Research of the application of organic amendment on the amelioration of copper and nickel polluted soils

• Main Authors: Ni-Shan Tsai 蔡妮珊, 蔡妮珊
• Other Authors: 陳仁炫
• Format: Others
• Language: zh-TW
• Published: 2006
• Online Access: http://ndltd.ncl.edu.tw/handle/38190316923326761395

碩士 === 中興大學 === 土壤環境科學系所 === 94 === Acid washing and soil turnover and attenuation are two main means to remediate the heavy metal polluted soils in Taiwan, but both of them may reduce soil fertility status and effect the growth of the sequent crop. Organic amendments have been known to improve the fertility of soil as well as to reduce the bioavailability of heavy metal. Therefore, it is perhaps a feasible way to ameliorate the pollution of heavy metal and increase soil fertility by using organic amendments. However, the availability to reduce heavy metal bioavailability in the soil may vary with the characteristics of organic amendments, the evaluation should be done, and it is what the purpose of this study. Four kinds of organic amendments with different characteristics (soybean meal, peat, wasted mushroom culture medium and composted animal manure) and a organic chelator (diethylene triamine pentaacetate, DTPA) were selected in the study and were added into the artificial copper and nickel polluted soils at the rates of 2% dose (W/W) and 1% C (W/W). Samples incubated for 1 day, 4 and 12 weeks were evaluated for the effects of different amendments application on the bioavailability of copper or nickel in the soil. In addition, a column leaching experiment was conducted to investigate the influence of amendment composition on copper or nickel movement in the soil profile and evaluate the risk of groundwater pollution. Result showed that the application of DTPA increased the bioavailability of copper or nickel in the soil and induced the leaching out from the soil profile, hence might significantly cause the pollution of groundwater. In the experiment of copper polluted soil, the addition of composted animal manure increased soil pH and significantly increased the content of organic-bound copper, therefore, resulted in reducing copper bioavailability. In the experiment of nickel polluted soil, the application of soybean meal reduced the bioavailability of nickel in the soil significantly at 4 week incubation but rose again after 12 weeks incubation, and resulted in ameliorating unstable, therefore, composted animal manure had proved to be a better ameliorative amendment. Under the study condition, the copper or nickel content in leachate were below the allowable value of copper or nickel in groundwater with four organic amendments application, hence the risk of groundwater pollution was less, and the application of composted animal manure had the best result in reducing the bioavailability of copper or nickel in the soil profile. By the results of whole evaluation above, it is suggested that the application of composted animal manure has better capacity in ameliorating copper and nickel pollution and promoting soil fertility than other amendments. It is concluded that a high quality composted animal manure with low contents of salt and heavy metals is the best choose amendment for the amelioration of heavy metal polluted soils.