Ciprofloxacin removal from aqueous solutions by granular ferric hydroxide: Modeling and optimization

Granular ferric hydroxide is a good commercial adsorbent used to remove various impurities in aqueous systems. Ciprofloxacin is known as an emerging pollutant in aquatic environment. To understand the adsorption process of ciprofloxacin by GFH, this study evaluates the performance of GFH using response surface methodology. The effects of pH, initial ciprofloxacin concentration, adsorbent dose and contact time on the adsorption rates of ciprofloxacin were investigated. The results of optimization of the variables derived in the initial pH = 7.5, ciprofloxacin concentration, were 6.05 mg. L-1, adsorbent dosage = 1.39 g. L-1 and contact time = 27.5 min, maximum removal efficiency of 42.31% and desirable 0.987. According to RSM, this study follows the quadratic model (R2 = 0.969). Considering the aspects of good quality, economic efficiency and feasibility, adsorption with GFH is recommended as a successful pretreatment for the removal of ciprofloxacin from various aqueous solutions.