Production of fired clay bricks as a safe removal method for spent adsorbents from sunflower and corn residues

SIMÓN, DAIANA; GASS, SEBASTIÁN; QUARANTA, NANCY; CRISTÓBAL, ADRIÁN

JOURNAL OF CLEANER PRODUCTION

ELSEVIER SCI LTD

Año: 2023

0959-6526

Heavy metals adsorption from lignocellulosic waste is a promising technology for wastewater treatment. Although studies on this alternative technology are increasing innumber, information on the management of spent adsorbents (potential sources ofcontamination) is scarce. In this study, the stabilization of sunflower seed hulls and corn residues used as adsorbents of heavy metals in fired clay bricks as building materials is proposed. The solid bricks were molded by uniaxial compression and fired at 950 °C. The specimens presented excellent heavy metal retention efficiencies, and the evaluation of physical and mechanical properties showed differences according tobiomass but no effect associated with heavy metals at the concentrations used. In thefired bricks, the biomasses served to form pores (increasing porosity by +35 and +46%), beneficial due to the low weight and hypothetical insulating capacity of the products. However, the bricks´ quality and mechanical performance of the bricks decreased compared to the control samples. Mechanical tests showed that bricks with corn were better than bricks with sunflower (compressive strength > 7 MPa). The findings presented here can be considered as a starting point in the safe disposal of spent adsorbents of lignocellulosic origin, with reuse as pore formers in construction bricks.