Variations in the environmental characteristics of groundwater slightly contaminated with petroleum: effects of enhanced bioremediation in northeast China     

Yuling Zhang  Hong Qian  Jiali Wang  Chaoqun Si  Zhiyu Chen  Jiangyan Dang  Zhenyi Zhang 《Environmental Earth Sciences》2017,76(2):90

The objective of this paper was to investigate a petroleum-contaminated groundwater site in northeast China. Based on the monitoring and analysis of environmental characteristics of groundwater slightly contaminated with petroleum, microbes were added into the petroleum-contaminated groundwater via single-well and multiple-well models to enhance bioremediation. The effect of enhanced bioremediation was monitored and analyzed, and variations in the environmental characteristics of groundwater containing total petroleum hydrocarbons (TPH) were identified to provide a scientific basis for controlling and remediating petroleum-contaminated groundwater. Findings confirmed that this site was slightly contaminated and TPH levels exhibited a slight decreasing trend. After enhanced remediation, the microbial degradation effect was large, and the TPH concentration significantly reduced. In particular, near the wells treated by bioremediation, the amounts of electron acceptors, such as NO₃ ^?, Fe³⁺, and SO₄ ^2?, markedly decreased. The product of the microbial degradation process, HCO₃ ^?, gradually increased in the treated wells. Activities of the enzyme catechol 1, 2-dioxygenase decreased, while those of catalase increased. Reductions in pH, from 7.4 to 6.1, were recorded, and the groundwater environment became further deoxidized.  相似文献   

两种尺寸蒸渗计测量实际蒸散差异性试验研究     

杨启国  杨兴国  张旭东  马鹏里  刘宏谊  李晓峰  党选发  孔令旺 《中国沙漠》2017,37(1):167-174

利用试验资料,对蒸散面积2 m²和4 m²两种尺寸蒸渗计测量蒸散量的差异及原因进行了研究。结果表明：2 m²蒸渗计与4 m²蒸渗计所测蒸散量具有很好的一致性,但2 m²蒸渗计所测蒸散量总体要略偏大,日蒸散量平均偏大4%,月蒸散量平均偏大10%,年蒸散量相对偏大5%;典型天气条件下,2 m²蒸渗计和4 m²蒸渗计所测蒸散量的日变化过程基本相同,小时蒸散量的差异表现为晴天时白天显著偏大、夜晚略有偏小,阴天时白天略偏大、夜晚较接近,雨天时白天、夜晚均非常接近的特征。晴天和阴天时,2 m²蒸渗计比4 m²蒸渗计测量日蒸散量分别偏大1.78 mm和0.12 mm,雨天时偏小0.11 mm;2 m²蒸渗计比4 m²蒸渗计测量蒸散量总体偏大的原因,主要是2 m²蒸渗计土壤温度显著高于4 m²蒸渗计和建造时间不同导致土体内部土壤湿度产生差异。  相似文献   

GALILEO�걸��ϵͳ��XPL�㷨�о�     

谷守周  秘金钟  党亚民 《大地测量与地球动力学》2010,30(2):104-108

????XPL????Ч?????????HPL??VPL??????????????????м?????????????????????HPL??VPL??????????????HPL??VPL?????????С??9 m??12 m?????????12 m??20 m?????????????????????????????????????  相似文献   

RC框架结构地震倒塌易损性分析的实用方法     

党王桢  梁兴文 《震灾防御技术》2015,10(4):986-995

基于增量动力分析(IDA)的倒塌易损性分析方法是评估建筑结构抗地震倒塌能力的精细方法,但分析过程比较繁杂且非常费时。为了较快地评估建筑结构的抗地震倒塌能力,首先利用静力非线性(pushover)分析,获得结构倒塌能力的初步估计值aS*,然后将每个地面运动记录调整到aS*,对结构进行动力时程分析,记录结构的动力时程反应,利用IDA的思想得到结构的中值数倒塌谱强度?CTS。该方法与传统的增量动力分析方法相比较,可提高计算效率,计算精度也满足要求。  相似文献   

Remediation of soil co-contaminated with pyrene and cadmium by growing maize (Zea mays L.)     

