Reactive phosphorus removal from aquaculture and poultry productions systems using polymeric hydrogels

This work reports on the features of a sorption processes for the ultimate removal and recovery of reactive phosphorus from aquaculture and poultry production wastewater effluents. The sorbent used was a cross-linked polyamine (PAA-HCl) polymeric hydrogel. The PAA-HCl hydrogels were prepared by chemically cross-linking aqueous solutions of linear PAA-HCl chains with epichlorohydrin (EPI). The phosphorus binding capacity of the gels was measured in standard aqueous solutions as a function of ionic strength. Equilibrium PO4(3-), loadings of 100 mg anion/g gel were obtained. The regeneration ability of the gels was demonstrated by release of the bound phosphorus anions upon washing with 1-2 M NaOH solution, providing opportunities to recover and reuse the gel over multiple cycles. The ionic polyamine gels have been demonstrated to be appropriate materials for treating poultry and aquaculture wastewater effluents. Upon treatment phosphorus anion concentrations were reduced to levels suitable for discharge into natural surface waters.