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991.
改性生物炭材料对稻田原状和外源镉污染土钝化效应 总被引:17,自引:1,他引:16
为研究改性处理后的生物炭对镉污染土壤钝化效应,以油菜秸秆制备的生物炭(BC)为原材料,通过不同处理(HNO_3氧化、NaOH碱化、KMnO_4浸渍、FeCl_3浸渍)制备改性炭材料,在室内连续培养试验中,分析了其对原土/外源镉污染土壤的钝化效应.结果表明,原炭及改性生物炭均降低了原状土壤有效态镉含量,其中Na OH和KMnO_4改性的炭材料钝化作用超过50%;在外源污染土壤中,NaOH、KMnO_4、FeCl_3改性炭材料均降低了土壤有效态镉含量,以添加10%的BC-KMnO_4较佳,降低作用超30%,HNO3改性炭却活化了3.8%~24.5%的土壤有效态镉.10%BC-KMnO_4显著降低原状土壤中可交换态镉含量达65.1%,而BC-HNO_3在外源污染土壤中活化可交换态镉含量高达20.2%.原炭及改性生物炭均增加了土壤中有机碳、盐基离子含量;原炭及NaOH、KMnO_4改性生物炭提高了土壤pH,HNO_3改性炭则降低了土壤p H;原状土中有效态镉含量与pH、交换性钠离子含量呈显著负相关,外源镉污染土中有效态镉含量则与pH、有机碳、交换性镁、钾、钠离子含量呈显著负相关.KMnO_4改性生物炭显著提高土壤pH,增加土壤有机碳和盐基离子含量,降低土壤镉活性形态含量,可作为优选的原位钝化修复材料,而HNO_3改性生物炭显著降低了土壤pH,提高了土壤有效态和可交换态镉含量,具有促进土壤镉生物有效性的风险. 相似文献
992.
China has experienced considerable urbanization in the past 60 years,especially since the implementation of the Economic Reform and Opening-up Policy in 1978.In 1949,there were only 132 cities with an urban population of 27.4 million,while in 2008 China had 652 cities with a total urban population of 606 million.Such urbanization is attributed to the boost in the number of cities and the urban population.Urban expansion enhanced geographic inequality between the three major regions in China.Compared with the eastern and central regions,western China only has 19%of the total cities and 18%of the urban population.The urbanization rate was 37.2%for the western region in 2008,while it reached 53.3%for the eastern regions and 45.3%for central China.Using a geographic information system(GIS)and statistical analyses,this study aims at explaining the structure and spatial development of urbanization,and highlighting the current issues of urban inequality in western China during the past two decades.The paper drew following conclusions:(1)Urbanization disparities between eastern and western China have become increasingly obvious,but seem to be evolving slowly since the establishment of the government’s Western Development Priority Policy in 2000.(2)Cities of various sizes were expanded in western China,and the main factors affecting the urbanization are population numbers and density,government investment and geographic conditions.(3)Current patterns of urbanization in the western region are distributed unevenly between provinces. 相似文献
993.
Abstract The natural supply of land resources is limited, but the economic supply may change along with social and economic development, and its size is decided bye nature and social and economic body conditions. When the supplying ability of land resources threatens the development of society and the conflict between people and land becomes tense, it forced people to improve land utilization and to increase the effective supply of land resources. The paper made an overall consideration on the characteristics of the irrigated farming and the frail ecological environment in Fuhai County, Altay Area, Xinjiang Uigur Autonomous Region and explored land arrangement planning as well as water resource planning and environmental protection. The paper evaluated natural resources, land utilization and water resource of the case study areas and focused on the spatio-temporal balance between the utilization of water and land resources. In the end the paper a feasible plan was made out for the land arrangement project. 相似文献
994.
