Efficient recovery and recycling of phosphorus from sewage sludge by using zirconium sulfate-surfactant micelle mesostructure

Phosphorus (P) is one of the major elements for plants and food production. However, P is limited resource in the world.
The zirconium sulfate-surfactant micelle mesostructure (ZS) greatly and selectively adsorb phosphate ions with anion exchange in the solutions (Fig. 1). Furthermore, P adsorbed to ZS is easily desorbed by NaOH or citric acid solutions.
In this study, efficient recovery and recycling of P from sewage sludge are performed by using ZS.

Two scenarios are proposed by using ZS (Fig. 2). In Scenario (1), P is eluted from sewage sludge by the disposal of anaerobic digestion and adsorbed to ZS, and then, the ZS adsorbing P (ZP) is utilized as P fertilizer. In Scenario (2), concentrated P solution generated by anaerobic digestion of the sludge is efficiently recovered as calcium phosphates, and then, they are utilized as P fertilizer.