Parametric optimization of aloe vera coagulant for nitrate removal from textile wastewater using response surface methodology (RSM)

Abstract

Textile production wastewater's composition has been an issue since it contains organic material and inorganic pollutants, making treatment difficult. This study used aloe vera as a natural coagulant to remediate wastewater. This objective was to use response surface methods to optimize operating parameters on the removal efficiency of nitrate removal through the application of response surface methodology (RSM). The influence of four factors such as aloe vera dosage, agitation time, agitation speed, and settling time on the removal of nitrate was examined to determine the optimal conditions for water treatment. The selected range of operating parameters is 20–40 min agitation time, 60–120 min settling time, a dosage of 0.5–1.5 g/L, and an agitation speed of 150–250 rpm respectively. Validation was carried out on the acquired data using the quadratic model. The optimal conditions for achieving the highest nitrate removal were determined as follows: 20 min agitation time, settling time of 120 min, 0.5 g/L dosage of aloe vera and 150 rpm agitation speed. The established conditions were confirmed through replication, resulting in 97% removal of nitrate. Functionalized groups that cause coagulation were revealed by Fourier-transform infrared spectroscopy (FTIR) and a firm, dense structure shown by scanning electron microscopy analysis suggested that contaminants had adhered to the coagulant. The findings of this research have potential practical applications on an industrial scale for water treatment purposes.