Process parameter optimization for the detoxification of emerging environmental pollutant, PPD

Paraphenylenediamine (PPD) is an aromatic compound widely used in hair dye, tattoos, plastic, and rubber industry. The effluent of these industries may express an adverse effect onhe entire ecosystem as PPD is reported as a toxic, and environmental hazard. Since the usage has increased, the removal of PPD from the environment is essential. The present study reports the detoxification of PPD using the bacterial strain in an eco-friendly manner at low cost, with an in-depth study of the mechanism of detoxification and optimization of process parameters which will be helpful for designing a bioreactor in the future. Process parameters are optimized here using Taguchi method with the help of ‘MINITAB 18’. Finally, the experiment is conducted in optimized conditions at 30 mg/ml Sugarcane Bagasse Powder (SBP), 0.2 mg/ml Dye Degrading Bacteria-I (DDB I), 0.2 mg/ml PPD at 30 ^oC and pH 5 for 12 h, and then biotransformation was confirmed by toxicological studies. Though acetylation is the only pathway of detoxification of PPD is reported yet, substantial detoxification of PPD was observed without observing the signature of acetylated PPD in FTIR, and mass analysis. This study enlightens the alternate pathway for detoxification of PPD which can be used for the removal of PPD from the environment.