Potassium Ferrate (VI) as the Multifunctional Agent in the Treatment of Landfill Leachate

Maciej Thomas; Violetta Kozik; Krzysztof Barbusiński; Aleksander Sochanik; Josef Jampilek; Andrzej Bąk

doi:10.3390/ma13215017

Potassium Ferrate (VI) as the Multifunctional Agent in the Treatment of Landfill Leachate

Materials (Basel). 2020 Nov 6;13(21):5017. doi: 10.3390/ma13215017.

Authors

Maciej Thomas¹, Violetta Kozik², Krzysztof Barbusiński³, Aleksander Sochanik⁴, Josef Jampilek⁵, Andrzej Bąk²

Affiliations

¹ Chemiqua Water&Wastewater Company, Skawińska 25/1, 31-066 Kraków, Poland.
² Institute of Chemistry, University of Silesia, Szkolna 9, 40-007 Katowice, Poland.
³ Department of Water and Wastewater Engineering, Silesian University of Technology, Konarskiego 18, 44-100 Gliwice, Poland.
⁴ Center for Translational Research and Molecular Biology of Cancer, Maria Skłodowska-Curie Memorial Cancer Center and Institute of Oncology, Wybrzeże AK 15, 44-101 Gliwice, Poland.
⁵ Department of Analytical Chemistry, Faculty of Natural Sciences, Comenius University, Ilkovicova 6, 84215 Bratislava, Slovakia.

Abstract

Possible use of potassium ferrate (VI) (K₂FeO₄) for the treatment of landfill leachate (pH = 8.9, Chemical Oxygen Demand (COD) 770 mg O₂/L, Total Organic Carbon (TOC) 230 mg/L, Total Nitrogen (Total N) 120 mg/L, Total Phosphorus (Total P) 12 mg/L, Total Coli Count (TCC) 6.8 log CFU/mL (Colony-Forming Unit/mL), Most Probable Number (MPN) of fecal enterococci 4.0 log/100 mL, Total Proteolytic Count (TPC) 4.4 log CFU/mL) to remove COD was investigated. Central Composite Design (CCD) and Response Surface Methodology (RSM) were applied for modelling and optimizing the purification process. Conformity of experimental and predicted data (R² = 0.8477, R_adj² = 0.7462) were verified using Analysis of Variance (ANOVA). Application of K₂FeO₄ using CCD/RSM allowed to decrease COD, TOC, Total N, Total P, TCC, MPN of fecal enterococci and TPC by 76.2%, 82.6%, 68.3%, 91.6%, 99.0%, 95.8% and 99.3%, respectively, by using K₂FeO₄ 0.390 g/L, at pH = 2.3 within 25 min. Application of equivalent amount of iron (as FeSO₄ × 7H₂O and FeCl₃ × 6H₂O) under the same conditions allowed to diminish COD, TOC, Total N, Total P, TCC, MPN of fecal enterococci and TPC only by 38.1%, 37.0%, 20.8%, 95.8%, 94.4%, 58.2%, 90.8% and 41.6%, 45.7%, 29.2%, 95.8%, 92.1%, 58.2%, 90.0%, respectively. Thus, K₂FeO₄ could be applied as an environmentally friendly reagent for landfill leachate treatment.

Keywords: central composite design; landfill leachate; potassium ferrate (VI); response surface methodology.