| Popis: |
Industrial wastewater has brought huge disasters to water bodies and soil, and seriously affected the growth of crops. In order to obtain clean water, a stable, effective and sustainable treatment agent must be prepared to control water pollution. The lignin-based hydrogel adsorbent was prepared on polyacrylic acid by free radical polymerization of sodium lignosulfonate and chitosan, which was applied to remove Pd2+ and Cd2+. The orthogonal method was used to optimize the content of sodium lignosulfonate, chitosan, cross-linking agent and initiator. Fourier infrared spectrometer, scanning electron micrograph, thermal analyzer and Zeta potentiometer were used to characterize the adsorbent. The effects of different conditions on the adsorption of Pb2+ and Cd2+ by lignin-based hydrogels were discussed, and the kinetics and isotherm models on the basis were established. The results show that when the adsorbent is 0.015 g, the concentration of heavy metal ions is 100 mg·L-1, and the pH value is 7, the adsorption capacity for Pd2+ is 367 mg·g-1 and the adsorption capacity for Cd2+ is 296 mg·g-1. Simultaneously, it is revealed that the adsorption process of lignin-based hydrogels is an adsorption mode in which electrostatic adsorption is supplemented by chemical adsorption. |
