleum is a challenging task. Four different bioremediation strategies, including natural attenuation, biochar amendment, phytoremediation with ryegrass, and a combination of biochar and ryegrass, were investigated with greenhouse pot experiments over a 90-day period. The results showed that planting ryegrass in soil can significantly improve the removal rate of total petroleum hydrocarbons (TPHs) and the number of microorganisms. Within TPHs, the removal rate of total n-alkanes (45.83 %) was higher than that of polycyclic aromatic hydrocarbons (30.34 %). The amendment of biochar did not result in significant improvement of TPH removal. In contrast, it showed a clear negative impact on the growth of ryegrass and the removal of TPHs by ryegrass. The removal rate of TPHs was significantly lower after the amendment of biochar. The results indicated that planting ryegrass is an effective remediation strategy, while the amendment of biochar may not be suitable for the phytoremediation of soil contaminated with petroleum hydrocarbons. 相似文献
376.
三峡库区重庆段土壤保持服务时空分布格局研究 总被引:4,自引:0,他引:4
土壤保持是生态系统服务与功能的重要组成,在防止土壤侵蚀、减少径流泥沙与农业面源污染等方面具有至关重要的作用。以对国家生态安全具有重要作用的土壤保持生态功能区——三峡库区重庆段为研究区域,研究得到了2000~2013年时间序列区域土壤保持服务"流量"结果,结果表明:(1)三峡库区重庆段多年平均土壤保持量为604.39 t/hm~2·a,沿长江干流自西向东逐渐增强,区域差异显著;(2)三峡库区的土壤保持服务存在明显的垂直分异特征,随着高程的增加,以300 m与900 m为节点,出现递减-递增-递减的分段规律,与人类活动存在明显的相关关系;(3)增加森林覆被面积是改善区域土壤保持、减少水土流失的重要举措。同时,在三峡库区开展坡改梯工程,减少坡耕地的数量能够有效控制区域水土流失; 相似文献
377.
以揭示中国南方丘陵地区河谷城市的空间演变过程和特征为目的,以上饶市城区为例,在遥感与GIS技术的支持下,对1988~2013年间上饶市城区城市用地的时空演变过程、特征及驱动影响因素进行了研究。结果表明,1988~2013年的25 a间,上饶市城区城市用地呈现出快速增长的态势,城市形态的演变具有明显的时空特征:时间序列上,不论扩展幅度还是扩展速度,2001~2013年间的值均高于1988~2001年间的值,前后两个时段的扩展特征呈现出明显的差异性;空间格局上,上饶市城区以老城区的中心广场为中心向四周扩展,先后经历了放射性扩展、组团式分散扩展两个阶段,同时呈现出明显的方向分异性,西南和西为其主要扩展方向,而其东南方向的扩展速度最为缓慢。自然环境中的地貌对上饶市城区城市用地的扩展起到很大的限制作用,经济社会的发展、政策规划等因素成为城市用地扩张与时空演化的外在驱动因素。 相似文献
378.
379.
提出了一种利用移动监测技术研究区域大气环境中PM2.5/PM10空间分布的方法,并在2004年12月进行了宁波市全市域PM2.5/PM10空间分布的研究。数据显示:相同路径所代表的地区PM2.5和PM10具有很好的相关性,多数路径上PM2.5与PM10数据的相关系数平方在0.95以上,而不同路径上PM2.5与PM10的比值不同。文中给出了宁波市PM2.5/PM10污染的空间分布图,直观地显示出PM2.5/PM10污染的空间分布情况,突出了污染的重点点位和地区。 相似文献
380.
Yu Ren Aijun Ding Tao Wang Xinhua Shen Jia Guo Jiamin Zhang Yan Wang Pengju Xu Xinfeng Wang Jian Gao Jeffrey L. Collett 《Atmospheric environment (Oxford, England : 1994)》2009,43(9):1702-1711
Measurement of ambient gas-phase total peroxides was performed at the summit of Mount Tai (Mt. Tai, 1534 m above sea level) in central-eastern China during March 22–April 24 and June 16–July 20, 2007. The hourly averaged concentration of peroxides was 0.17 ppbv (± 0.16 ppbv, maximum: 1.28 ppbv) and 0.55 ppbv (± 0.67 ppbv, maximum: 3.55 ppbv) in the spring and summer campaigns, respectively. The average concentration of peroxides at Mt. Tai, which is in a heavily polluted region, was much lower than hydrogen peroxide measurements made at some rural mountain sites, suggesting that significant removal processes took place in this region. An examination of diurnal variation and a correlation analysis suggest that these removal processes could include chemical suppression of peroxide production due to the scavenging of peroxy and hydroxy radicals by high NOx, wet removal by clouds/fogs rich in dissolved sulfur dioxide which reacts quickly with peroxides, and photolysis. These sinks competed with photochemical sources of peroxides, resulting in different mean concentrations and diurnal pattern of peroxides in the spring and summer. A principal component analysis was conducted to quantify the major processes that influenced the variation of peroxide concentrations. This analysis shows that in the spring photochemical production was an important source of peroxides, and the major sink was scavenging during upslope transport of polluted and humid air from the lower part of the planetary boundary layer (PBL) and wet removal by synoptic scale clouds. During the summer, highly polluted PBL air (with high NOx) was often associated with very low peroxides due to the chemical suppression of HO2 by high NOx and wet-removal by clouds/fogs in this sulfur-rich atmosphere, especially during the daytime. Higher concentrations of peroxides, which often appeared at mid-nighttime, were mainly associated with subsidence of air masses containing relatively lower concentrations of NOy. 相似文献