YANG Jinlian, XING Ying, DANG Yaqin
( School of Chemistry and Materials Science, Guizhou Normal University, Guiyang 550025, China)
Abstract:Soil mercury ( Hg) contamination in the Wanshan Hg mining area in Guizhou province has led to excessive Hg levels in rice, adversely affecting food security in the Hg-contaminated areas. Biochar has a great potential to be used in remediation of heavy metal-contaminated soils and fighting against climatic change. Pot experiments were conducted to study the effect of application of rice husk biochar on mercury accumulation in different rice varieties ( Lianjing 15 and Jinjing 818) . The results reveal 1) Biochar application increased the biomass of rice plants; 2) The contents of soluble and exchangeable Hg in the biochar-treated soils decreased by 25. 92%-44. 09% as relative to the control, indicating a decrease of soil Hg bioavailability; 3) Compared with the control, the THg contents in the roots and polished rice of Lianjing 15 from the biochar treatments decreased by 26. 60%-31. 87% and 16. 68%-27. 85%, respectively. In comparison, no significant change in Hg contents in the tissues of Jinjing 818 from the biochar treatments as relative to the control. Accordingly, biochar amendment can effectively reduce soil Hg bioavailability as well as the accumulation of Hg in Lianjing 15 and therefore has high application potentials in the remediation of Hg-polluted paddy fields.
Key words:biochar; remediation; rice; mercury
EARTH AND ENVIRONMENT Vol. 51, No. 5, Tot No.355 2023
