Preparation and nitrogen removal performance of magnetic amine-crosslinked biopolymer based reed straw

Abstract

In view of the waste of reed resources in Xiong’an New Area and the difficulty in separating the adsorbent in the process of removing nitrate nitrogen from water by adsorption，the magnetic amine-crosslinked biopolymer based reed straw was prepared from waste reed straw. The preparation method of the adsorbent was optimized by comprehensively considering the effects of reagent type，reagent dosage，reaction time，reaction temperature and other conditions during the preparation process. The adsorption performance of the adsorbent on simulated wastewater was investigated and characterized by SEM，VSM，FT-IR and XPS. The results showed that the removal rate of nitrate nitrogen in simulated sewage reached 93.2% by the adsorbent prepared by adding 5 mL of epichlorohydrin，20 mL of N，N-dimethylformamide and 5 mL of trimethylamine into 2 g of reed straw powder and reacting at 80 ℃ for 30 min. The static adsorption of nitrate nitrogen conformed to the Freundlich isotherm adsorption model and the quasi-second order adsorption kinetic model. In the dynamic adsorption experiment，the maximum adsorption capacity of the adsorbent for nitrate nitrogen was 12.74 mg/g. After six cycles of regeneration，the adsorption performance of the adsorbent had not significantly decreased. The characterization results showed that magnetic groups and quaternary amine groups were successfully loaded on the surface of the material，and the adsorption mechanism of nitrate nitrogen was mainly ion exchange. In conclusion，the prepared magnetic amine-crosslinked biopolymer based reed straw had good adsorption performance for nitrate nitrogen in water，and was expected to realize the high value utilization of reed resources.

Keywords

• adsorbents
• reed straw
• nitrate nitrogen