黄原酸化废弃污泥吸附Cu2+研究

Adsorption of Cu^(2+) by Xanthate-Functionalized Waste Sludge

将污水处理厂废弃污泥在碱性环境中用CS2处理,制备黄原酸酯类重金属吸附剂,探究一种有效的废弃污泥资源化途径.用傅里叶转换红外光谱(fourier transform infrared spectroscopy,FTIR)对污泥进行了表征,并通过批量实验研究了污泥对Cu2+的吸附性能以及pH和初始Cu2+浓度的影响.结果表明,黄原酸化成功引入了含硫基团,使黄原酸化污泥的吸附量相对于原始废弃污泥提高了20.6%~46.9%.当Cu2+初始浓度为25 mg·L-1时,黄原酸化污泥对Cu2+的去除率可达96.7%.吸附动力学遵循准二级动力学模型(Pseudo-second-order equation),平衡时间为3 h,吸附速率同时受膜扩散和颗粒内扩散两过程控制;吸附过程符合Langmuir等温模型和Freundlich等温模型,25℃下,由Langmuir模型得到的最大吸附量达142.92 mg·g-1(pH=5),且吸附容量随pH(1~5)及初始Cu2+浓度升高而升高.黄原酸化废弃污泥可作为高效重金属离子吸附剂,实现废弃资源的回收利用.

Waste sludge from waste water treatment plants was treated with the carbon disulfide in alkaline medium to prepare xanthate, aiming to explore an efficient way to recycle waste sludge. Fourier transform infrared spectroscopy( FTIR) was applied to characterize the sludge. Batch experiments were conducted to investigate the adsorption property of Cu2 +as well as effecting factors including pH and initial concentration of Cu2 +. Results show that the chemical modification introduces sulfur groups successfully and the adsorption capacity of xanthate-functionalized sludge increases by 20. 6%-46. 9% comparing to the pristine waste sludge. The Cu2 +removal efficiency of xanthate-functionalized sludge reaches 96. 7% when the initial concentration of Cu2 +is 25 mg·L- 1. The adsorption process can attain equilibrium within 3 hours and kinetics is found to be best-fit the Pseudo-second-order equation. The process is jointly controlled by film diffusion and intraparticle diffusion. Both Langmuir model and Freundlich model can describe the adsorption process well. The maximum adsorption capacity given by the Langmuir model is 142. 92 mg·g- 1at 25℃( pH = 5). Adsorption capacity increases with pH value( 1-5) and initial Cu2 +concentration. The xanthate-functionalized sludge can be used as highperformance adsorbents to recycle waste resources.