Removal of some heavy metals and fungicides from aqueous solutions using nano-hydroxyapatite, nano-bentonite and nanocomposite

A batch adsorption experiments were carried out to study the role of nanoparticles and nanocomposite on removal of some heavy metals and fungicides from aqueous solution. Nano-Hydroxyapatite (n-HAP), Nano-Bentonite (n-Bo) and Bentonite-hydroxyapatite nanocomposite (B-HAP NC) evaluated for the removal of some heavy metals and fungicides. The nanoparticles and nanocomposite were characterized by TEM, SEM and AFM, X-ray powder diffraction (XRD) and BET surface area. The batch adsorption was done using nanoparticles with Pb2+ and Ni2+ as example of heavy metals with concentrations up to 25 mgL(-1). Also, the adsorption experiment was conducted using nano-particles (n-HAP, n-Bo and B-HAP NC) with fungicides Stop Feng and Eurozole with concentrations 20 to 200 mu g L-1. Langmuir and Freundlich isotherm equations were employed to study the adsorption. The adsorption kinetics were conducted metal ion (Pb2+ and Ni2+) with residence time. The results indicated the maximum adsorption capacity of Ni+2 was occurred on (n-HAP). While that maximum adsorption capacity of Pb2+ was occurred on (B-HAP NC). The rate of Ni+2 removal was found to be very rapid during the initial 60 min. The adsorption of Pb+2 by the n-HAP and (B-HAP NC) was a slow increase with time, it did not bring any remarkable effect. Also, the efficiency of adsorbent compounds used to remove the residue of fungicides Stop Feng and Eurozole shown the highest removal rates obtained with used nano-hydroxyapatite followed by bentonite-hydroxyapatitenanocomposite and nano-bentonite, respectively. The current results are very useful in the treatment of wastewater and the removal of heavy metals and fungicides, consequently making them suitable for agricultural purposes. (C) 2020 The Authors. Published by Elsevier B.V. on behalf of King Saud University.