Insight into biosorptive uptake of fluoride by chemically activated biochar: experimental modeling and parametric optimization

The present study aims to introduce a proficient and inexpensive adsorbent for eliminating fluoride from an aqueous medium. The defluoridation process was carried out by activated carbon derived from mango kernel (MKA), which is naturally available bio-waste. The adsorption process was first modeled by an artificial neural network (ANN) and then optimized through a genetic algorithm (GA). The concentration profile was also validated by computational fluid dynamics (CFD). Impacts of input parameters viz. contact duration, pH, temperature, adsorbent dose, and initial concentration on percent removal were observed. Surface morphologies, active surface area, presence of functional groups, etc. of MKA were characterized using BET, SEM, EDX, and FTIR, respectively. The engineered sorbent confirms excellent performance towards expulsion of fluoride ions with above 99% removal at an initial concentration of 9 mg/L, MKA dose of 0.3 g/L, temperature 25 degrees C, pH 5, and contact time of 18 h. The adsorption process was proved to be thermodynamically spontaneous and obeys pseudo-2nd-order kinetic and Freundlich isotherm model. Therefore, it can be concluded that MKA could be a promising precursor for developing adsorbents on the way to fluoride decontamination in an aqueous solution.

Automated summary

This study introduces the use of activated carbon derived from mango kernel as an adsorbent for removing fluoride from water. The adsorption process was modeled and optimized using artificial neural network and genetic algorithm, and the results were validated using computational fluid dynamics. The experimental results showed that the mango kernel activated carbon exhibited excellent performance in removing fluoride ions.