Ophiorrhiza mungos-Mediated Silver Nanoparticles as Effective and Reusable Adsorbents for the Removal of Methylene Blue from Water

Aklima A Akhi; Abid Hasan; Nakshi Saha; Sabbir Howlader; Sabonty Bhattacharjee; Kamol Dey; A K M Atique Ullah; Farhana Rumzum Bhuiyan; Ashok Kumar Chakraborty; Umme Sarmeen Akhtar; Md Aftab Ali Shaikh; Benu Kumar Dey; Samiran Bhattacharjee; Sumon Ganguli

doi:10.1021/acsomega.3c05992

Ophiorrhiza mungos-Mediated Silver Nanoparticles as Effective and Reusable Adsorbents for the Removal of Methylene Blue from Water

ACS Omega. 2024 Jan 15;9(4):4324-4338. doi: 10.1021/acsomega.3c05992. eCollection 2024 Jan 30.

Authors

Aklima A Akhi^{1

2}, Abid Hasan^{1

2}, Nakshi Saha^{1

2}, Sabbir Howlader^{1

2}, Sabonty Bhattacharjee³, Kamol Dey¹, A K M Atique Ullah⁴, Farhana Rumzum Bhuiyan⁵, Ashok Kumar Chakraborty⁶, Umme Sarmeen Akhtar⁷, Md Aftab Ali Shaikh⁷, Benu Kumar Dey⁸, Samiran Bhattacharjee³, Sumon Ganguli^{1

2}

Affiliations

¹ Department of Applied Chemistry and Chemical Engineering, University of Chittagong, Chattogram 4331, Bangladesh.
² Biomaterials Research Laboratory (BRL), Department of Applied Chemistry and Chemical Engineering, University of Chittagong, Chattogram 4331, Bangladesh.
³ Centre for Advanced Research in Sciences (CARS), University of Dhaka, Dhaka 1000, Bangladesh.
⁴ Nanoscience and Technology Research Laboratory, Atomic Energy Center, Bangladesh Atomic Energy Commission, Dhaka 1000, Bangladesh.
⁵ Laboratory of Biotechnology and Molecular Biology, Department of Botany, University of Chittagong, Chattogram 4331, Bangladesh.
⁶ Department of Applied Chemistry and Chemical Engineering, Islamic University, Kushtia 7003, Bangladesh.
⁷ Bangladesh Council of Scientific and Industrial Research (BCSIR), Dhanmondi, Dhaka 1205, Bangladesh.
⁸ Department of Chemistry and Pro-Vice-Chancellor (Academic), University of Chittagong, Chattogram 4331, Bangladesh.

Abstract

Green synthesis of silver nanoparticles (AgNPs) using a plant extract has attracted significant attention in recent years. It is found as an alternative for other physicochemical approaches because of its simplicity, low cost, and eco-friendly rapid steps. In the present study, Ophiorrhiza mungos (Om)-mediated AgNPs have been shown to be effective bioadsorbents for methylene blue (MB) dye removal (88.1 ± 1.74%) just after 1 h at room temperature in the dark from an aqueous medium for the first time. Langmuir and Freundlich isotherms fit the experimental results having the correlation coefficient constants R² = 0.9956 and R² = 0.9838, respectively. From the Langmuir fittings, the maximum adsorption capacity and adsorption intensity were found to be 80.451 mg/g and 0.041, respectively, indicating the excellent performance and spontaneity of the process. Taking both models under consideration, interestingly, our findings indicated a fairly cooperative multilayer adsorption that might have been governed by chemisorption and physisorption, whereas the adsorption kinetics followed the pseudo-second-order kinetics mechanism. The positive and low values of enthalpy (ΔH⁰ = 4.91 kJ/mol) confirmed that adsorption is endothermic and physical in nature; however, the negative free energy and positive entropy value (ΔS⁰ = 53.69 J/mol K) suggested that the adsorption is spontaneous. The biosynthesized adsorbent was successfully reused up to the fifth cycle. A proposed reaction mechanism for the adsorption process of MB dye onto Om-AgNPs is suggested. The present study may offer a novel finding such as an effective and sustainable approach for the removal of MB dye from water using biosynthesized Om-AgNPs as reusable adsorbents at a comparatively faster rate at a low dose for industrial applications.