Low temperature adsorption of nitrate in water by ammoniac-grafted iron-based biochar: Electrostatic interaction and surface complexation

Abstract

Since organic matter and ammonia in wastewater have been effectively controlled in recent years, nitrate nitrogen has progressively emerged as one of the most important yet challenging to measure markers of water quality. Scientists are trying to create materials for water treatment that are safe, affordable, and efficient. In order to create the new adsorbent Fe-TBC, maize stover charcoal (BC) was impregnated with ferric chloride and subsequently grafted with triethylamine. The findings demonstrated that the ammonia grafting produced a greater positive charge, the iron impregnation expanded the surface area of BC, and the charcoal fibers exhibited a rich pore structure. Numerous characterization analyses verified the effective synthesis of Fe-TBC, and experimental demonstration and characterization studies delved into the adsorption mechanism of Fe-TBC on nitrate. Fe-TBC's adsorption rate on nitrate was enhanced, and it continued to have a superior adsorption impact at lower temperatures, according to adsorption kinetics and isotherm investigations. When the concentration of interfering ions is the same, the removal efficiency of nitrate by Fe-TBC decreased by less than 20 %. These findings indicate that Fe-TBC is a new type of environmentally friendly low temperature selective adsorbent with high application value.