There has been a lot of attention on water pollution by dyes in recent years because of their serious toxicological implications on human health and the environment. Therefore, the current study presented a novel polyethylene glycol-functionalized graphene oxide/chitosan composite (PEG-GO/CS) to remove dyes from aqueous solutions. Several characterization techniques, such as SEM, TEM, FTIR, TGA/DTG, XRD, and XPS, were employed to correlate the structure–property relationship between the adsorption performance and PEG-GO/CS composites. Taguchi’s (L25) approach was used to optimize the batch adsorption process variables [pH, contact time, adsorbent dose, and initial concentration of methyl orange (MO)] for maximal adsorption capacity. pH = 2, contact time = 90 min, adsorbent dose = 10 mg/10 mL, and MO initial concentration = 200 mg/L were found to be optimal. The material has a maximum adsorption capacity of 271 mg/g for MO at room temperature. With the greatest R2 = 0.8930 values, the Langmuir isotherm model was shown to be the most appropriate. Compared to the pseudo-first-order model (R2 = 0.9685), the pseudo-second-order model (R2 = 0.9707) better fits the kinetic data. Electrostatic interactions were the dominant mechanism underlying MO sorption onto the PEG/GO-CS composite. The as-synthesized composite was reusable for up to three adsorption cycles. Thus, the PEG/GO-CS composite fabricated through a simple procedure may remove MO and other similar organic dyes in real contaminated water.
This content will become publicly available on June 28, 2025
Optimization of batch and packed-bed column Cr( vi ) adsorption of an amine-rich chitosan/polyethyleneimine composite: application in electroplating wastewater treatment
Toxic oxyanions of Cr(VI) can be potentially removed by adsorbents with positively charged surfaces. In this
study, we synthesized a stable and insoluble amine-rich polymer composite (CS–PEI–GLA) by crosslinking
polyethyleneimine (PEI), a soluble amine-rich synthetic polymer, and chitosan (CS) with glutaraldehyde
(GLA). The positively charged amine groups were the main adsorption sites. The batch investigation
demonstrated that the adsorbent was able to remove ≥90% of chromium at pH ranging from 2 to 8. Due
to deprotonation of the amine groups, chromium removal decreased at higher pH values. The adsorption
was fast and reached equilibrium after 45 min. The maximum adsorption capacity was 500 mg g−1
according to the Langmuir isotherm and did not decrease in the presence of monovalent anions. In the
column study, the adsorption capacity was the highest when the flow rate was the lowest (5 mL min−1),
influent concentration was medium (225 mg L−1), and the bed height was the shortest (3.5 cm). NaOH was
the best recovery reagent with recovery of 67% in batch and 31% in the column. The CS–PEI–GLA
composite was able to remove 97.1 ± 0.1% chromium in batch and treat 750 mL of electroplating
wastewater with a 3.5 cm packed-bed column.
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- Award ID(s):
- 1904472
- PAR ID:
- 10519973
- Publisher / Repository:
- RSC
- Date Published:
- Journal Name:
- Environmental Science: Water Research & Technology
- Volume:
- 10
- Issue:
- 7
- ISSN:
- 2053-1400
- Page Range / eLocation ID:
- 1572 to 1585
- Subject(s) / Keyword(s):
- Chitosan Polyethyleneimine Chromium Batch adsorption Packed bed column
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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