Kinetics and thermodynamics of photocatalytic degradation of acridine orange and optimization studies for the process using RSM

Abstract

Fluorescent dyes may be regarded as surrogates for pollutants. These cause contamination of springs, wells or any other water resources beyond permissible standards. This leads to the emergence of toxic, carcinogenic and mutagenic by-products following physical, chemical, or biological degradation and affects taste, odour and colour of the water. One such dye, Acridine Orange (AO) is a heterocyclic dye chemical with nitrogen atoms that is widely used in the dyeing, leather, printing ink, and lithography industries. Its mutagenic potential was recognised in toxicity studies. The release of this coloured water into the ecosystem is a significant cause of water pollution, eutrophication, and disruption of aquatic life. The current study focuses on the experiment results from batch experiments on the aqueous dye Acridine Orange (AO) degradation employing TiO2 NPs as a photocatalyst. The ideal values of various process parameters, including contact time (min), photocatalyst dose (g/L), pH, starting dye concentration (ppm), and temperature (K), were observed during investigation studies. Kinetic studies for finding the rate constant and thermodynamic studies for calculating different energies were evaluated. For the degrading process, response surface methodology investigations (central composite design) were also conducted.