超声处理增强生物吸附剂去除废水中铅的研究

Research on Pb(II) Removal in Wastewater by Ultrasonic Enhanced Biosorbent

利用海藻酸钠包埋碳化核桃壳粉作为生物吸附剂,经超声处理,增强废水中铅离子去除。通过静态吸附实验方法对p H、吸附剂量、反应时间、温度和初始浓度进行优化研究,以获得最优参数。结果表明,最优吸附条件是:p H为6,吸附剂量0.1 g,25℃和铅离子质量浓度100 mg/L。超声处理120 min即可达到吸附平衡;同等条件下,铅离子吸附容量也提高约30%。准二级动力学模型和Langmuir吸附等温模型可以很好地拟合吸附实验,其中R2分别达到0.999 2和0.982 6。扫描电子显微镜和傅里叶变换红外光谱仪对生物吸附剂进行表征后,观察到吸附后的含铅结晶和测得羟基、氨基、酰胺基和羧基是起吸附作用的官能团。实际废水处理结果表明了该种方法对于处理低浓度的工业废水具有潜在的应用前景。

The alginate-coated carbonized walnut shell powder was used as biosorbent, and was prepared to enhance the lead removal from wastewater by ultrasonic treatment. The optimizations of pH, adsorbent dosage, reaction time, temperature and initial concentration were investigated to get the best parameters by static adsorption method.The results showed that the optimal parameters of pH, adsorbent dose, contact time, temperature and initial lead ions concentration were 6, 0.1 g, 25 ℃and 100 mg/L, respectively. The adsorption reached equilibrium within 120 min by ultrasonic treatment. Under the same conditions, the adsorption capacity increased nearly by 30% compared with the control. Pseudo-second-order kinetic model and Langmuir adsorption isotherm fitted well to the adsorption data and R2 was 0.999 2 and 0.982 6 respectively. Biosorbent was characterized by scanning electron microscope（SEM） and fourier transform infrared spectra（FTIR）. It was found that Pb（Ⅱ）-containing crystals, and hydroxyl, amino, amido and carboxyl groups were the functional groups for adsorption effect. Results of industrial effluents treatment suggested that this work has potential application prospects to deal with low concentration of industrial wastewater.