普通小球藻对复合重金属镉和铬的生物吸附及影响因素

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

摘要:

[背景] 微藻对重金属具有极强的耐受性，而且有较高的吸附率，是一种优良的生物吸附剂。[目的] 探究环境因素对小球藻吸附镉离子（Cd²⁺）和铬离子（Cr³⁺）的影响。[方法] 以普通小球藻（Chlorella vulgaris）在不同条件下对重金属离子的吸附率为基准，利用CdCl₂·2H₂O和CrCl₃·7H₂O提供重金属离子，根据不同处理下小球藻吸附率的变化情况探讨重金属离子浓度、pH和温度等环境因素对普通小球藻吸附Cd²⁺和Cr³⁺的影响。[结果] 在温度为30 ℃、pH值为5.5、Cd²⁺和Cr³⁺浓度分别为0.4 mg/L和4.0 mg/L及生物量为0.59 g/L的条件下，普通小球藻对复合Cd²⁺和Cr³⁺吸附率达到最大，吸附率分别达到84.5%和75.2%，同时发现普通小球藻对Cd²⁺的吸附率大于Cr³⁺。[结论] 小球藻对Cd²⁺和Cr³⁺的吸附受环境因素的影响，而且对不同的重金属具有一定的选择性。

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.