title: Innovative approach for recycling phosphorous from agro-wastewaters using water treatment residuals (WTR).
abstract: Phosphorus capture from polluting streams and its re-use using industrial byproducts has the potential to also reduce environmental threats. An innovative approach was developed for P removal from soil leachate and dairy wastewater using Al-based water treatment residuals (Al-WTR) to create an organic-Al-WTR composite (Al/O-WTR), potentially capable of serving as a P fertilizer source. Al-WTR was mixed with either soil leachate, or with dairy wastewater, both of which contained elevated P concentrations (e.g., 7.6-43.5 mg SRP L-1). The Al-WTR removed ∼95% inorganic P, above 80% organic P, and over 60% dissolved organic carbon (DOC) from the waste streams. P removal was correlated with P concentration in the waste streams and was consistent with an increase in Al/O-WTR P content as determined by X-ray fluorescence (XRF) and surface analysis using scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS). Organic C was a major constituent in the original Al-WTR (31.4%) and increased by 1% in the Al/O-WTRs. Organic C accumulation on particles surfaces possibly enhanced weak P bonding. Desorption experiments indicated an initial and substantial P release (30 mg SRP kg-1Al/O-WTR), followed by relatively constant low P solubility (ca. 10 mg kg-1). Organic C was continuously released to the solution (over 8000 mg kg-1), concomitantly with Ca and other electrolytes, possibly indicating dissolution from inner pores, accounting for the highly porous nature of the Al-WTR, evident by SEM images. The potential of P-loading on Al/O-WTR to promote P recycling should be further studied.
authors: MIGAL - Galilee Research Institute, Hydro-Geochemistry Laboratory, Kiryat Shmona 11016, Israel; University of Haifa, Dr. Moses Strauss Department of Marine Geosciences, Leon H. Charney School of Marine Sciences, University of Haifa, Haifa 31905, Israel. Electronic address: irisz2910@gmail.com.
authors: Iris
authors: I
authors: Zohar
authors: Department of Soil and Crop Sciences, C127 Plant Sciences Bldg, Colorado State University, Fort Collins, CO 80523-1170, USA.
authors: James A
authors: JA
authors: Ippolito
authors: Department of Earth & Environmental Sciences, California State University East Bay, 25800 Carlos Bee Blvd, Hayward, CA 94542, USA.
authors: Michael S
authors: MS
authors: Massey
authors: MIGAL - Galilee Research Institute, Hydro-Geochemistry Laboratory, Kiryat Shmona 11016, Israel.
authors: Iggy M
authors: IM
authors: Litaor
mesh_terms: D000327:Adsorption; D000535:Aluminum / Q000032:analysis; D004573:Electrolytes / Q000032:analysis; D005308:Fertilizers / Q000032:analysis*; D006878:Hydroxides / Q000032:analysis; D008855:Microscopy, Electron, Scanning; D009930:Organic Chemicals / Q000032:analysis; D010758:Phosphorus / Q000032:analysis*; D056951:Photoelectron Spectroscopy; D059027:Recycling / Q000379:methods; D012987:Soil; D012995:Solubility; D013499:Surface Properties; D062065:Wastewater / Q000032:analysis*; D014874:Water Pollutants, Chemical / Q000032:analysis*; D018508:Water Purification / Q000379:methods*
chemical_list: D000535:Aluminum; D004573:Electrolytes; D005308:Fertilizers; D006878:Hydroxides; D009930:Organic Chemicals; D010758:Phosphorus; D012987:Soil; D062065:Wastewater; D014874:Water Pollutants, Chemical
keywords: Agro-wastewater; Aluminum-water treatment residuals; DOC impact on P binding; Inorganic phosphorus sorption; Organic phosphorus sorption; Phosphorus recycling