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该文根据某柴油污染场地调查和污染物检测结果,利用GMS中MODFLOW和SEAM3D模块建立研究区地下水流模型和典型非水相液体(NAPL)苯、甲苯及乙苯的运移模型研究了NAPL的运移规律,模型中考虑了对流-弥散、溶解、吸附和微生物降解等过程。研究结果显示,NAPL污染羽在100 d内运移较快,呈中心向四周均匀扩散趋势,随后逐渐沿地下水流向扩散,甲苯的污染羽面积大于苯和乙苯。敏感性分析表明,组分质量分数、溶解速率和Fe(Ⅲ)初始浓度是影响NAPL运移的关键因素。组分质量分数越大,其在地下水中的平衡浓度越高;溶解速率主要影响NAPL到达平衡的时间,溶解速率越大,到达平衡的时间越短;Fe(Ⅲ)初始浓度主要影响甲苯的微生物降解过程,Fe(Ⅲ)初始浓度越高,微生物降解作用越强,但对于苯和乙苯,微生物降解几乎不受Fe(Ⅲ)初始浓度的影响。该研究可为场地污染范围的确定、风险管控和修复提供科学依据。 相似文献
73.
为了应对日趋严苛的废水TN排放标准要求,试验采用溴百里酚蓝(BTB)培养基,从某煤化工废水处理厂反硝化缺氧池活性污泥中,经多次分离、纯化获得了一株高效兼性厌氧反硝化菌株HK13.通过形态观察及16S rRNA基因序列分析,菌株HK13被鉴定为施氏假单胞菌属(Pseudomonas stutzeri).在此基础上,利用含硝酸盐模拟废水,探讨了碳源类型、C/N(碳氮比)、初始pH、溶解氧(以不同摇床转速表征不同浓度的溶解氧)和培养温度对菌株HK13反硝化脱氮能力的影响,确定了该菌株的最优生长条件和最大脱氮效率.结果表明:(1)菌株HK13最适反硝化脱氮条件为以柠檬酸钠碳源,C/N 8,培养温度35℃,初始pH 8~10,摇床转速100 r/min.(2)初始ρ(NO3--N)为106.67 mg/L下,反应12 h后菌株HK13对TN的去除率可达92.62%;反应9~12 h时,该菌株的脱氮速率最高,可达20.03 mg/(L·h),其16 h的脱氮率在98%以上,且无亚硝酸盐积累.(3)菌株HK13适宜生长的温度和pH范围广泛,分别为20~40... 相似文献
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Chun Chen Yuzheng Wang Yuanyuan Zhang Xiaoxiu Lun Chengtang Liu Yujing Mu Chenglong Zhang Pengfei Liu Chaoyang Xue Min Song Can Ye Junfeng Liu 《环境科学学报(英文版)》2019,31(6):316-326
The efficient maintenance of the activity of excised branches is the powerful guarantee to accurately determine gas exchange flux between the detached branches of tall trees and the atmosphere. In this study, the net photosynthetic rate(NPR) of the excised branches and branches in situ were measured simultaneously by using two photosynthetic instruments to characterize the activity of the excised branches of Phyllostachys nigra. The ratio of normalized NPR of excised branches to NPR in situ was used to assess the photosynthetic activity of detached branches. Based on photosynthetic activity, an optimal hydroponics protocol for maintaining activity of excised P. nigra branches was presented:1/8 times the concentration of Gamborg B5 vitamin mixture with p H = 6. Under the best cultivation protocol, photosynthetic activity of excised P. nigra branches could be maintained more than 90% within 6 hr in the light intensity range of 200–2000 μmol/(m2·sec) and temperature range of 13.4–28.7°C. The nitrogen dioxide(NO2) flux differences between in situ and in vitro branches and the atmosphere were compared using double dynamic chambers.Based on the maintenance method of excised branches, the NO2 exchange flux between the excised P. nigra branches and the atmosphere(from-1.01 to-2.72 nmol/(m2·sec) was basically consistent with between the branches in situ and the atmosphere(from-1.12 to-3.16 nmol/(m2 sec)) within 6 hr. Therefore, this study provided a feasible protocol for in vitro measurement of gas exchange between tall trees and the atmosphere for a period of time. 相似文献
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Lugu lake is an alpine lake in Yunnan Province in western China. It is famous for its beautiful scenery and the special culture of Mosuo people in this area. The lake is becoming contaminated and eutrophicated because of the huge number of visitors and improvements in agriculture during the last decade. This paper uses the water quality index (WQI) as an indicator to describe trends in contamination of Lugu Lake from 1995 to 2004 and analyses several parameters to determine the causes and consequences of contamination. We found that the dominant cause was pollution from tourism and suggest some feasible measures to prevent further deterioration of the lake water quality. 相似文献
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动用多指标综合排序的双基点法,建立了环境治理工程评标的数学模型。应用实例表明,该模型可以为环境治理工程评标提供客观、合理的方法。 相似文献
80.
Jiangnan Tian Ayobami Matthew Olajuyin Tingzhen Mu Maohua Yang Jianmin Xing 《Environmental science and pollution research international》2016,23(12):11574-11583
The electro-Fenton (EF) process treatment of 0.1-M (rhodamine B) RhB solution was studied with different graphite cathode materials, and graphite felt (GF) was selected as a promising material in further investigation. Then, the degradation performances of gas diffusion electrode (GDE) and graphite felt (GF) were compared, and GDE was confirmed to be more efficient in RhB removal. The operational parameters such as Fe2+ dosage and current density were optimized, and comparison among different modified methods—polytetrafluoroethylene-carbon black (PTFE-CB), polytetrafluoroethylene-carbon nanotube (PTFE-CNT), electrodeposition-CB, and electrodeposition-CNT—showed 98.49 % RhB removal by PTFE-CB-modified cathode in 0.05 M Na2SO4 at a current density of 50 A/m2 and an air flow rate of 1 L/min after 20 min. Meanwhile, after cathode modified by PTFE-CB, the mineralization efficiency and mineralization current efficiency performed absolutely better than the pristine one. Cyclic voltammograms, SEM images, contact angles, and BET surface area were carried out to demonstrate stronger current responses and higher hydrophilicity of GF after modified. The value of biochemical oxygen demand/chemical oxygen demand (BOD5/COD) increased from 0.049 to 0.331 after 90-min treatment, suggesting the solution was biodegradable, and the modified cathode was confirmed to be stable after ten circle runs. Finally, a proposed degradation pathway of RhB was put forward. 相似文献