超支化聚合物改性胶原纤维(CF-HBPN)作为吸附剂处理含Cr(VI)模拟废水, 研究了CF-HBPN吸附Cr(VI)时溶液pH、吸附剂用量和Cr(VI)初始浓度等对去除效率的影响; 采用XPS, SEM-EDS等分析检测方法对CF-HBPN表面组成和结构进行表征, 探索吸附机理. 结果显示: CF-HBPN对Cr(VI)的去除率随溶液pH降低而升高, 在pH为3.0时达到最大, 随吸附剂用量增大而增大, 随Cr(VI)初始浓度增加而减小. CF-HBPN对Cr(VI)的吸附容量随吸附剂用量增加而减小, 随Cr(VI)初始浓度增加而增加, 最后趋于稳定. 30 ℃时, 4.0 g·L^-1的CF-HBPN对50 mg·L^-1 Cr(VI)溶液的去除率可达99.57%, 最大吸附容量为38.94 mg·g^-1. 0.18 mol·L^-1的NaOH溶液对吸附Cr(VI)后的CF-HBPN解吸效果最好. SEM-EDS分析结果表明CF-HBPN表面较粗糙, 是一种具有空间网状结构的材料, 吸附过程存在离子交换. XPS分析结果表明Cr(VI)主要吸附在CF-HBPN表面, 铬酸根阴离子与质子化氨基的静电吸附作用为主要吸附作用.

Hyperbranched polymer modified collagen fiber was used as a novel absorbent to remove hexavalent chromium from simulated chrome solution. Various factors influencing the uptake of Cr(VI), namely, quantity of absorbent, pH, the concentration of the simulated chrome solution and the duration of treatment had been studied. The experimental result indicated that the modified collagen fiber was very effective for removing Cr(VI) from simulated chrome solution. The removal of Cr(VI) increased with the decrease of solution pH values. The maximum rate of removal was attained at pH 3.0. The increase of absorbent dosage would raise the removal efficiency, but it would simultaneously reduce the adsorption capacity. Moreover, the removal rate of Cr(VI) was found to decrease with the increasing of initial concentration of Cr(VI). At pH 3.0, the temperature of 30 ℃, 4.0 g·L^-1 modified collagen fiber, the rate of removal could reach 99.57%. Whereas, the Cr(VI) uptake capacity increased with the increase of Cr(VI) initial concentration until reaching saturation, which was found to be 38.94 mg·g^-1 at pH 3.0, 30 ℃ and the initial concentration of 400 mg·L^-1. Several desorption solutions were used to analyze the desorption process while the 0.18 mol·L^-1 NaOH solution was the best. Furthermore, X-ray photoelectron spectroscopy (XPS) as well as scanning electron microscope and energy dispersive spectrometer (SEM-EDS) analysis were employed to characterize hyperbranched polyamide amino modified collagen fiber (CF-HBPN), and further to elucidate the adsorption mechanism involved in the process. XPS analysis revealed that the Cr(VI) combined on the surface of modified collagen fiber and the protonation amino groups were the functional groups in the adsorption process because of the electrostatic power. SEM analysis revealed that the surface of modified collagen fiber was rough and it had three-dimensional network structures. EDS analysis indicated that the adsorption process included ion exchange.