Abstract:
Natural astaxanthin has been widely used in the food, cosmetic, and medicine industries due to its exceptional biological activity. Shrimp shell is one of the primary natural biological sources of astaxanthin. However, after astaxanthin recovery, there is still a lot of chitin contained in the residues. In this study, the residue from shrimp (Penaeus vannamei) shells after astaxanthin extraction using ionic liquid (IL) 1-ethyl-3-methyl-imidazolium acetate ([Emim]Ac) was used as a bioadsorbent to remove fluoride from the aqueous solution. The results show the IL extraction conditions, including the solid/liquid ratio, temperature, time, and particle size, all played important roles in the removal of fluoride by the shrimp shell residue. The shrimp shells treated using [Emim]Ac at 100 °C for 2 h exhibited an obvious porous structure, and the porosity showed a positive linear correlation with defluorination (DF, %). Moreover, the adsorption process of fluoride was nonspontaneous and endothermic, which fits well with both the pseudo-second-order and Langmuir models. The maximum adsorption capacity calculated according to the Langmuir model is 3.29 mg/g, which is better than most bioadsorbents. This study provides a low-cost and efficient method for the preparation of adsorbents from shrimp processing waste to remove fluoride from wastewater.
摘要:
天然虾青素已广泛应用于食品中,化妆品,和医药工业由于其特殊的生物活性。虾壳是虾青素的主要天然生物来源之一。然而,虾青素恢复后,残留中仍含有大量的甲壳素。在这项研究中,使用离子液体(IL)1-乙基-3-甲基咪唑鎓乙酸盐([Emim]Ac)提取虾青素后的虾(南美白对虾)壳中的残留物用作生物吸附剂以从水溶液中去除氟化物。结果表明,IL的提取条件,包括固体/液体比,温度,时间,和颗粒大小,所有这些都在虾壳残留物去除氟化物中起着重要作用。用[Emim]Ac在100°C下处理2h的虾壳表现出明显的多孔结构,孔隙率与脱氟呈正线性相关(DF,%).此外,氟的吸附过程为非自发吸热,这与伪二阶和朗缪尔模型都很好地吻合。根据Langmuir模型计算的最大吸附容量为3.29mg/g,比大多数生物吸附剂更好。本研究为从虾加工废弃物中制备吸附剂去除废水中的氟提供了一种低成本、高效的方法。