Optimization of the Adsorption Performance of Herbal Residues as Lanthanide Ion-Modified Carriers for Phosphate by Fly Ash and its Application

Abstract

AbstractIn order to mitigate the harmful effects of eutrophication in water bodies, the use of lanthanide-based modified materials for phosphate removal from wastewater has attracted much attention. Unlike conventional inorganic adsorbents, plant wastes usually have poor adsorption performance and difficulty in resolving phosphate for reuse due to smaller pore size and difficulty in uniform loading of modified ions. In this paper, a composite adsorbent (LC-MM) was synthesized by hydrothermal synthesis with loading lanthanum carbonate from waste traditional Chinese medicine (MM) and co-heating treatment with fly ash (CFA), which was applied to the removal of phosphate from water. The results showed that LC-MM maximum adsorption capacity of 52 mg g-1, it showed appreciable adsorption capacity to phosphate on agricultural wastewater in the presence of complex interfering ions and in urban surface waters with low phosphate concentrations. Five adsorption-desorption cycles showed good reusability. The mechanism study showed that the magnetic metal ions Fe3+, Al3+, Mg2+ Ca2+ introduced in CFA made the La3+ ions more uniformly distributed on the surface of the adsorbent. The ligand exchange between phosphate and carbonate, the internal spherical complexation formed by lanthanum ion and phosphate, and surface chemical precipitation attachment are the main reasons why the adsorption capacity of LC-MM approached or even surpassed that of conventional lanthanum-modified synthetic inorganic material adsorbents. In conclusion, this is an effective method for optimizing the modification of plant material

Keywords: Keywords: lanthanum carbonate, hydrothermal synthesis and co-heating, modified plant adsorbents, utilization of waste materials