TY - JOUR
TI - Phosphorus and potassium recovery from anaerobically digested olive mill wastewater using modified zeolite, fly ash and zeolitic fly ash: a comparative study
AU - Mitrogiannis, D.
AU - Psychogiou, M.
AU - Manthos, G.
AU - Tsigkou, K.
AU - Kornaros, M.
AU - Koukouzas, N.
AU - Michailidis, D.
AU - Palles, D.
AU - Kamitsos, E.I.
AU - Mavrogonatos, C.
AU - Baziotis, I.
JO - Journal of Chemical Technology and Biotechnology
PY - 2022
VL - null
TODO - null
SP - null
PB - John Wiley and Sons Ltd
SN - null
TODO - 10.1002/jctb.7059
TODO - Bacteria;  Desorption;  Fly ash;  Ion exchange;  Phosphorus;  Potassium;  Precipitation (chemical);  Recovery;  Scanning electron microscopy;  Soils;  Wastewater treatment;  Zeolites, Adsorption and desorptions;  Adsorption capacities;  Circular economy;  Comparatives studies;  Incubation time;  Lignite fly ash;  Modified zeolite;  Nutrient recovery;  Olive-mill waste-waters;  Plant availability, Adsorption
TODO - BACKGROUND: Nutrient recovery from wastewater is gaining attention in the frame of circular economy. In this study, Ca(OH)2-treated zeolite (CaT-Z), lignite fly ash (FA) and zeolitic fly ash (ZFA) were primarily used to adsorb phosphate phosphorus (PO4-P) from anaerobically digested olive mill wastewater (ADOMW). The simultaneous recovery of potassium (K) was also examined based on adsorption and desorption data. The fractionation of adsorbed P was determined as an important parameter for its plant availability. RESULTS: More P was adsorbed from ADOMW on ZFA and FA (up to 4.35 and 5.21 mg g−1, respectively) than on CaT-Z (2.62 mg g−1). An increased P adsorption on ZFA and FA was observed between incubation times of 7 and 14 days. The sequential desorption procedure verified the trend of P adsorption capacities and showed that the plant-available P (NaHCO3-P) amounted to 1.34, 2.34 and 1.69 mg g−1 CaT-Z, ZFA and FA, respectively. After 14 days, CaT-Z and ZFA adsorbed much more K (19.2 and 20.5 mg g−1, respectively) than FA (4.3 mg g−1). The desorption of exchangeable K confirmed this difference. Scanning electron microscopy–energy dispersive spectrometry analyses indicated P adsorption and surface precipitation as Ca–P phases as well as K+ for Ca2+ ion exchange on the loaded adsorbents. CONCLUSIONS: ZFA was more efficient for dual adsorption combining the properties of the zeolitic fraction (enhanced K adsorption) and pristine FA (P adsorption on Ca-bearing phases). The sufficient concentrations of plant-available P and K on the three adsorbents suggest their potential use as soil amendments. © 2022 Society of Chemical Industry (SCI). © 2022 Society of Chemical Industry (SCI).
ER -