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Assessment of natural sepiolite on cadmium stabilization, microbial communities, and enzyme activities in acidic soil 总被引:4,自引:0,他引:4
Yuebing Sun Guohong Sun Yingming Xu Lin Wang Xuefeng Liang Dasong Lin Fazhi Hu 《Environmental science and pollution research international》2013,20(5):3290-3299
A pot trial was conducted to assess the efficiency of sepiolite-induced cadmium (Cd) immobilization in ultisoils. Under Cd concentrations of 1.25, 2.5, and 5 mg?kg?1, the available Cd in the soil after the application of 1–10 % sepiolite decreased by a maximum of 44.4, 23.0, and 17.0 %, respectively, compared with no sepiolite treatments. The increase in the values of soil enzyme activities and microbial number proved that a certain metabolic recovery occurred after sepiolite treatment. The dry biomass of spinach (Spinacia oleracea) increased with increasing sepiolite concentration in the soil. However, the concentration (dry weight) of Cd in the spinach shoots decreased with the increase in sepiolite dose, with maximum reduction of 92.2, 90.0, and 84.9 %, respectively, compared with that of unamended soils. Under a Cd level of 1.25 mg?kg?1, the Cd concentration in the edible parts of spinach at 1 % sepiolite amendment was lower than 0.2 mg?kg?1 fresh weight, the maximum permissible concentration (MPC) of Cd in vegetable. Even at higher Cd concentrations (2.5 and 5 mg?kg?1), safe spinach was produced when the sepiolite treatment was up to 5 %. The results showed that sepiolite-assisted remediation could potentially succeed on a field scale by decreasing Cd entry into the food chain. 相似文献
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Wang H He M Lin C Quan X Guo W Yang Z 《Environmental monitoring and assessment》2007,133(1-3):231-242
Surface sediment samples from 12 sites of the three selected rivers in Daliaohe River watershed (Hunhe River, Taizihe River
and Daliaohe River) were analyzed with the objective of establishing sources and hazard of the organochlorinae pesticides
(OCPs) and polychlorinated biphenyl (PCBs) in surface sediments. The total concentrations of OCPs varied from 3.06 to 23.24
ng g−1. ∑HCH (α-HCH, β-HCH, δ-HCH, γ-HCH), ∑DDT (p, p′-DDE, p, p′-DDD, o, p′-DDT, p, p′-DDT) and ∑Cyclodiene (Heptachlor, Aldrin,
Heptachlor epoxide, Dieldrin, Endrin) ranged from 1.86 to 21.48, 0.5 to 2.81 and 0.56 to 1.53 ng g−1, respectively. Results of OCPs also illustrate that the most dominant pollutants among the OCPs was ∑HCH, and γ-HCH was the
most dominant isomer in HCH, which was evidence of recent input of lindane. It possibly came from the runoff of polluted soils
and long-scale transportation. Total PCB concentrations ranged between 1.88 and 16.88 ng g−1. The peak concentrations of PCBs were found in sediments from station T5 and D3, which are in the vicinity of industrial
areas and ferry, respectively. These data show a moderate level of OCPs and PCBs contaminations compared to that in other
countries. 相似文献
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K. Bruce Jones Daniel T. Heggem Timothy G. Wade Anne C. Neale Donald W. Ebert Maliha S. Nash Megan H. Mehaffey Karl A. Hermann Anthony R. Selle Scott Augustine Iris A. Goodman Joel Pedersen David Bolgrien J. Max Viger Dean Chiang Cindy J. Lin Yehong Zhong Joan Baker Rick D. Van Remortel 《Environmental monitoring and assessment》2000,64(1):227-245
The Environmental Monitoring and Assessment Program (EMAP) is proposing an ambitious agenda to assess the status of streams and estuaries in a 12-State area of the western United States by the end of 2003. Additionally, EMAP is proposing to access landscape conditions as they relate to stream and estuary conditions across the west. The goal of this landscape project is to develop a landscape model that can be used to identify the relative risks of streams and estuaries to potential declines due to watershed-scale, landscape conditions across the west. To do so, requires an understanding of quantitative relationships between landscape composition and pattern metrics and parameters of stream and estuary conditions. This paper describes a strategic approach for evaluating the degree to which landscape composition and pattern influence stream and estuary condition, and the development and implementation of a spatially-distributed, landscape analysis approach. 相似文献
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以重点水力发电厂和大中型水库为主要考量,并兼顾地形地貌和中小河流的分布特征,将广西划分为23个电网流域,研究了基于非线性的神经网络电网流域面雨量预报方法。以5-6月龙滩近库区、龙江流域等6个电网流域为例,利用遗传算法优化BP神经网络的连接权和网络结构,建立了各电网流域的遗传-神经网络电网流域面雨量预报模型。对独立样本的预报结果表明,基于遗传-神经网络的电网流域面雨量预报模型的预报能力要优于传统的逐步回归预报模型,也明显优于日本、德国数值模式预报产品所换算成的电网流域面雨量预报,并与气象部门同期制作的综合面雨量预报产品能力相当,因而,遗传-神经网络面雨量集合预报模型有较好的业务应用前景。 相似文献