Department of Environmental Sciences, Faculty of Life and Environmental Sciences, Prefectural University of Hiroshima, 562 Nanatsuka-Cho, Shobara City, Hiroshima, Japan.
Arch Environ Contam Toxicol. 2013 Feb;64(2):180-6. doi: 10.1007/s00244-012-9829-5. Epub 2012 Nov 29.
This study describes the decomposition of polychlorinated biphenyls (PCBs) in soil with dispersion mixtures of metallic calcium (Ca) and calcium oxide (CaO) at different temperatures. In these experiments, naturally moisturized and contaminated soil (1.0 g [31 ppm PCBs]), CaO (dried 2.0 wt%), and metallic Ca (0.01 g [0.25 mmol]) were introduced into a stainless steel pressure reactor under 0.1 MPa N(2) gas. The mixtures were stirred magnetically and heated at 260, 280, and 300 °C, respectively. Soil treatment with metallic Ca and CaO under various temperature conditions is extremely effective for degrading existing PCBs. Decomposition resulted from dechlorination (DC). Initial moisture in soil acted as a hydrogen source during stirring. Soil moisture can be beneficial for hydrodechlorination in the presence of metallic Ca and CaO. Furthermore, metallic Ca and CaO can greatly increase the number of collisions and mutual refinement. Treatment at 260, 280, and 300 °C combined with metallic Ca and CaO is effective for the decomposition (approximately 95 % DC) of PCBs in soil under natural moisture conditions.
本研究描述了在不同温度下，用金属钙 (Ca) 和氧化钙 (CaO) 的分散混合物在土壤中对多氯联苯 (PCBs) 的分解。在这些实验中，将自然湿润和污染的土壤（1.0g[31ppmPCBs]）、CaO（干燥 2.0wt%）和金属 Ca（0.01g[0.25mmol]）引入不锈钢压力反应器中，在 0.1MPaN2 气体下。混合物在磁力搅拌下分别在 260、280 和 300°C 下加热。在各种温度条件下，用金属 Ca 和 CaO 处理土壤对现有 PCB 的降解非常有效。分解是通过脱氯（DC）实现的。初始土壤湿度在搅拌过程中充当氢源。在存在金属 Ca 和 CaO 的情况下，土壤湿度有利于加氢脱氯。此外，金属 Ca 和 CaO 可以大大增加碰撞和相互细化的次数。在 260、280 和 300°C 下结合金属 Ca 和 CaO 的处理，对于自然湿度条件下土壤中 PCB 的分解（约 95%DC）是有效的。
