Biosorption of Cd2+ and Cr3+ by Chlorella vulgaris and its influencing factors

Abstract:

[Background] Microalgae are resistant to heavy metals and have high adsorption rates, which can serve as an excellent biosorbent. [Objective] to explore the influences of environmental factors on the adsorption of Cd²⁺ and Cr³⁺ by Chlorella vulgaris. [Methods] Using CdCl₂·2H₂O and CrCl₃·7H₂O to provide heavy metal ions, we explored the influences of environmental factors such as the concentrations of heavy metal ions, pH, and temperature on the adsorption of Cd²⁺ and Cr³⁺ by C. vulgaris. [Results] At 30℃, pH 5.5, Cd²⁺ concentration of 0.4 mg/L, Cr³⁺ concentration of 4.0 mg/L, and C. vulgaris biomass of 0.59 g/L, the adsorption rates of Cd²⁺ and Cr³⁺ by C. vulgaris reached the maximums of 84.5% and 75.2%, respectively. The adsorption rate of C.vulgaris to Cd²⁺ was greater than that to Cr³⁺. [Conclusion] The adsorption of C. vulgaris to Cd²⁺ and Cr³⁺ is affected by environmental factors and C. vulgaris has certain preference to different heavy metals.

Key words:biosorption;Chlorella vulgaris;cadmium ion;chromium ion