Montmorillonite based copper oxide nanoparticles for the efficient remediation of phosphate and anti-bacterial activity against gram-negative bacteria

ABSTRACT

The present work describes the potential applications of Montmorillonite-derived Copper Oxide Nanocomposite (MMT-CuONC) which was prepared via a chemical reduction method using clay Montmorillonite (MMT K10) as a stabilizing agent. The nanocomposite effectively and efficiently removed PO₄^3- from the aqueous solution with maximum removal of 89.2% in 40 min. SEM-EDX analysis confirmed the adsorption of phosphate onto the surface of the nanocomposite. Antibacterial potential of the nanocomposite was also studied for two Gram-negative bacterial strains of Klebsiella pneumoniae and Enterobacter aerogenes where the maximum zone of inhibition observed was 32 mm and 33 mm at 40 mg/mL, respectively. The adsorption kinetic data of the PO₄^3- removal by MMT-CuONC was well represented by a pseudo-second-order model indicating chemisorptions of phosphate ions. The adsorption isotherm data fitted better to Langmuir isotherm illustrating monolayer sorption with the finite number of similar sites on the surface of the nanocomposite. Qm was 250 with monolayer adsorption capacity “b” = 0.0255 (L/mg). The adsorption thermodynamic studies suggest that the removal of phosphate by MMT-CuONC is endothermic and spontaneous in nature. The results revealed that MMT-CuONC acted as an efficacious adsorbent for the removal of phosphate from the waste water.

GRAPHICAL ABSTRACT

KEYWORDS:

• MMT-CuONC
• phosphate
• antibacterial activity
• klebsiella pneumoniae
• Enterobacter aerogenes

Acknowledgment

The author gratefully acknowledges U.G.C; New Delhi for the financial support to carry out this work. The corresponding author is thankful to UGC, New Delhi for the financial assistance in the form of DS Kothari Fellowship (Award No. CH/17-18/0041). The author thanks Materials Research Centre, Malaviya National Institute of Technology, Jaipur for FTIR; University Sophisticated Instrumentation Center and Baba Sahib Bhimrao Ambedkar University, Lucknow for SEM-EDX.

Statement of novelty

The montmorillonite-based copper oxide nanocomposites showed sufficient potential to be used for combined applications of water remediation. It showed a maximum of 89.2% removal of phosphate from the solution and an excellent zone of inhibition against gram-negative bacteria which was even larger than the control antibiotic zone of inhibition.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

The work was supported by the University Grants Commission [CH/17-18/0041]