abstract
In this study novel porous biomass fly ash-containing geopolymer monoliths were produced using a simple and flexible procedure. Geopolymers exhibiting distinct total porosities (ranging from 41.0 to 78.4%) and low apparent density (between 1.21 and 0.44 g/cm(3)) were fabricated. Afterwards, the possibility of using these innovative materials as lead adsorbents under distinct conditions was evaluated. Results demonstrate that the geopolymers' porosity and the pH of the ion solution strongly affect the lead adsorption capacity. Lead adsorption by the geopolymer monoliths ranged between 0.95 and 6.34 mg(lead/geopolymer). More porous geopolymers presented better lead removal efficiency, while higher pH in the solution reduced their removal ability, since metal precipitation is enhanced. These novel geopolymeric monoliths can be used in packed beds that are easily collected when exhausted, which is a major advantage in comparison with the use of powdered adsorbents. Furthermore, their production encompasses the reuse of biomass fly-ash, mitigating the environmental impact associated with this waste disposal, while decreasing the adsorbents production costs. (C) 2016 Elsevier B.V. All rights reserved.
keywords
AQUEOUS-SOLUTION; REMOVAL; METAKAOLIN; IONS; EQUILIBRIUM; BIOMASS; BIOSORPTION; ADSORBENT; SPHERES; CHAFF
subject category
Engineering; Environmental Sciences & Ecology
authors
Novais, RM; Buruberri, LH; Seabra, MP; Labrincha, JA
our authors
João António Labrincha Baptista
Full professor
Leire Hernando Buruberri
PhD Student
Maria Paula Seabra
Assistant Professor
Rui Miguel Novais
Assistant Professoracknowledgements
This work was developed within the scope of the project CICECO-Aveiro Institute of Materials, POCI-01-0145-FEDER-007679 (FCT Ref. UID/CTM/50011/2013), financed by national funds through the FCT/MEC and when appropriate co-financed by FEDER under the PT2020 Partnership Agreement. The authors acknowledge the assistance of Dr. R.C.Pullar with editing English language in this paper.