Abstract It is difficult to realize the transformation from traditional economy industrial system to circular economy industrial system. Regarding primary raw materials as the indicators, the industrial system has been specified according to the divergence among the indicators and the circular utilization modes. In comparison with the association among industrial systems, the relationship among industrial sub-systems is named as industrial cross-linking in this paper. The industrial system which could completely utilize and recycle the indicators should be increased and strengthened, and the circular economy industrial system with complete industrial association and industrial cross-linking should also be constructed. Taking the development of circular agricultural system basing on the traditional agricultural system as an example, the traditional agricultural products are regarded as the indicators which have been divided into foodstuff and crop straws which are used to produce food and articles for use, like fertilizer, energy and papers etc. The way to construct the circular agricultural industrial system is to increase the industrial systems that could utilize the products generated from crop straws, feces and other castoffs and transform the wastewater and other trucks into environmental friendly products. It has also been pointed out that the construction of circular economy industrial system is conducive to the foundation of circular industrial economics and the establishment of the construction layout of circular economy and the application schemes. Suggestions to the theoretical and practical work of the next step have also been brought forward in this paper. 相似文献
995.
Abstract Since the reform and opening up, China’s export trade has maintained a rapid growth; meanwhile, China’s energy consumption has been increasing sharply. “High export and high energy consumption” has become the feature of China’s trade and economic development. In this paper, based on the input–output analysis approach, the authors have conducted an empirical study on the export trade and energy consumption of 21 trade industrial sectors. The results show that, China is a big net exporter of embodied energy. Assuming that the export growth rate of embodied energy maintains to be about 23.6%, the average annual growth rate of the past 32 years, and based on the input–output data of 2005, by 2030 China’s net export of embodied energy would be over eight times more than the aggregate energy production, which is obviously infeasible. As a country of very low per capita energy, China must change its export pattern, encourage or restrain the export of different industrial sectors according to their energy consumption intensity, and promote structural change of energy– efficient exported products, so as to achieve the sustainable development. Accordingly, the authors put forward some suggestions. 相似文献
996.
Abstract Suburbanization in large cities is an important phenomenon in the process of urbanization development in China in recent decades, which plays a very important role in promoting city development, whereas some side effects on the eco-environment appeared at the same time. This paper, taking Xi’an City in China as a case study site, analyzed the features of population suburbanization and industry suburbanization and pointed out the impacts of suburbanization on urban eco-environment. Based on the research, suggestions of countermeasures for urban planning and municipal management of Xi’an City in protecting urban eco-environment and conserving natural ecology were put forward in the end. 相似文献
997.
Cheng Yuan Cao Xu-bing Liu Jiu-meng Zhu Shengqiang Wang Siyu Yu Qin-qin Zhang Hongliang Zhang Qiang He Ke-bin 《Environmental Chemistry Letters》2022,20(5):2745-2750
Environmental Chemistry Letters - Heterogeneous reactions involving aerosol water, i.e., haze chemistry, are responsible for high aerosol concentrations observed during severe haze events in... 相似文献
998.
Rong Cheng Yingying Zhang Tao Zhang Feng Hou Xiaoxin Cao Lei Shi Peiwen Jiang Xiang Zheng Jianlong Wang 《Frontiers of Environmental Science & Engineering》2022,16(8):108
999.
Li Changlian Ju Liangliang Yang Mei Zhang Qi Sun Shu Cao Jiyu Ding Rui 《Environmental science and pollution research international》2022,29(4):5144-5152
Environmental Science and Pollution Research - Effects of prenatal ambient air pollution exposure could increase the risk of adverse pregnancy outcomes, which have been well documented by various... 相似文献
1000.
Wu Shuxuan Yang Yu Deng Sheng Cao Huali Liu Yunyan Yang Tianxue Wu Daishe Wang Chuqiao Ma Zhifei 《Environmental science and pollution research international》2022,29(23):34174-34185
Environmental Science and Pollution Research - In this study, a new straw-iron composite material (ST@Fe) was synthesized through impregnation and freeze-drying process for persulfate (PS)... 相似文献