Ammonia removal by adsorptive clinoptilolite ceramic membrane: Effect of dosage, isothermal behavior and regeneration process

Abstract

This work investigates the effectiveness of ammoniacal nitrogen (NH4+-N) removal from contaminated water by adsorptive hollow fiber ceramic membrane (HFCM) derived from naturally made clinoptilolite. The technological value of this work is the simple mechanism of the adsorptive HFCM in removing gaseous ammonia in water by combining adsorption and separation. To test the technical feasibility of this proposed technology, clinoptilolite HFCM was fabricated via phase inversion-based extrusion/sintering technique and characterized by SEM and water permeation flux. The produced HFCM corresponds to the desired morphology of the asymmetric structure (dense and void formations) with outstanding adsorption performance of NH4+-N. The effects of the HFCM’s operational parameters on its removal are examined in terms of membrane dosage and isothermal studies. The adsorption isotherm behavior exhibited that the adsorption process fitted the Freundlich isotherm model with outstanding removal performance even at trace concentration of ammonia. The low amount used by HFCM (4.75×10-4 m2) resulted in over 96% ammonia removal, indicating a low cost of adsorption process. The regeneration of saturated HFCM suggests an outstanding recovery of the HFCM for its subsequent use for NH4+-N removal. This study also reveals the potential of adsorptive HFCM as a simple and cost-effective technology for ammonia removal from wastewater.