硅胶固定的褐藻渣对重金属Cu^(2+)吸附特征研究

Biosorption of Cu^(2+) by silica-gel-immobilized brown algae residue

褐藻渣是褐藻工业产生的固体废弃物,直接排放到环境中容易破坏水体生态平衡。本研究用硅胶固定的褐藻渣吸附重金属Cu2+,并对其吸附特征进行了检测。结果表明,吸附pH、Cu2+初始浓度以及吸附时间对吸附过程均有很大的影响。该吸附材料对初始浓度在2.0 mmol/L以下的Cu2+溶液吸附率可达85%,25℃时最大吸附容量在0.7～0.8 mmol/g之间;其吸附等温线符合Langmuir、Dubimim-Radushkevich方程,基本符合Freundlich方程;吸附动力学过程符合伪二级动力学模型,说明吸附限速步骤是化学吸附过程;实验结果表明硅胶固定的褐藻渣可以用于吸附Cu2+,其成本低廉,选择性好。

Algal residues,solid wastes in brown algae industrial production,can destroy ecological balance if they are discharged directly into natural waters.We investigated the biosorption characteristics of Cu2＋ by silica-gel-immobilized algal residues.The experimental data show that pH,initial Cu2＋ concentrations,and contact time have significant impact on biosorption process.The removal of Cu2＋ could reach about 85% when initial Cu2＋ concentration was below 2mmol/L,and the maximum adsorption capacities was around 0.7～0.8mmol/g at 25 °C.We also fit our equilibrium data with Langmuir,Freundlich or Dubinin-Radushkevich isotherm models.Kinetic features of Cu2＋ biosorption were modeled by pseudo first-order and pseudo second-order equations.The results indicate that the silica-gel-immobilized algal residue is low-cost,selective,easily regenerated,and of improved mechanical strength,and can be used for remove heavy metals from wastewater.