小麦淀粉生物基水凝胶合成及其辅助NO_(2)^(-)-N的去除

Synthesis of wheat starch bio-based hydrogel and its assisted removal for NO_(2)^(-)-N

针对小麦淀粉(CS)凝胶力学性能较差的缺陷,利用小麦淀粉与聚乙烯醇(PVA)、硼砂(B)、海藻酸钠(SA)等天然/无机材料通过物理/化学交联合成了PVA/B/CS和SA/B/CS 2种生物基水凝胶,考察其力学性能和溶胀性能;并制备生物基水凝胶包埋反硝化菌剂,考察其对水体中亚硝酸盐氮(NO_(2)^(-)-N)的去除性能。结果表明:合成的2种生物基水凝胶均具有良好的力学性能,PVA/B/CS水凝胶的拉伸断裂伸长率最高可达1088%,SA/B/CS水凝胶的拉伸断裂伸长率最高可达562%;PVA/B/CS2.7水凝胶包埋反硝化菌剂(D-PVA/B/CS2.7)去除水中NO_(2)^(-)-N 30 h后,去除效率为94.81%;SA/B/CS2.7水凝胶包埋反硝化菌剂(D-SA/B/CS2.7)去除水中NO_(2)^(-)-N 40 h后,去除效率为94.99%,说明所合成的生物基水凝胶具有辅助去除水体中氨氮的效果。

Aiming at the defect of poor mechanical properties of wheat starch(CS)gel,PVA/B/CS and SA/B/CS bio-based hydrogels were synthesized by physical/chemical crosslinking of wheat starch with natural/inorganic materials such as polyvinyl alcohol(PVA),borax(B)and sodium alginate(SA).The mechanical properties and swelling properties of two composite bio-based hydrogels were studied.Bio-based hydrogel entrapped denitrifying bacteria was prepared,and its removal performance of nitrite nitrogen(NO_(2)^(-)-N)in water was investigated.The results showed that the two bio-based hydrogels had good mechanical properties,the tensile elongation at break of PVA/B/CS hydrogels was up to 1088%,and the tensile elongation at break of SA/B/CS hydrogels was up to 562%.The removal efficiency of PVA/B/CS2.7 hydrogel-embedded denitrifying bacteria(D-PVA/B/CS2.7)for NO_(2)^(-)-N in water was 94.81%after 30 h.The removal efficiency of SA/B/CS2.7 hydrogel-embedded denitrifying bacteria(D-SA/B/CS2.7)for NO_(2)^(-)-N in water was 94.99%after 40 h.It indicates that the synthesized bio-based hydrogel has an auxiliary effect on the removal of ammonia nitrogen in water.