A novel bentonite-humic acid composite material Bephos~(TM) for removal of phosphate and ammonium from eutrophic waters

摘要

A novel low-cost composite material was prepared (Bephos~(TM)) by embedding Fe, Cu ions and humic acid using in the interlayer space of a natural bentonite. Bench-scale batch experiments were performed to examine its efficiency as adsorbent for phosphate and ammonium removal from natural waters. Phosphate and ammonium uptake was evaluated vs. pH in adsorption kinetics and adsorption isotherms. The effect of salinity (fresh, brackish and marine waters) and adsorption thermodynamics were also investigated. Bephos~(TM) exhibits higher adsorption than other pertinent materials. Moreover Bephos~(TM) is cable for simultaneous adsorption of both phosphorus and ammonia and this is an important advantage against other materials used to restore eutrophic water bodies. The maximum phosphate and ammonium adsorption capacities were 26.5 mg/g and 202.1 mg/g respectively. Bephos~(TM) can function efficiently within a wide range of pH, e.g. 5-9. Adsorption kinetics showed that more than 90% and 70% removal of phosphate and ammonium respectively from water within 30 min. Bephos~(TM) is potent for remediation of phosphate and ammonium at low concentrations that occur in natural water ecosystems.