Phosphorus recovery from saturated samples of bauxite residue after their use as reactive filter material to treat wastewater
Résumé
Nowadays, non-renewable phosphorus (P) resources such as natural deposits of apatite rocks represents the main P source for industrial production of chemical fertilizers. Natural reserves of P will drastically decline during the next 2 decades as pointed out by international perspective studies [1,2]. Therefore, there is a need to identify alternative P sources for the fertilizer production industry. Today, there is a general consensus that P recovery from wastewater is a viable way to overcome the shortage of natural resources [3,4]. Moreover, P removal from wastewater can significantly reduce the supply of this nutrient into sensitive aquatic ecosystems such as rivers, lakes and lagoons, thus reducing the risk of eutrophication. Several international researchers have found that bauxite residue (a waste from the aluminum production industry) is an efficient sorbent material for P removal from wastewater [5,6]. P binding on bauxite residue is achieved by various mechanisms including precipitation, adsorption and/or complexation on its mineral surface. In the frame of a main research project that aims at developing the use of bauxite residue as reactive material to retain and recover P from wastewater, this study focuses on the development of a dynamic process of P extraction and concentration from P saturated samples of bauxite residue...