Intensified peroxydisulfate/microparticles-zero valent iron process through aeration for degradation of organic pollutants: Kinetic studies, mechanism and effect of anions
Intensified peroxydisulfate/microparticles-zero valent iron process through aeration for degradation of organic pollutants: Kinetic studies, mechanism and effect of anions
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DOI：
10.1016/j.jwpe.2020.101321
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发表时间：
2020-08-01
影响因子：
7
通讯作者：
Lin, Kun-Yi Andrew
中科院分区：
文献类型：
--
作者：
Ghanbari, Farshid;Riahi, Mahtab;Lin, Kun-Yi Andrew
有机染料对水体的污染已引起给水和废水处理工程师的重视。文献中已经提出了几种方法，特别是高级氧化工艺。基于过二硫酸盐(PDS)的工艺是降解有机污染物的一种强有力的技术。微量零价铁(MZVI)/曝气也是产生Fenton试剂的一种简单方法。本研究首次采用PDS/mZVI/曝气工艺降解酸性蓝9(AB9)。对操作参数、各种阴离子、铁的释放和反应动力学进行了综合考察。在pDS=1.5 mM、mZVI=0.5g/L的条件下，AB9在10min内迅速降解，降解符合准一级动力学模型，反应速率常数为0.2039 m in−1。与mZVI相比，零价铝对pDS的活化作用不明显。清除实验表明，硫酸根(SO4自由基点-)对AB9的降解起主导作用。碳酸盐和亚硝酸盐阴离子几乎完全抑制AB9的降解。阴离子对反应过程的负效应顺序为：CO32−>；NO2−>；I−>；H2PO4−>；bR−>；Cl−>；NO3−≥SO42−。监测了AB9降解产生的羧酸。结果表明，进一步的氧化导致了小分子羧酸的生成。在120min的反应过程中，AB9约有60%的有机碳被矿化。MZVI在溶液中的释放率为7.0%。FESEM、EDS和X射线衍射仪分析表明，mZVI被氧化为Fe2O3。结果表明，PDS/mZVI/曝气是一种简单有效的有机染料降解工艺。
Water pollution by organic dyes has been considered by water and wastewater engineers. Several methods have been suggested in literature especially advanced oxidation processes. Peroxydisulfate (PDS)-based processes are a powerful technique for the degradation of organic pollutants. Micro-zero valent iron (mZVI)/aeration is also a simple method for the generation of Fenton reagent. In this study, PDS/mZVI/aeration was used for the first time to degrade Acid Blue 9 (AB9). Operating parameters, various anions, iron release and reaction kinetic were comprehensively investigated. A rapid degradation of AB9 was observed after only 10 min under conditions of PDS = 1.5 mM and mZVI = 0.5 g/L. Pseudo-first order kinetic model was fitted for AB9 degradation with the rate constant of 0.2039 min−1. In contrast with mZVI, zero valent aluminum was ineffective to activate PDS. Scavenging tests demonstrated that sulfate radical (SO4radical dot-) was dominated for the degradation of AB9. Carbonate and nitrite anions almost completely suppressed AB9 degradation. The negative effect of anions on the process was based on this order CO32−> NO2−> I−> H2PO4−> Br−> Cl−> NO3−≥ SO42−. Carboxylic acids generated arise from AB9 degradation were monitored. The results showed that further oxidation led to the generation of the small molecules of carboxylic acids. Around 60% of organic carbon of AB9 was mineralized during 120 min reaction. 7.0% of mZVI was released in the solution. FESEM, EDS, and XRD analyses showed that mZVI was oxidized to Fe2O3. Finally, PDS/mZVI/aeration showed a simple and efficient process for degradation of organic dye.