title: Phosphate separation and recovery from wastewater by novel electrodialysis.
abstract: Stimulated by the depletion of phosphate resources, phosphate recovery systems have been studied in recent years. The use of struvite reactors has proven to be an effective phosphate recovery process. However, the struvite reactor effluent still consists of an excessive amount of phosphate that cannot be recovered nor can be directly discharged. In this study, selectrodialysis (SED) was used to improve the efficiency of phosphate recovery from a struvite reactor: SED was implemented in such a way that phosphate from the effluent of an USAB (upflow anaerobic sludge blanket) reactor was transferred to the recycled effluent of a struvite reactor. Prior to the experiments, synthetic water with chloride and phosphate was used to characterize the efficiency of SED for phosphate separation. Results indicate that SED was successful in concentrating phosphate from the feed stream. The initial current efficiency reached 72%, with a satisfying (9 mmol L(-1)) phosphate concentration. In the experiments with the anaerobic effluent as the phosphate source for enrichment of the effluent of the struvite reactor, the phosphate flux was 16 mmol m(-2) h(-1). A cost evaluation shows that 1 kWh electricity can produce 60 g of phosphate by using a full scale stack, with a desalination rate of 95% on the feed wastewater. Finally, a struvite precipitation experiment shows that 93% of phosphate can be recovered. Thus, an integrated SED-struvite reactor process can be used to improve phosphate recovery from wastewater.
authors: Department of Chemical Engineering, Process Engineering for Sustainable Systems, KU Leuven, W. de Croylaan 46, B-3001 Leuven, Belgium. yang.zhang@vito.be
authors: Yang
authors: Y
authors: Zhang
authors: Evelyn
authors: E
authors: Desmidt
authors: Arnaud
authors: A
authors: Van Looveren
authors: Luc
authors: L
authors: Pinoy
authors: Boudewijn
authors: B
authors: Meesschaert
authors: Bart
authors: B
authors: Van der Bruggen
mesh_terms: D000693:Anaerobiosis; D003956:Dialysis / Q000379:methods*; D004867:Equipment Design; D017616:Magnesium Compounds; D010710:Phosphates / Q000302:isolation & purification*; D000069877:Struvite; D014865:Waste Disposal, Fluid / Q000295:instrumentation / Q000379:methods*; D062065:Wastewater / Q000737:chemistry*
chemical_list: D017616:Magnesium Compounds; D010710:Phosphates; D000069877:Struvite; D062065:Wastewater