Guangxi Key Laboratory of Processing for Non-ferrous Metals and Featured Materials, School of Resources, Environment and Materials, Guangxi University, Nanning 530004, China; Nuclear Materials Authority, POB 530, El-Maadi, Cairo, Egypt.
Guangxi Key Laboratory of Processing for Non-ferrous Metals and Featured Materials, School of Resources, Environment and Materials, Guangxi University, Nanning 530004, China.
Sci Total Environ. 2020 Jun 1;719:137396. doi: 10.1016/j.scitotenv.2020.137396. Epub 2020 Feb 20.
Composite beads (APEI*), obtained by the controlled interaction of algal biomass with PEI, followed by ionotropic gelation and crosslinking processes using CaCl/glutaraldehyde solution, constitute efficient supports for metal binding. The quaternization of algal/PEI beads (Q-APEI*) significantly increases the sorption properties of the composite beads (APEI*) for As(V). The materials are characterized by SEM/EDX, TGA, BET, elemental analysis, FTIR, XPS, and titration. The sorption of As(V) is studied in function of pH while sorption mechanism is discussed in function of metal speciation and surface characteristics of the sorbent. Optimum sorption occurs at pH close to 7. Fast uptake kinetics, correlated to textural properties are successfully fitted by pseudo-first order rate equation and the Crank equation (for resistance to intraparticle diffusion); equilibrium is reached with 45-60 min. The Langmuir equation finely fits sorption isotherms; maximum sorption capacity reaches 1.34 mmol As g. Arsenic can be completely eluted using 0.5 M CaCl/0.5 M HCl solutions; the sorbent maintains high sorption and desorption efficiencies for a minimum of 5 cycles. The sorbent is tested for the removal of As(V) from mining effluents containing high concentration of iron and traces of zinc. At pH 3, the sorbent shows remarkable selectivity for As(V) over Fe. After controlling the initial pH to 5, a sorbent dosage of 2 g L is sufficient for achieving the complete recovery of As(V) from mining effluent (corresponding to initial concentration of 1.295 mmol As L).
复合珠粒（APEI*）是通过藻生物质与 PEI 的受控相互作用获得的，随后使用 CaCl/戊二醛溶液进行离子凝胶化和交联过程，构成了有效结合金属的载体。藻/PEI 珠粒（Q-APEI*）的季铵化显著提高了复合珠粒（APEI*）对 As(V)的吸附性能。材料通过 SEM/EDX、TGA、BET、元素分析、FTIR、XPS 和滴定进行表征。研究了 As(V)的吸附与 pH 的关系，同时根据金属形态和吸附剂表面特性讨论了吸附机理。最佳吸附发生在接近 pH7 的条件下。快速的吸收动力学与结构特性有关，成功地通过拟一级速率方程和 Crank 方程（用于抵抗颗粒内扩散）进行拟合；45-60min 内达到平衡。Langmuir 方程很好地拟合了吸附等温线；最大吸附容量达到 1.34mmol As g。使用 0.5M CaCl/0.5M HCl 溶液可以完全洗脱砷；吸附剂在至少 5 个循环中保持高的吸附和解吸效率。该吸附剂用于从含有高浓度铁和痕量锌的采矿废水中去除 As(V)。在 pH3 时，该吸附剂对 As(V)表现出对 Fe 的显著选择性。控制初始 pH 值为 5 后，2g L 的吸附剂用量足以从采矿废水中完全回收 As(V)（对应于初始浓度为 1.295mmol As L）。
