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431.
Christina N. Kranz Richard A. McLaughlin Aziz Amoozegar Joshua L. Heitman 《Journal of the American Water Resources Association》2023,59(5):1115-1127
There has been widespread interest in using compost to improve the hydrologic functions of degraded soils at construction sites for reducing runoff and increasing infiltration. The objective of this study was to determine the effects of compost amendment rate on saturated hydraulic conductivity (Ks) and water retention in order to identify target compost rates for enhancing soil hydrologic functions. Samples were prepared with three soil textures (sandy loam, silt loam, and sandy clay loam), amended with compost at 0%, 10%, 20%, 30%, 40%, and 50%. All soils were tested at a porosity of 0.5 m3/m3, and the sandy loam was further tested at high (0.55 m3/m3) and low (0.4 m3/m3) porosities. The Ks and water retention data were then used to model infiltration with HYDRUS-1D. With increasing compost amendment rate, Ks and water retention of the mixtures generally increased at the medium porosity level, with more compost needed in heavier soils. As porosity decreased in the sandy loam soil, the amount of compost needed to improve Ks rose from 20% to 50%. Water distribution in pore fractions (gravitational, plant-available, and unavailable water) depended on texture, with only the highest compost rates increasing plant-available water in one soil. Results suggest soil texture should be taken into consideration when choosing a compost rate in order to achieve soil improvement goals. Hydrologic benefits may be limited even at a high rate of compost amendment if soil is compacted. 相似文献
432.
芳烃羟化酶与鲫鱼组织富集多环芳烃和代谢释放的关系 总被引:3,自引:0,他引:3
为了解芳烃羟化酶与多环芳烃在鱼体内代谢的相互关系,揭示多环芳烃在生物体中的分布、迁移和转化规律,采用放射性同位素示踪方法,研究了多环芳烃14C-2,6-二甲基萘在鲫鱼鳃、肝、肌肉、胆、脂肪、肾等7种组织中的富集和释放;对鲫鱼各组织富集的多环芳烃释放与芳烃羟化酶(AHH)的相关性进行了分析。结果表明,鲫鱼7种组织均能对多环芳烃富集,不同组织表现出不同的富集水平和释放水平;多环芳烃在鱼体中的释放速度与芳烃羟化酶活力水平及其酶促产物呈负相关。 相似文献
433.
Microbial changes in rhizospheric soils contaminated with petroleum hydrocarbons after bioremediation 总被引:5,自引:0,他引:5
Effects of bioremediation on microbial communities jn soils contaminated with petroleum hydrocarbons are a scientific problem to be solved. Changes in dominate microbial species and the total amount of microorganisms including bacteria and fungi in rhizospheric soils after bioremediation were thus evaluated using field bioremediation experiments. The results showed that there were changed dominant microorganisms including ] ] bacterial strains which are mostly Gram positive bacteria and 6 fungal species which were identified. The total amount of microorganisms including bacteria and fungi increased after bioremediation of microbial agents combined with planting maize. On the contrary, fungi in rhizospheric soils were inhibited by adding microbial agents combined with planting soybean. 相似文献
434.
ASE萃取-SPE净化-HPLC法测定土壤中多环芳烃 总被引:6,自引:0,他引:6
建立了加速溶剂萃取-固相萃取净化-高效液相色谱测定土壤中16种多环芳烃的方法,优化了试验条件.方法线性关系良好,16种多环芳烃的检出限在0.412 ng/g~3.974 ng/g之间,空白加标试验的相对标准偏差在1.2%~12.7%之间,基质加标回收率在60.4%~126%之间.实际样品的测定结果表明该方法分离效果好,能够满足土壤分析的要求. 相似文献
435.
Wenchao Jiang Ping Tang Zhen Liu Huan He Qian Sui Shuguang Lyu 《Frontiers of Environmental Science & Engineering》2020,14(2):18
436.
437.
A collaborative study was performed on scallops (Chlamys farreri) exposed to 0.5, 3 and 10 microg/L benzo[a]pyrene (B[a]P) for 20 days. The levels of aryl hydrocarbon hydroxylase (AHH) activity, B[a]P accumulation and DNA strand break were assayed in the gill and digestive gland. Results showed that AHH activity and B[a]P accumulation were significantly related to B[a]P dose. AHH activity was induced and then became stable gradually. B[a]P accumulation increased first and showed an incoming plateau. DNA strand break levels in the 0.5 and 3 microg/L B[a]P groups remained high and significantly different from control values until day 6, followed by a reduction in the gill and no recovery in the digestive gland. The 10 microg/L B[a]P groups remained significantly lower than control until the end. These results suggested that the application of comprehensive indices may give information on the actual exposure of organisms to pollutants, and also information on toxic effects. 相似文献
438.
李伟华 《防灾减灾工程学报》2010,30(6)
用理想流体介质模拟水层、流体饱和多孔介质模拟饱和土地层,在理想流体介质与流体饱和多孔介质相连接边界的连续条件基础上,结合已有的对理想流体介质、流体饱和多孔介质进行动力反应分析的显式有限元方法,开考虑地层与结构的动力相互作用,建立了进行水与场地、结构耦合动力分析的方法。利用该方法对沉管隧道的地震响应进行了研究,重点分析了水深、地质条件等因素对沉管隧道地震反应的影响,并从中得出了一些可供相关人员进行沉管隧道抗震分析时参考的结论。 相似文献
439.
440.
苯和甲苯硝化及磺化反应热危险性分级研究 总被引:1,自引:1,他引:0
首先介绍了化工工艺热安全性的内涵,并从反应过程热危险性分析的方法学出发,介绍间隙、半间歇化学反应工艺热危险性分级研究的总体思路及方法。然后,围绕甲苯和苯的硝化、磺化反应,用全自动反应量热仪(RC1e)和加速度量热仪(ARC)测定其反应过程的绝热温升(△Tad)、目标反应所能达到的最高温度(TM)、分解反应最大速率到达时间(θD)等参数。运用风险评价指数矩阵法(方法1)和基于失控过程温度参数的热危险评估法(方法2)分别对其硝化和磺化反应过程的热危险性进行了分级评估。结果表明,这两种方法具有良好的一致性;给定工艺条件下甲苯和苯的一段硝化反应过程的热危险度等级较低;而磺化反应的热危险较高。尽管这两种方法还有一定的局限性,但对于间歇、半间歇合成工艺的本质安全化设计、工艺热危险性的评估具有重要的参考价值和实用意义。 相似文献