H. Zhang  Z. Dang Ph.D.  L. C. Zheng  X. Y. Yi Ph.D. 《International Journal of Environmental Science and Technology》2009,6(2):249-258

Sites co-contaminated with organic and metal pollutants are common and considered to be a more complex problem as the two components often causes a synergistic effect on cytotoxicity. Phytoremediation has been proposed as a cost-effective technology for treating heavy metal or organic contamination and may be suitable for remediation of co-contaminated soil. This study investigated the concurrent removal of pyrene and cadmium in co-contaminated soil by growing maize in a pot experiment. At the end of 60 day culture, pyrene in spiked soil diminished significantly, accounting for 21–31 % of the initial extractable concentration in unplanted soil and 12–27 % in planted soil. With the increment of cadmium level, the residual pyrene both in unplanted and planted soil tended to increase. Although the presence of cadmium increased the accumulation of pyrene in maize, plant accumulation only account for less than 0.30 % of the total amount of the dissipated pyrene in vegetated soils. It implied that plant-promoted microbial biodegradation was the predominant contribution to the plant-enhanced dissipation of pyrene in co-contaminated soil. Unlike pyrene, heavy metal cadmium cannot be degraded. It was observed that maize can concurrently removed about on the average 0.70 % of the total cadmium amount in soil by plant uptake, but cadmium phytoextraction would be inhibited under contamination of pyrene. Maize CT38 can normally grow in the co-contaminated soil with high level cadmium and pyrene and can effectively remedy the sites co-contaminated with these two types of contamination, which suggest the possibility of simultaneous phytoremediation of two different contaminant types.  相似文献   

区域持续农业的景观生态研究   总被引：9，自引：1，他引：8  

韩荡  王仰麟 《干旱区地理》1999,22(3):1-8

从提出背景,概念内涵,本质特性以及实践内容来看,持续农业具有鲜明的生态内涵,研究离不开生态学的指导;从系统主体,出发点、尺度、动态来看,区域持续农业在更大程度上属于景观生态学的研究范畴,因此 生态学可作为区域持续珠理论基础,而主观生态学应用方向的景观生态规划便可实现区域持续农业的空间途径,最后,文章以中国北方农牧过渡北山地的景观利用方向进行案例实践。  相似文献   

切伦科夫线辐射的基本公式     

刘当波  靳光学 《天文学报》1999,40(4):382-393

在８０ 年代初,尤峻汉和程富华从理论上证实,当相对论电子在稠密气体中运动时,切伦科夫效应将产生宽的、轮廓明显不对称的原子或分子发射线．此后这一新的谱线发射机制被一系列实验所确证．尤峻汉等人又进一步给出了有关切伦科夫辐射的系列解析公式,但其有关谱轮廓和红移的结论只适用于极稠密的气体．由于这一线辐射机制在天体物理中的潜在重要性,在他们工作的基础上,进一步简化、推广、改进了原有的公式体系,并以天体物理学家熟悉的形式做出了更便于实际应用的表述  相似文献   

"亚太六号"卫星发射日气象保障及数值模拟分析     

江晓华  党建涛  杨亚琦 《高原山地气象研究》2005,25(4)

2005年4月11～12日西昌发射场遭遇了一次寒潮天气过程,而这正值"亚太六号"卫星预定的发射日.针对这一情况,发射中心气象部门利用多种探测手段,综合分析各类气象信息,采取逐步逼近的方式,在复杂条件下抓住了有利战机,准确预报出了此次寒潮过程及对场区的影响程度,圆满完成了气象保障任务.此外,利用相关资料对发射日资料进行了数值模拟,结果表明,MM5模式较好地模拟了本次天气过程中的降水、降温和增压过程.  相似文献   

Stochastic finite-fault ground motion simulation for the Mw 6.7 earthquake in Lushan,China     

Dang  Pengfei  Liu  Qifang 《Natural Hazards》2020,100(3):1215-1241

Natural Hazards - The Ya’an, Sichuan Mw 6.7 earthquake occurred on April 20, 2013. In this article, the stochastic finite-fault method (EXSIM) based on dynamic corner frequency, proposed by...  相似文献   

Simulation of the Jiuzhaigou,China, earthquake by stochastic finite-fault method based on variable stress drop     

Dang  Pengfei  Liu  Qifang  Song  Jian 《Natural Hazards》2020,103(2):2295-2321

Natural Hazards - An improved stochastic finite-fault method was used to simulate the Mw 6.6 earthquake that occurred on August 8, 2017, in Jiuzhaigou, Sichuan, China. A variation of the stochastic...  相似文献