A novel two stages chemical activation of pinewood waste for removing organic micropollutants from water and wastewater.

ABSTRACT

The prevalent presence of pharmaceuticals in aquatic ecosystems underscores the necessity for developing cost-effective techniques to remove them from water. The utilization of affordable precursors in producing activated carbon, capable of rivaling commercial alternatives, remains a persistent challenge. The adsorption of diclofenac and ciprofloxacin onto a novel pinewood-derived activated carbon (FPWAC) was explored, employing a sequential activation process involving ammonium nitrate (NH4NO3) treatment followed by sodium hydroxide (NaOH) activation. The produced FPWAC was then thoroughly characterized by employing several techniques. The removal of diclofenac and ciprofloxacin in water and real wastewater effluent was examined in batch tests. The optimum removal conditions were an FPWAC dosage of 1 g L-1, pH 6, mixture concentration of 25 mg L-1, and a temperature of 25 °C. The FPWAC was able to remove both pharmaceuticals for up to six cycles, with more than 95% removal for water and 90% for wastewater in the first cycle. The adsorption performance fitted well with the non-linear Freundlich isotherm for both pollutants. The kinetics of adsorption of diclofenac followed a pseudo-first-order model, while ciprofloxacin showed adherence to the pseudo-second-order model. FPWAC proved its potency as a low-cost adsorbent for pharmaceutical removal from wastewater.