Using hydrogel-biochar composites for enhanced cadmium removal from aqueous media
Publication Type:
Journal
Authors:
Year Published:
2018
Abstract:
Cadmium (Cd) is a common heavy metal and is often released into aquatic environment
during mining activities and metallurgical processes. At high concentrations, Cd is
highly toxic to most organisms and can be accumulated in organisms before entering
human body through food chains. Many technologies have been developed to
remediate Cd contamination, among which biochar is one of the most sustainable
and promising. However, high pricing of biochar today is plaguing its large-scale
applications. Therefore, in this study, inexpensive acrylamide was used to synthesize
polyacrylamide hydrogel-biochar composites with the dosages of 1, 3 and 5% weight
ratios of biochar. The swelling ratio significantly increased from 818% for untreated
hydrogel to 1220, 1349 and 1506% for composites with increasing dosages of biochar,
respectively. According to the isotherm experiment results, modeling simulations
indicated that the maximum adsorption capacities (qmax) of the composites were
30.63, 59.21 and 63.58 mg/g for the three composites with increasing biochar dosages,
respectively. In comparison, the untreated hydrogel had a much lower qmax of 24.72
mg/g. Besides the greater water swelling capacity, the significantly improved ability
of hydrogel-biochar composites to entrap Cd from aqueous media was hypothetically
attributed to the formation of ionic attraction fields around scattered biochar particles.
It was recommended that 3% of biochar be the optimal dosage because further
improvement became insignificant at higher dosages. The use of hydrogel-biochar
composites for Cd contamination issues is a cost-effective approach.
Journal:
Material Science & Engineering International Journal
Volume:
2
Issue:
6
Pagination:
294-298
ISSN:
Short Title:
Date Published:
12/31/2018