State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan University, Changsha 410082, PR China; College of Life Science and Chemistry, Hunan University of Technology, Hunan 412007, PR China.
Brook Byers Institute for Sustainable Systems and School of Civil and Environmental Engineering, Georgia Institute of Technology, 828 West Peachtree Street, Atlanta, GA 30332, United States.
Water Res. 2018 Mar 15;131:246-254. doi: 10.1016/j.watres.2017.12.067. Epub 2017 Dec 27.
High adsorption capacity, fast adsorption kinetics, good reusability and low cost are highly demanded for adsorbents used in practical adsorption process. In this study, a porous double network Jute/Polyacrylic acid (Jute/PAA) gel was prepared using simple free-radical polymerization of acrylic acid in Jute aqueous solution. The high permeability of Jute/PAA hydrogel with about 80 wt% water made internal adsorption sites fully expose to metal ions. The Jute/PAA gel adsorbent could efficiently adsorb heavy metals in melting wastewater, especially Cd and Pb. The adsorbent showed very high adsorption capacities of 401.7 mg/g for Cd and 542.9 mg/g for Pb. Moreover, the adsorption equilibrium reached within only 10 min for 40 mg/L of Cd and Pb using 1 g/L adsorbent. Meanwhile, the removal efficiencies reached 81.0% for Pb (C = 3.825 mg/L), 79.3% for Cd (C = 6.075 mg/L), 83.4% for Cu (C = 9.325 mg/L), 29.8% for Zn (C = 188.6 mg/L), 22.3% for Mn (C = 17.05 mg/L), 96.2% for Cr (C = 0.25 mg/L) and 99.8% for Fe (C = 9.75 mg/L) in melting wastewater using 1 g/L adsorbent in 2 h. In particular, the concentrations of Pb, Cd and Cr decreased below 0.001 mg/L using 4 g/L adsorbent. In the fixed-bed column experiments, the treatment volume of melting wastewater reached 2900 BV (32.8 L) only producing 50 BV (565 mL) eluent. This work develops a highly practical adsorption process based on hydrogel adsorbents for the removal of heavy metals in actual wastewater.
高吸附容量、快速吸附动力学、良好的可重复使用性和低成本是实际吸附过程中对吸附剂的高度要求。在这项研究中，通过在黄麻水溶液中简单的自由基聚合制备了多孔双网络黄麻/聚丙烯酸（Jute/PAA）凝胶。Jute/PAA 水凝胶的高渗透性能（约 80wt%的水）使内部吸附位充分暴露于金属离子。Jute/PAA 凝胶吸附剂可以有效地吸附废水中的重金属，尤其是 Cd 和 Pb。该吸附剂对 Cd 和 Pb 的吸附容量分别高达 401.7mg/g 和 542.9mg/g。此外，对于 40mg/L 的 Cd 和 Pb，仅需 1g/L 的吸附剂在 10min 内即可达到吸附平衡。同时，在 2h 内使用 1g/L 的吸附剂，Pb（C=3.825mg/L）的去除率达到 81.0%，Cd（C=6.075mg/L）的去除率达到 79.3%，Cu（C=9.325mg/L）的去除率达到 83.4%，Zn（C=188.6mg/L）的去除率达到 29.8%，Mn（C=17.05mg/L）的去除率达到 22.3%，Cr（C=0.25mg/L）的去除率达到 96.2%，Fe（C=9.75mg/L）的去除率达到 99.8%。特别是，当使用 4g/L 的吸附剂时，Pb、Cd 和 Cr 的浓度降低至 0.001mg/L 以下。在固定床柱实验中，处理的熔融废水体积达到 2900BV（32.8L），仅产生 50BV（565mL）洗脱液。这项工作基于水凝胶吸附剂开发了一种高度实用的吸附工艺，用于去除实际废水中的重金属。
