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401.
随着新能源汽车工业的快速发展,废旧三元动力锂电池的量在不断地增加。三元动力锂电池中含有丰富的Co、Mn、Li和Ni资源,回收三元动力锂电池是防止环境污染和回收贵重金属的理想选择。利用抗坏血酸(C6H8O6)的酸性和还原性对废旧三元锂电池正极材料进行浸出,KMnO_4的强氧化性回收浸出液中的Co制备β-CoC_2O_4·2H_2O,采用浓度为1.3 mol·L~(-1)的C_6H_8O_6,在60℃的条件下对正极材料浸出20 min,向浸出夜中加入1 mol·L-1的H_2SO_4反应20 min后加入KMnO_4继续反应1 h,制得β-CoC_2O_4·2H_2O。实验结果表明,Co的回收率达91%,Li的浸出率可达96.4%,Mn和Ni完全浸出,可实现简单环保地浸出有价金属并回收Co。 相似文献
402.
采用半静态染毒方法,研究了单壁碳纳米管(SWCNT)和羟基化多壁碳纳米管(MCWNT-OH)对锦鲫抗氧化防御系统的影响。 结果表明,锦鲫经28d不同质量浓度的SWCNT和MWCNT-OH(0,10,100和1000μg/L)暴露后,暴露组14d鳃组织切片检查发现出现鳃动脉瘤、鳃细胞水肿、畸形生长等病理症状;然而在2种碳纳米管低浓度暴露下,锦鲫的肝脏切片没有观察到损伤,高浓度时肝脏有轻微空泡损伤。暴露期间锦鲫没有死亡,随着暴露天数的增加,2种碳纳米管都能对SOD和CAT酶产生抑制作用,高浓度组抑制明显,肝脏抗氧化系统受到损伤。指出,虽然碳纳米管的毒性较低,但其长期暴露对鱼类的影响仍需进一步关注。 相似文献
403.
Eco-Environmental Degradation in the Source Region of the Yellow River, Northeast Qinghai-Xizang Plateau 总被引:4,自引:0,他引:4
The Yellow River is the second longest river in China and the cradle of the Chinese civilization. The source region of the Yellow River is the most important water holding area for the Yellow River, about 49.2% of the whole runoff comes from this region. However, for the special location, it is a region with most fragile eco-environment in China as well. Eco-environmental degradation in the source region of the Yellow River has been a very serious ecological and socially economic problem. According to census data, historical documents and climatic information, during the last half century, especially the last 30 years, great changes have taken place in the eco-environment of this region. Such changes are mainly manifested in the temporal-spatial changes of water environment, deglaciation, permafrost reduction, vegetation degeneracy and desertification extent, which led to land capacity decreasing and river disconnecting. At present, desertification of the region is showing an accelerating tendency. This paper analyzes the present status of eco-environment degradation in this region supported by GIS and RS, as well as field investigation and indoor analysis, based on knowledge, multi-source data is gathered and the classification is worked out, deals with their natural and anthropogenic causes, and points out that in the last half century the desertification and environmental degradation of this region are mainly attributed to human activities under the background of regional climate changes. To halt further degradation of the environment of this region, great efforts should be made to use land resources rationally, develop advantages animal agriculture and protect the natural grassland. 相似文献
404.
Weyer PJ Smith BJ Feng ZF Kantamneni JR Riley DG 《Environmental monitoring and assessment》2006,116(1-3):81-90
Nitrate contamination of water sources is a concern where large amounts of nitrogen fertilizers are regularly applied to soils.
Ingested nitrate from dietary sources and drinking water can be converted to nitrite and ultimately to N-nitroso compounds,
many of which are known carcinogens. Epidemiologic studies of drinking water nitrate and cancer report mixed findings; a criticism
is the use of nitrate concentrations from retrospective drinking water data to assign exposure levels. Residential point-of-use
nitrate data are scarce; gaps in historical data for municipal supply finished water hamper exposure classification efforts.
We used generalized linear regression models to estimate and compare historical raw water and finished water nitrate levels
(1960s--1990s) in single source Iowa municipal supplies to determine whether raw water monitoring data could supplement finished
water data to improve exposure assessment. Comparison of raw water and finished water samples (same sampling date) showed
a significant difference in nitrate levels in municipalities using rivers; municipalities using other surface water or alluvial
groundwater had no difference in nitrate levels. A regional aggregation of alluvial groundwater municipalities was constructed
based on results from a previous study showing regional differences in nitrate contamination of private wells; results from
this analysis were mixed, dependent upon region and decade. These analyses demonstrate using historical raw water nitrate
monitoring data to supplement finished water data for exposure assessment is appropriate for individual Iowa municipal supplies
using alluvial groundwater, lakes or reservoirs. Using alluvial raw water data on a regional basis is dependent on region
and decade. 相似文献
405.
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407.
基于CA的城市形态扩展多解模拟——以北京市东部平原区情景分析为例 总被引:3,自引:0,他引:3
构建了一个基于人工神经网络的约束型城市扩展CA模型。利用该模型,预测了北京市东部平原区在3种情景规划之下的未来50年的城市形态,为不同的城市发展模式之间的比较分析奠定基础。然后以2024年的北京东部平原区模拟城市形态为基准,从自然生态功效、社会服务功效、经济利益功效3个方面对3种规划模式进行了情景分析,从而系统的比较了3种规划模式的复合生态功效,为城市规划决策提供有力的支持。 相似文献
408.
我国危险废物特性鉴别技术体系研究 总被引:7,自引:2,他引:5
详细深入地调查分析了国外危险废物鉴别技术体系的特点和适用条件,以及我国危险废物管理的特点.在借鉴国内外经验与教训的基础上,提出了我国危险废物特性鉴别的技术路线及危险废物鉴别的环境保护目标,建立了危险废物鉴别技术的方法学.在充分研究的基础上,编制完成了全新的<国家危险废物名录>和<危险废物鉴别标准>,以及相应的规范和方法标准.这些技术文件形成了我国独特、完整的危险废物鉴别技术体系,为全面开展危险废物无害化管理提供了有力的技术支持. 相似文献
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