Degradation of 2, 4, 6-trinitotoluene in aqueous solution by ozonation and multi-stage ozonation biological treatment

ABSTRACT

The objective of this study was to explore the extent of 2, 4, 6-trinitrotoluene synthetic solution and red water mineralization by comparing conventional direct ozonation and multi-stage ozonation-biological treatment process. The alkaline hydrolysis was used for remediation 2, 4, 6-trinitrotoluene and red water at pH = 10.9. Nevertheless, the hydroxyl radicals would be generated by ozone decomposition with ozone dose of 0.177 g/L. The samples were subjected to chemical oxygen demand and total organic carbon analysis to monitor pollutants removal. The rate of 2, 4, 6-trinitrotoluene and red water pollutants degradation were quantified using high performance liquid chromatography. 2, 4, 6-trinitrotoluene synthetic solution resulted 55.5% chemical oxygen demand removal by 3 h direct ozonation. Following direct ozonation the biological treatment twenty four hours chemical oxygen demand reached 98.9% and 98.7% removal using humic acid and river water 1% [v/v] inoculation singly and respectively. Conventional direct ozonation showed non significant change in total organic carbon degradation. While on using multi-stage ozone-biological treatment process where humic acid and/or river water were used as inoculums singly and respectively, total organic carbon fulfilled 73% and 98.3% removal. The process was one hour direct ozonation and followed by three days multistage ozone-biological treatment. In multi-stage ozone-biological treatment process, ozonation was effective to decompose total organic carbon and to produce biodegradable dissolved organic carbon easily removed by ozone oxidation up to 98.3% in 2, 4, 6-trinitrotoluene synthetic solution. Pollutants removal achieved 99% in authentic red water effluent using river inoculation 1% [v/v] in 5 days. Nuclear Magnetic Resonance and Fourier Transformation Infra Red methods were performed to confirm types of pollutants content in red water