Jakóbik-Kolon Agata, Mitko Krzysztof, Bok-Badura Joanna
Faculty of Chemistry, Silesian University of Technology, Krzywoustego 6, Gliwice 44-100, Poland.
Materials (Basel). 2017 Jul 22;10(7):844. doi: 10.3390/ma10070844.
The previously-obtained and characterized hybrid pectin-based beads containing agar-agar and guar gum, as well as sole pectin beads (P, for comparison) were examined for zinc ions sorption and desorption properties. The sorption kinetics and equilibrium in the studied system was described by two kinetic models (pseudo-first- and pseudo-second-order) and two isotherms (Langmuir and Freundlich), respectively. The desorption kinetics and equilibrium was also investigated by applying various inorganic acids (nitric, hydrochloric, and sulfuric acid) of various concentrations. In the case of guar gum additive, no significant change in sorption capacity compared to sole pectin beads was observed (q: 37.0 ± 2.6 and 34.7 ± 2.0 mg/g, respectively). Addition of agar-agar significantly decreased the sorption capacity to 22.3 ± 1.0 mg/g, but stripping of zinc(II) ions from this biosorbent was complete even with very diluted acids (0.01 M). Total desorption of zinc from sole pectin and pectin-guar gum beads required acid solution of higher concentration (0.1 M). Sorption rates for all biosorbents are roughly the same and maximum sorption is achieved after 4-5 h. Obtained results and the advantage of our sorbent's shape formation ability, make the pectin-based biosorbents interesting alternative for zinc(II) ions removal.
研究了先前制备并表征的含有琼脂和瓜尔胶的混合果胶基珠粒以及单一果胶珠粒（P，用于比较）对锌离子的吸附和解吸性能。分别用两种动力学模型（伪一级和伪二级）和两种等温线（朗缪尔和弗伦德里希）描述了所研究体系中的吸附动力学和平衡。还通过应用不同浓度的各种无机酸（硝酸、盐酸和硫酸）研究了解吸动力学和平衡。在添加瓜尔胶的情况下，与单一果胶珠粒相比，未观察到吸附容量有显著变化（q分别为37.0±2.6和34.7±2.0 mg/g）。添加琼脂显著降低了吸附容量至22.3±1.0 mg/g，但即使使用非常稀的酸（0.01 M），这种生物吸附剂上的锌（II）离子也能完全解吸。从单一果胶和果胶-瓜尔胶珠粒中完全解吸锌需要更高浓度（0.1 M） 的酸溶液。所有生物吸附剂的吸附速率大致相同，4-5小时后达到最大吸附量。所获得的结果以及我们的吸附剂形成形状的能力优势，使得基于果胶的生物吸附剂成为去除锌（II）离子的有趣替代物。
