在可见光照射下(λ〉450 nm),以负载Fe2+的NaY分子筛制备得到Fe2+-NaY催化剂(简称FeY),研究了FeY/H2O2降解微囊藻毒素-LR(MC-LR)的机理,发现在宽pH范围内,Vis/FeY/H2O2体系对MC-LR降解率大于90%。采用LC-MS跟踪分析降解中间产物,推测了可能的降解路径和3个易被氧化的位点:N-甲基脱氢丙氨酸(Mdha链)上的不饱和双键,3-氨基-9-甲氧基-2,6,8-三甲基-10-苯基-4(E),6(E)-二烯酸(Adda链)上的共轭二烯双键与甲氧基。FeY催化剂稳定性良好,循环使用5次仍保持高活性,此催化体系对藻毒素废水的处理具有潜在的应用价值。
Under the condition of visible light irradiation(λ450 nm),the degradation mechanism of microcystin-LR was studied using H2O2 and FeY catalyst,which is prepared by means of loading Fe2+ to the molecular sieve NaY.The results indicate that the degradation rate of microcystin-LR is up to 90% in the wide pH range using Vis/FeY/H2O2 system.Based on the intermediates detected by LC-MS analysis,the possible pathways and three vulnerable oxidation sites are put forward:(1) the conjugated double bonds of the Adda chain,(2) the methoxy group of the Adda chain,(3) unsaturated double bond of the Mdha chain.FeY catalyst is of good stability,having catalytic activity after 5 times repetition,which indicates its potential application to the control of the alga wastewater.