Abstract:
Nanoscale zero-valent iron (nZVI), together with a biochar (BC) support, provides
advantageous materials for wastewater purification via adsorption, reduction,
complexation and advanced oxidation mechanisms. Fabricating the materials can be
done via two production routes: nZVI loaded BC subjected to subsequent
carbothermal reduction (BC-nZVI) and nZVI loaded biomass (BM) subjected to
synchronous pyrolysis and carbothermal reduction (BM-nZVI). Nonetheless, the
physicochemical characteristics and the remediation capability of the two materials
have not been comparatively evaluated. The present study focuses on preparing and
extensively characterizing these materials with subsequent comparative analysis of
remedial action. Surface morphology, functionality, elemental composition and point
of zero charge were evaluated. XRD peak pattern confirmed the formation of zero-valent iron and the nano-scale was confirmed by TEM. Synergistic adsorptive and
degradative behavior of the materials towards p-nitroaniline (pNA) and p-nitrophenol
(pNP) were studied by evaluating the optimum pH, which was pH 3.0, contact time
of 180 minutes and isotherm patterns. Higher initial adsorption capacity was observed
in BM-nZVI while more sustainability and stability over the regeneration cycles were
portrayed by BC-nZVI. Therefore, it is conclusive that materials produced through
both synchronous and asynchronous routes have signature advantages in purifying
pNA and pNP contaminated water.
