镁改性生物炭/海藻酸钇杂化气凝胶对直接蓝86的超高效吸附

Super-Efficient Adsorption of Direct Blue 86 on Mg-Modified Biochar/Yttrium Alginate Hybrid Aerogel

摘要: 由农业秸秆生物炭(BC)为基质，并经MgCl₂改性为Mg-BC，再以海藻酸钠(SA)与Y(III)离子交联聚合形成的海藻酸盐凝胶球为骨架，制得了可持续、可分离、易回收利用的镁改性生物炭/海藻酸钇杂化气凝胶(Mg-BC/SA-Y)，对其进行SEM表征。以染料废水中的直接蓝86 (DB 86)作为吸附对象，探究了染料溶液初始pH值及吸附时间和温度对吸附性能的影响。研究结果显示，在pH 2.0和298 K条件下，Mg-BC/SA-Y气凝胶对DB 86的吸附去除率可达99.3%，且在pH 2.0~10.0范围内，去除率仍能保持在90%以上。Mg-BC/SA-Y气凝胶对DB 86的吸附过程遵循拟二级速率模型，等温吸附行为符合Langmuir模型，最大吸附容量可达1572 mg/g。Mg-BC/SA-Y气凝胶是一种在染料废水处理方面极具前景的吸附材料。

Abstract: The sustainable, separable and easily recyclable Mg-modified biochar/yttrium alginate hybrid aerogel (Mg-BC/SA-Y) was prepared from agricultural straw biochar (BC) as matrix and modified to Mg-BC by MgCl₂, and then crosslinked polymerization of sodium alginate (SA) with Y(III) ions to form alginate gel sphere as skeleton, and it was characterized by SEM. Direct Blue 86 (DB 86) from dye wastewater was used as the adsorption target, and the effects of the initial pH of the dye solution and the adsorption time and temperature on the adsorption performance were investigated. The results showed that the adsorption removal of DB 86 by Mg-BC/SA-Y aerogel could reach 99.3% at pH 2.0 and 298 K, and the removal rate could still be maintained above 90% in the pH 2.0-10.0 range. The adsorption process of DB 86 by Mg-BC/SA-Y aerogel followed the Pseudo-second-order rate model, and the isothermal adsorption behavior was consistent with the Langmuir model, and the maximum adsorption capacity up to 1572 mg/g. Mg-BC/SA-Y aerogel is a promising adsorbent material for dye wastewater treatment.