Intensified peroxydisulfate/microparticles-zero valent iron process through aeration for degradation of organic pollutants: Kinetic studies, mechanism and effect of anions
| Autor: | Farshid Ghanbari, Xiaoting Hong, Babak Kakavandi, Mahtab Riahi, Kun-Yi Andrew Lin |
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| Rok vydání: | 2020 |
| Předmět: |
Pollutant
Zerovalent iron Process Chemistry and Technology Inorganic chemistry 02 engineering and technology 010501 environmental sciences 01 natural sciences chemistry.chemical_compound Reaction rate constant 020401 chemical engineering chemistry Wastewater Peroxydisulfate Degradation (geology) 0204 chemical engineering Nitrite Aeration Safety Risk Reliability and Quality Waste Management and Disposal 0105 earth and related environmental sciences Biotechnology |
| Zdroj: | Journal of Water Process Engineering. 36:101321 |
| ISSN: | 2214-7144 |
| Popis: | 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 (SO4 -) 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. |
| Databáze: | OpenAIRE |
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