Browsing by Author "Rubertelli, Giorgia"
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Item Open Access Demonstration of ion exchange technology for phosphorus removal and recovery from municipal wastewater(Elsevier, 2021-04-20) Guida, Samuela; Rubertelli, Giorgia; Jefferson, Bruce; Soares, AnaOrthophosphate (PO4-P) removal and recovery from municipal wastewater were investigated in a 10 m3/day hybrid anion exchanger (HAIX) demonstration plant. To date, HAIX resins have been investigated for PO4-P removal at laboratory scale with promising results but there is a need to investigate the application of the technology at larger scale, over extended operation whilst establishing an efficient regenerant management solution. The HAIX removed an average of 6 mg PO4-P /L to >0.3 mg PO4-P/L, within 430 bed volumes, with a capacity of 4.1 mg PO4-P/g resin. To manage the regenerant (NaOH 2%) efficiently, this was reused up to 8 times, reaching 785 mg PO4-P/L, but the adsorption capacity was compromised, and it decreased to 1.5 mg PO4-P/g resin. By adding calcium hydroxide to the saturated NaOH, 95% of the PO4-P was recovered as hydroxyapatite, and at the same time the regeneration effectiveness was re-established, as <0.3 mg PO4-P/L was reached again in the effluent. The treated NaOH was reused as regenerant solution, ensuring high effluent quality of <0.2 mg PO4-P/L. This study confirmed the capability of HAIX technology to remove and recover PO4-P from wastewater offering a solution which ensures both a high effluent quality and a circular economy approach.Item Open Access Regeneration and modelling of a phosphorous removal and recovery hybrid ion exchange resin after long term operation with municipal wastewater(Elsevier, 2021-07-16) Pinelli, Davide; Bovina, Sara; Rubertelli, Giorgia; Martinelli, Andrea; Guida, Samuela; Soares, Ana; Frascari, DarioAdsorption represents one of the most promising process for phosphorous (P) removal and recovery from municipal wastewater, but questions about its long-term stability remain. The goals of this work were (i) to assess changes in morphology and adsorption performances of hybrid anion exchanger (HAIX) LayneRT after 2.5 years of operation in a 10 m3 d−1 demonstration plant fed with secondary-treated municipal wastewater, (ii) to optimize the LayneRT regeneration procedure, and (iii) to evaluate the suitability of the ion exchange model to describe P adsorption on LayneRT. LayneRT is composed of hydrated ferric nanoparticles dispersed in a strong base anion exchange resin. Batch and continuous flow adsorption/desorption tests were conducted with the resin used for 2.5 years, regenerated with two alternative solutions: NaOH, reactivating mainly the iron nanoparticles active sites, and NaOH + NaCl, also regenerating the active sites of the ion exchange media. The physicochemical characterization by Scanning Electron Microscope indicated that regeneration by NaOH significantly reduced the deterioration of the resin surface, even after 59 adsorption/desorption cycles. Lab-scale continuous flow tests showed that the resin regenerated with either solution featured P adsorption performances very close to that of the virgin resin. The isotherm tests showed that P adsorption by LayneRT was effectively simulated with the ion exchange model. This study confirms that LayneRT is a durable, resistant and promising media for P recovery from wastewater.