Search

Copyright of Journal of Agro-Environment Science is the property of Journal of Agro-Environment Science Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Soil heavy metal pollution has become one of the hot environmental issues of global concern, and its treatment and remediation has become a major scientific and technological demand for social and economic development. Soil animal earthworm-plant remediation has become a new way to control soil heavy metal pollution. Based on a large number of documents at home and abroad, this paper expounds the important role of earthworms in phytoremediation of heavy metal contaminated soil from three aspects, including changing soil physical and chemical properties from earthworm activities to accelerate phytoremediation of heavy metals, promoting phytoremediation of heavy metals by earthworm and microbial interaction, change of heavy metal morphology by earthworm secretion and excrement to affect phytoremediation of heavy metals, so as to provide theoretical reference for subsequent related research. [ABSTRACT FROM AUTHOR]

This paper briefly describes the mechanism of phytoremediation, the advantages and the application of ornamental woody plants. Based on the article analysis, it is found that the concept of hyper accumulation has been emphasized too much in the study of phytoremediation, the usage of herbal hyper-accumulator plants can not last for a long period in field level as the economic benefits is fairly low. Thus, the outstand advantages of ornamental woody plants are outlined, such as more biomass, casier management, pollution remediation and improvement of cultural environments. Relevant studies of remediation by ornamental woody plants are focused on variety, absorption characteristics and resistance assessment. Conclusion: ornamental woody plants show strong resistance and significant ability of metal adsorption. Ornamental woody plants have great potential in remediation of heavy metal comminuted soil. In the future, the theory of resistance and absorption should be strengthened. Other studies are also important, such as expanding the types of ornamental woody remediation plants and screening out more economic and effective plants. As a result, more and more ornamental plants will be put into practice in remediation. [ABSTRACT FROM AUTHOR]

Most of the heavy metal-related deposits are distributed in watersheds of mountainous areas, and the enrichment of soil heavy metals were affected by both natural high background and anthropogenic source in the area. It is particularly important to formulate precaution countermeasures to accurately identify and quantify the source of soil heavy metal pollution in the ore-concentrating area. This paper studies the surface soil of a small basin in Beishan Reservoir which was rich in ores. Based on the evaluation of the heavy metal accumulation degree, the pollution sources identification and their contributions to soil heavy metals were studied by multiple methods including field investigation, multivariate statistical analysis, positive matrix factorization(PMF), spatial analysis, and other methods. Conclusively, the accumulated Cu and Cd in the top soil were higher than other heavy metals, the Cu and Cd average contents were 3.05, 3.47 times as high as the regional background value, and exceeded the soil risk screening values. About 10% of samples reached the level of moderate to severe enrichment. The heavy metal pollution sources in the topsoil were jointly affected by natural geological background, mining activities, and agricultural activities source. The contribution rates of mining activities to Cu and Cd are 68.92% and 56.31%, and natural geological backgrounds also contribute 21.05% and 38.35% to them. The natural source contributed most to As, Cr, and Ni, with contribution rates of 83.13%, 72.59%, and 78.76%, respectively. Hg mainly comes from agricultural activities, and its contribution rate was 81.79%. Zn and Pb were affected by both material migration and natural geological background. The reliability and rationality of the analytical results for the heavy metal pollution sources can be improved by the mutual verification of the combination using different methods. [ABSTRACT FROM AUTHOR]

Combined with the existing research, the research progress of biochar remediation of heavy metal pollution is reviewed. This paper focuses on the mechanism of biochar immobilization of heavy metals in soil, the effect of biochar on the absorption of heavy metals by plants, the research results of the application of biochar in field engineering, and the risks and shortcomings o£ biochar as a soil improver. Finally, it is hoped that on the premise of meeting safe production, the popularization of biochar should be promoted in agricultural production, rather than limited to scientific research. Start the life cycle assessment of biochar and establish a biochar life cycle database to provide a comprehensive and effective scientific basis for the future use of biochar. [ABSTRACT FROM AUTHOR]