Ecofriendly adsorption and sensitive detection of Hg (II) by biomass-derived nitrogen-doped carbon dots: process modelling using central composite design.

Autor: Issa MA; Department of Oil and Gas Economics, College of Administrative and Financial Sciences, Imam Ja'afar Al-Sadiq University, Baghdad, Iraq. mohammed.abdullah@sadiq.edu.iq.; Department of Chemical and Environmental Engineering, Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor, Malaysia. mohammed.abdullah@sadiq.edu.iq., Zentou H; Division of Physical Sciences and Engineering, Advanced Membranes and Porous Materials Center, King Abdullah University of Science and Technology, Thuwal, Kingdom of Saudi Arabia., Jabbar ZH; Environmental Engineering Department, College of Engineering, University of Baghdad, Baghdad, Iraq., Abidin ZZ; Department of Chemical and Environmental Engineering, Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor, Malaysia., Harun H; Department of Chemical and Environmental Engineering, Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor, Malaysia., Halim NAA; Faculty of Chemical Engineering Technology, Universiti Malaysia Perlis, 02600, Arau Perlis, Malaysia., Alkhabet MM; Medical Instrumentation Technical Engineering, Al-Rasheed University College, Baghdad, Iraq., Pudza MY; Department of Chemical and Environmental Engineering, Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor, Malaysia.
Jazyk: angličtina
Zdroj: Environmental science and pollution research international [Environ Sci Pollut Res Int] 2022 Dec; Vol. 29 (57), pp. 86859-86872. Date of Electronic Publication: 2022 Jul 08.
DOI: 10.1007/s11356-022-21844-0
Abstrakt: In this study, luminescent bio-adsorbent nitrogen-doped carbon dots (N-CDs) was produced and applied for the removal and detection of Hg (II) from aqueous media. N-CDs were synthesized from oil palm empty fruit bunch carboxymethylcellulose (CMC) and urea. According to several analytical techniques used, the obtained N-CDs display graphitic core with an average size of 4.2 nm, are enriched with active sites, stable over a wide range of pH and have great resistance to photobleaching. The N-CDs have bright blue emission with an improved quantum yield (QY) of up to 35.5%. The effect of the variables including pH, adsorbent mass, initial concentration and incubation time on the removal of Hg (II) was investigated using central composite design. The statistical results confirmed that the adsorption process could reach equilibrium within 30 min. The reduced cubic model (R 2  = 0.9989) revealed a good correlation between the observed values and predicted data. The optimal variables were pH of 7, dose of 0.1 g, initial concentration of 100 mg/L and duration of 30 min. Under these conditions, adsorption efficiency of 84.6% was obtained. The adsorption kinetic data could be well expressed by pseudo-second-order kinetic and Langmuir isotherm models. The optimal adsorption capacity was 116.3 mg g -1 . Furthermore, the adsorbent has a good selectivity towards Hg (II) with a detection limit of 0.01 μM due to the special interaction between Hg (II) and carboxyl/amino groups on the edge of N-CDs. This work provided an alternative direction for constructing low-cost adsorbents with effective sorption and sensing of Hg (II).
(© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)
Databáze: MEDLINE
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