Encapsulated green magnetic nanoparticles for the removal of toxic Pb2+ and Cd2+ from water: Development, characterization and application

Imran Ali; Changsheng Peng; Dichu Lin; Devendra P Saroj; Iffat Naz; Zahid M Khan; Muhammad Sultan; Mohsin Ali

doi:10.1016/j.jenvman.2018.12.112

Encapsulated green magnetic nanoparticles for the removal of toxic Pb²⁺ and Cd²⁺ from water: Development, characterization and application

J Environ Manage. 2019 Mar 15:234:273-289. doi: 10.1016/j.jenvman.2018.12.112. Epub 2019 Jan 8.

Authors

Imran Ali¹, Changsheng Peng², Dichu Lin³, Devendra P Saroj⁴, Iffat Naz⁵, Zahid M Khan⁶, Muhammad Sultan⁷, Mohsin Ali⁸

Affiliations

¹ Department of Environmental Engineering, College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100, China; The Key Lab of Marine Environmental Science and Ecology, Ministry of Education, Ocean University of China, Qingdao, 266100, China. Electronic address: engrimran56@gmail.com.
² Department of Environmental Engineering, College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100, China; The Key Lab of Marine Environmental Science and Ecology, Ministry of Education, Ocean University of China, Qingdao, 266100, China; School of Environment and Chemical Engineering, Zhaoqing University, Zhaoqing, 526061, China. Electronic address: cspeng@ouc.edu.cn.
³ Department of Environmental Engineering, College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100, China; The Key Lab of Marine Environmental Science and Ecology, Ministry of Education, Ocean University of China, Qingdao, 266100, China.
⁴ Department of Civil and Environmental Engineering, Faculty of Engineering and Physical Sciences, University of Surrey, Surrey, GU2 7XH, United Kingdom.
⁵ Department of Civil and Environmental Engineering, Faculty of Engineering and Physical Sciences, University of Surrey, Surrey, GU2 7XH, United Kingdom; Department of Biology, Deanship of Educational Services, Qassim University, Buraidah, 51452, Saudi Arabia.
⁶ Department of Agricultural Engineering, Bahauddin Zakariya University, Bosan Road, Multan, 60800, Pakistan.
⁷ Department of Agricultural Engineering, Bahauddin Zakariya University, Bosan Road, Multan, 60800, Pakistan. Electronic address: muhammadsultan@bzu.edu.pk.
⁸ Department of Environmental Engineering, Middle East Technical University, Ankara, 0600, Turkey.

PMID: 30634120
DOI: 10.1016/j.jenvman.2018.12.112

Abstract

Current research is based on an innovative approach of the fabrication of encapsulated sustainable, green, phytogenic magnetic nanoparticles (PMNPs), to inhibit the generation of secondary pollutants (Iron/Fe^o) during water treatment applications. These novel bio-magnetic membrane capsules (BMMCs) were prepared using two-step titration gel crosslink method, with polyvinyl alcohol and sodium alginate matrix as the model encapsulating materials to eliminate potentially toxic metals (Pb²⁺ and Cd²⁺) from water. The development of BMMCs was characterized by FTIR, XRD, XPS, SEM, VSM, TGA and EDX techniques. The effects of various operating parameters, adsorbent dose, contact time, solution pH, temperature, initial concentration of metals cations and co-existing ions were studied. The hysteresis loops have illustrated an excellent super-paramagnetic nature, demonstrating the smooth encapsulation of PMNPs without losing their magnetic properties. The maximum monolayer adsorptive capacities estimated at pH 6.5 by the Langmuir isotherm model were 548 and 610.67 mg/g for Pb²⁺ and Cd²⁺, respectively. The novel BMMCs did not only control oxidation of PMNPs but also sustained the adsorptive removal over a wide range of pH (3-8), and the electrostatic interaction and ion-exchange were the core adsorption mechanisms. The BMMCs could easily be regenerated using 25% HNO₃ as an eluent for successful usage in seven repeated cycles. Therefore, the BMMCs as a material can be used as an excellent sorbent or composite material to remove toxic metals Pb²⁺ and Cd²⁺, showing strong potential for improving water and wastewater treatment technologies.

Keywords: Adsorptive performance; Cd(2+); Magnetic nanoparticles; Membrane capsules; Pb(2+); Titration gel.

MeSH terms

Adsorption
Cadmium
Hydrogen-Ion Concentration
Kinetics
Lead
Magnetite Nanoparticles*
Water
Water Pollutants, Chemical*
Water Purification*

Substances

Magnetite Nanoparticles
Water Pollutants, Chemical
Cadmium
Water
Lead