Effects of Cation Exchange Capacity and Dissolved Organic Matter of Soil Amendments on Chemical Forms of Heavy Metals in Soils

• Published in: Nōgyō Nōson Kōgakkai ronbunshū Vol. 90; no. 1; pp. I_123 - I_130
• Main Authors: SAKURAI, Shinji, HORINO, Haruhiko, NAKAGIRI, Takao, MATSUO, Naho, NAKAMURA, Kimihito
• Format: Journal Article
• Language: Japanese
• Published: Tokyo The Japanese Society of Irrigation, Drainage and Rural Engineering 2022; 公益社団法人 農業農村工学会; Japan Science and Technology Agency
• Subjects: Agricultural land; Agricultural pollution; Cadmium; Cation exchange; Cation exchange capacity; Cation exchanging; Cations; Cattle manure; Composting; Copper; Dissolved organic matter; Dune sand; Exchange capacity; Farmyard manure; Heavy metal; Heavy metals; Immobilization; Manures; Metals; Organic amendment; Poultry manure; Rice straw; Soil; Soil amendment; Soil chemistry; Soil contamination; Soil organic matter; Soils; Uptake; 不動化; 有機質土壌改良資材; 水溶性有機物; 重金属; 陽イオン交換容量
• ISSN: 1882-2789; 1884-7242
• DOI: 10.11408/jsidre.90.I_123

Engineering and biological removal techniques of heavy metals in contaminated farmlands are sometimes unfeasible because of high cost and low efficiency on a large scale. Thus, the immobilization of metals in soils to prevent toxic metal uptake into crops using organic amendments has gained prominence. However, it is unclear which property of organic amendments influences heavy metal immobilization. We observed the chemical forms of Cu, Cd, and Pb through soil batch tests to elucidate the factors of immobilization using cow manure, poultry manure, and rice straw, including composting for 1 or 3 months (CM, PM, RS0, RS1, and RS3, respectively). The results from the experiments showed that CM had a high immobilization effect due to high cation exchange capacity and the mechanism of immobilization varies according to heavy metals. Furthermore, PM can promote the mobility of the three heavy metals, likely due to the heavy metal and dissolved organic matter complex. Based on the chemical forms, it is determined that composting promotes the immobilization effect of Cu in dune sand.