太阳光联合高碘酸盐降解水中新污染物卡马西平

Degradation of carbamazepine by periodate combined with solar light in water

以卡马西平(CMZ)为目标污染物,探索太阳光(SL)活化高碘酸盐(PI)降解CMZ的效能及机理.结果表明,在一定条件下([PI]=0.1 mmol·L^(-1),[CMZ]=5μmol·L^(-1)),SL/PI体系可在20 min内完全去除CMZ,且在酸性和中性条件下更有利于CMZ的降解.活性物种淬灭与电子顺磁共振分析显示,羟基自由基(·OH)、单线态氧(^(1)O_(2))、超氧自由基(O_(2)^(·-))和碘酸根自由基(·IO_(3)、·IO_(4))是SL/PI体系中去除CMZ的主要活性物种.水中Mn^(2+)、Fe^(3+)和NO_(3)^(-)对体系降解有轻微促进作用;低浓度的Cl^(-)对降解无明显影响,而高浓度的Cl^(-)有轻微促进作用;HCO_(3)^(-)和腐殖酸(HA)对降解有一定抑制作用;SO_(4)^(2-)则无明显影响.通过对不同反应时间的中间产物进行测定分析,共检测出5种中间产物,并提出了4种CMZ可能的降解途径.同时,通过评估其降解中间产物的毒性,发现SL/PI体系对CMZ的降解伴随着解毒作用.此外,SL/PI体系在实际水体及多种典型新污染物中均表现出较好的处理效能.

The elimination of carbamazepine (CMZ) by periodate (PI) combined with solar light (SL) was examined in detail.The results indicated that CMZ would be completely removed by the SL/PI system ([PI]=0.1 mmol·L^(-1),[CMZ]=5μmol·L^(-1)).Meanwhile,it was more conducive for CMZ removal under acidic and neutral conditions.Singlet oxygen (~1O_(2)),superoxide anion radical (O_(2)^(·-)),and iodate radicals(·IO_(3)、·IO_(4)) were proved to be the main reactive species in SL/PI system,based on electron paramagnetic resonance analysis and quenching tests.Mn^(2+)、Fe^(3+)and NO_(3)^(-)accelerated the CMZ removal.Particularly,the promotion of removal might be connected with metal ions’abilities to absorb light and react with PI.It was worth noting that a low concentration of Cl^(-) had an inconspicuous effect on CMZ removal,while a high concentration had a slight promotion effect.HCO_(3)^(-)and humic acid (HA) inhibited the removal and SO_(4)^(2-)had insignificant effect.Five intermediates were identified and four probable pathways were assumed.Moreover,it was determined that the removal of CMZ by the SL/PI system was accompanied by detoxification.In addition,the SL/PI system represented workable both in real waters and various emerging pollutants.