The release of unprocessed or moderately treated industrial wastewater, especially from the textile industry, poses significant environmental challenges due to the elevated levels of pollutants such as dyes. This research investigates the use of agricultural waste, specifically Raw Melon Husk (RMH), for the elimination of two different dyes which are Methylene Blue (MB) and Rhodamine 6G (R6G) utilizing the adsorption technique. RMH was characterized using Fourier Transform Infrared Spectroscopy and Scanning Emission Microscopy. Various experimental parameters were optimized, including pH, adsorbent dosage, initial dye concentration, contact time, and temperature. Optimal conditions for Methylene Blue (MB) and Rhodamine 6G (R6G) dyes removal were determined to be at pH 7 and 6, dosage of 1 g/L and 20 g/L, concentration of 30 mg/L and 50 mg/L, and a contact time of 30 minutes and 10 minutes respectively. The adsorption capacity and percentage removal for MB and R6G are 1.1084 mg/g and 94.5% as well as 1.345 mg/g and 94.20% respectively. The Temkin isotherm model best described the equilibrium data (R² = 0.9966) for MB while Langmuir model with R² = 0.9857 fitted best for R6G suggesting a monolayer biosorption capacity of 1.200 mg/g. The kinetics of both dyes followed a pseudo-second-order model with R² of 0.996 and 0.9998 respectively which inferred that the process is diffusion controlled. Thermodynamic studies indicated that the adsorption process for both dyes were exothermic and spontaneous. The melon husk has successfully been used for removing methylene blue and Rhodamine 6G from model wastewater. This study contributed to achieve SDG goals 3 and 6.
Theresa et al. (Tue,) studied this question.