为了研究辉光放电电解等离子体(GDEP)的放电参数对所合成的纤维素基水凝胶材料吸附重金属离子性能的影响,采用不同的放电电压和放电时间制备了一系列纤维素基水凝胶材料,通过浸泡、恒温震荡、乙二胺四乙酸(EDTA)滴定实验检测了水凝胶对重金属离子的吸附能力,利用准2级动力学模型和朗缪尔(Langmuir)等温方程描述了不同放电参数下制得的水凝胶吸附重金属离子的吸附动力学。研究结果表明:不同放电电压和放电时间对纤维素基水凝胶吸附重金属离子的吸质比有较大影响;纤维素基水凝胶对重金属离子的吸质比随着p H值的增加而增大,可在60 min时间内达到吸附平衡;吸附机制为离子交换吸附,吸附动力学可用准2级动力学模型和Langmuir等温方程描述;水凝胶经过吸附-脱附8次循环后,仍有较高的吸附效率。最终得出的结论为:在放电电压为620 V、放电时间为90 s的条件下,制得的纤维素基水凝胶对重金属离子Pd2+、Cd2+和Zn2+的最大吸质比分别可达0.597、0.425和0.168。该研究结论可以为进一步拓展液相放电技术的应用领域,处理重金属离子污染的废水提供理论依据。
In order to study the effects of glow discharge electrolysis plasma (GDEP) parameters on adsorption properties of cellulose-based hydrogel,a series of cellulose-based hydrogels were synthesized using various discharge voltage and discharge time. The adsorption capacity of hydrogels was tested through soak, oscillation, and standard EDTA titration experiments. The adsorption kinetics of hydrogels was investigated by accurate secondary dynamics model and the Langmuir isotherm equation. The results show that the discharge voltage and discharge time on hydrogel have great influences on the adsorption mass ratio. The adsorption mass ratio increases with the increasing ofpH value. The adsorption eqtfilibrium time is approximately 60 min. The adsorption process is an ion-exchange mechanism, which suggests that the adsorption kinetics fits the pseudo-second-order model and the adsorption follows the Langmuir model. Furthermore, cellulose-based hydrogel also exhibits highly adsorption efficiency of metal ions after 8 repeated adsorption/desorption cycles. Conclusions can be drawn that the maximum adsorption mass ratios of Pd2+, Cd2+, and Zn2+ are 0.597, 0.425 and 0.168, respectively, under 620 V and 90 s. The research conclusion can further expand the application field of the dis- charge technology and provide theory basis for the pollution of heavy metal ions wastewater treatment.