Evaluation of the effectiveness of red mud-supported catalysts in combination with ozone and TiO2 in the treatment of solution containing benzene, toluene, and xylene

• Published in: Environmental monitoring and assessment Vol. 190; no. 9; pp. 1 - 12
• Main Authors: de Lima, Bernardo Alves, de Castro, Pedro Paulo Rocha, França, Alexandre Boscaro, Baston, Eduardo Prado, Lofrano, Renata Carolina Zanetti, Samanamud, Gisella Rossana Lamas, Loures, Carla Cristina Almeida, Naves, Luzia Lima Rezende, Naves, Fabiano Luiz
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01.09.2018; Springer Nature B.V
• Subjects: Aluminium; Aluminum; Atmospheric Protection/Air Quality Control/Air Pollution; Beads; Benzene; Biochemical oxygen demand; Biodegradability; Biodegradation; Catalysis; Catalysts; Chemical oxygen demand; Correlation analysis; Earth and Environmental Science; Ecology; Ecotoxicology; Environment; Environmental Management; Environmental monitoring; Environmental science; Evaluation; Hydrocarbons; Iron; Mathematical models; Monitoring/Environmental Analysis; Organic chemistry; Oxidation; Oxidation process; Oxygen; Ozone; Pretreatment; Red mud; Reduction; Response surface methodology; Slurries; Titanium dioxide; Toluene; Total oxygen demand; Variance analysis; Xylene; Ozonation; Fenton; Red mud; Catalyst; Optimization
• ISSN: 0167-6369; 1573-2959
• DOI: 10.1007/s10661-018-6924-8

Ozone and a Fe 2+ /TiO 2 -based catalyst were examined in the degradation of a synthetic solution of benzene toluene and xylene (BTX) in an advanced oxidation process (AOP). The catalyst beads were made from the slurry waste of aluminum production process, by inserting the TiO 2 content and subsequent calcination. The reduction of the BTX concentration load was monitored by the reduction of chemical oxygen demand (COD) and BTX concentration. Different levels were used on factors: pH, time of treatment, initial concentration of BTX, and percentage of TiO 2 . The process was conducted in a bubble column reactor with the insertion of catalyst beads. A response surface methodology technique (CCD) was used to build a model based on COD reduction results. The model was optimized using the normal-boundary intersection (NBI) algorithm to maximize COD reduction and minimize the variance attributed to the process. Optimization led to COD reductions of 80% in 2 h of experiment. Correlation analysis of coefficient models from experimental data R 2 adj was 0.9966, showing a good fit of model data. In the optimized conditions, the possible increase of the biodegradability ratio of the BTX solution, through the biochemical oxygen demand (BOD) and COD, was also analyzed. Under pre-treatment conditions, the BOD/COD ratio was 0.13. After the treatment, it increased to 0.56. Graphical abstract ᅟ