Co-Authors:
Rabinovich, A., Department of Earth and Environmental Sciences, Rutgers University, 101 Warren Street, Newark, NJ, United States
Rouff, A.A., Department of Earth and Environmental Sciences, Rutgers University, 101 Warren Street, Newark, NJ, United States
Lew, B., Institute of Agricultural Engineering, ARO Volcani Center, P.O. Box 6, Bet Dagan, Israel
Ramlogan, M.V., Department of Earth and Environmental Sciences, Rutgers University, 101 Warren Street, Newark, NJ, United States
Abstract:
An aerated fluidized bed reactor (aerated-FBR) was used for recovery of orthophosphate (PO4-P) from dairy wastewater (D-WW) and swine wastewater (S-WW) by struvite (MgNH4PO4·6H2O) precipitation. Model wastewater solutions (S-model, D-model) free of organic material were also treated. The maximum PO4-P recovery for treated livestock wastes was 94% for S-WW and 63% for D-WW. The PO4-P recovery did not improve for S-model compared to S-WW, but increased to 81% for D-model relative to D-WW, suggesting that the high organic content of D-WW may hinder the recovery process. X-ray diffraction (XRD) analysis of recovered solids revealed that treated S-WW produced mostly struvite (95-98%) while D-WW yielded a mixture of struvite (28-33%), calcite (CaCO3; 17-55%), and monohydrocalcite (CaCO3·H2O; 13-42%). The Fourier transform infrared (FTIR) spectra of the solids confirm the presence of vibrational bands associated with these minerals. Simultaneous thermal analysis (STA) indicated that all solids, except for D-WW, show thermogravimetric (TG) trends consistent with the struvite and calcium carbonate content. The D-WW solids had additional TG steps, possibly due to high organic and colloidal content, and slightly improved ammonium stability. The aerated-FBR treatment is an effective method to reduce PO4-P from livestock wastewater through precipitation of pure struvite and struvite/calcium carbonate mixtures. © 2017 American Chemical Society.