Kondaveeti Stalin, Petri Denise F S, Jeong Hoon Eui
Instituto de Química, Universidade de São Paulo, Av. Prof. Lineu Prestes 748, 05508-000 São Paulo, Brazil; Department of Mechanical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Republic of Korea.
Instituto de Química, Universidade de São Paulo, Av. Prof. Lineu Prestes 748, 05508-000 São Paulo, Brazil.
Int J Biol Macromol. 2022 Apr 15;204:345-355. doi: 10.1016/j.ijbiomac.2022.02.011. Epub 2022 Feb 9.
Alginate (Alg) beads are low-cost adsorbents used for wastewater remediation. In this work, alginate (Alg) and alginate/xanthan (Alg/XG) blend beads were synthesized by gelation method into calcium chloride and freeze-dried to improve the porosity. Their adsorption efficiency was tested for methylene blue (MB) dye in batch, recirculating and column adsorption systems. The blend beads were characterized using by SEM, FTIR-ATR and X-ray microcomputer tomography (Micro-CT) analyzes. Freeze-dried Alg and Alg/XG beads presented porosity of 46 ± 5% and 77 ± 3%, respectively. Adsorption isotherms of MB on freeze-dried Alg/XG beads indicated better adsorption capacity in comparison to the air-dried ones. Adsorption kinetics and breakthrough curves based on recirculating and vertical column adsorption processes of MB on freeze dried Alg/XG and air-dried Alg/XG beads indicated higher efficiency for the vertical column system packed with freeze dried Alg/XG beads. The removal efficiency of 91% MB by the freeze-dried Alg/XG beads in vertical column remained even after four consecutive adsorption-desorption cycles, disclosing these beads as potential systems for the wastewater treatment.
海藻酸钠（Alg）珠粒是用于废水修复的低成本吸附剂。在本研究中，通过凝胶法将海藻酸钠（Alg）和海藻酸钠/黄原胶（Alg/XG）共混珠粒在氯化钙中合成并冻干以提高孔隙率。在间歇、循环和柱吸附系统中测试了它们对亚甲基蓝（MB）染料的吸附效率。通过扫描电子显微镜（SEM）、傅里叶变换红外衰减全反射光谱（FTIR-ATR）和X射线微型计算机断层扫描（Micro-CT）分析对共混珠粒进行了表征。冻干的Alg和Alg/XG珠粒的孔隙率分别为46±5%和77±3%。MB在冻干的Alg/XG珠粒上的吸附等温线表明，与风干珠粒相比，其吸附容量更高。基于MB在冻干的Alg/XG和风干的Alg/XG珠粒上的循环和垂直柱吸附过程的吸附动力学和穿透曲线表明，填充冻干的Alg/XG珠粒的垂直柱系统效率更高。即使在连续四个吸附-解吸循环后，冻干的Alg/XG珠粒在垂直柱中对MB的去除效率仍保持在91%，表明这些珠粒是潜在的废水处理系统。
