LIU Chaoshu¹, MO Yafei¹, SUN Rongguo¹, ZHANG Yutao²

(1. School of Chemistry and Material, Guizhou Normal University, Guiyang 550025, China;
2. College of Resource and Environmental Engineering, Anshun University, Anshun Guizhou 561000, China)

Abstract: The adsorption kinetics and isotherm adsorption model of methylmercury (MeHg) in water by living, dead Aphanizomenon flosaquae and Microcystis aeruginosa were studied. The results showed that when the concentration of MeHg was 100 ng/L, for living and dead Aphanizomenon flosaquae, 99.2% and 90.9% of MeHg in water were adsorbed, respectively, and the respective equilibrium adsorption amounts were 9.9×10-2 ng/(108cells) and 9.1×10-2 ng/(108cells), respectively. For living and dead Microcystis aeruginosa, 98.5% and 94.0% of MeHg in water were adsorbed, respectively, and the respective equilibrium adsorption amounts were 9.9×10-2 ng/(108cells) and 9.4×10-2 ng/(108cells), respectively. The adsorption kinetics of MeHg by two algae were in accordance with the quasi-first-order and quasi-second-order kinetic models. The isotherm adsorptions of MeHg by living Aphanizomenon flosaquae and living and dead Microcystis aeruginosa were in accordance with the Freundlich isotherm adsorption model. The isotherm adsorption of MeHg by dead Aphanizomenon flosaquae was in accordance with the Langmuir isotherm adsorption model. The structure of algae cell was characterized and indicated that the adsorption of MeHg by living algae and dead algae showed a rapid biological adsorption process on the cell surface, while the living algae also showed a slow biological enrichment process, so the adsorption rate of MeHg by living algae was higher than that of dead algae.

Key words: Algae; MeHg; adsorption; kinetics; isotherm adsorption model

EARTH AND ENVIRONMENT Vol.48, No.4, Tot No.336, 2020, Page 518