Pilot-Scale Treatment of Sunfix Red Dye Wastewater using MBBR with UV Fenton: Optimization using BBD- RSM With Economic Analysis

Abstract

The textile industry is one of the world's most profitable manufacturing sectors. Increased consumer demand has led to proportional growth in textile mill operations and wastewater generation. These textile industries employ hazardous synthetic dyes, which pose environmental and health risks. Consequently, the development of effective technologies for dye degradation in textile wastewater is imperative. This work has investigated the application of biological treatment, such as moving bed biofilm reactor (MBBR), with chemical treatment, such as UV/Fenton's reaction, for effective degradation of Sunfix red spd dye (SR). The Box-Behnken statistical experimental design was used to optimize the degradation of SR dye. Furthermore, the integrated MBBR-UV/Fenton system showed very high removal efficiencies, decreasing color by > 98%, Chemical Oxygen Demand (COD) by 84-88%, Biological Oxygen Demand (BOD₅) by > 98%, and ammoniacal nitrogen (NH₄-N) by 70-75%. Similar results were observed when the system was scaled up to 1000 L/d, wherein the system reduced color by 98.89%, COD by 94.97%, BOD₅ by 94.63%, and NH₄-N by 79.91%. Additionally, HPLC analysis validated the disappearance of the parent compound, confirming dye degradation using the MBBR-UV/Fenton system. Thus, the combination of both MBBR and UV/Fenton processes showcases a highly effective and promising solution for textile wastewater treatment.