In this work, palm-shell waste powder activated carbon (PPAC) coated by magnesium
silicate (PPAC-MS) were successfully synthesized by the impregnation of magnesium
silicate (MgSiO3) using economical material (silicon dioxide powder) via mild
hydrothermal approach under one-pot synthesis for the first time. Surprisingly, PPACMS
exhibited a homogeneous thin plate mesh-like structure, as well as meso- and
macro-pores with a high surface area of 772.1 m2 g-1. Different impregnation ratios of
MgSiO3 onto PPAC were tested from 0% to 300%. High amounts of MgSiO3 led to
high Cu (II) adsorption capacity. A ratio of 1:1, designated as PPAC-MS 100, was
considered optimum because of its chemical stability in solution. The maximum
adsorption capacity of PPAC-MS 100 for Cu (II) obtained by isotherm experiments was
369 mg g-1. Kinetic adsorption data fitted to pseudo-second-order revealed
chemisorption. Increasing ionic strength reduced Cu (II) adsorption capacity because of
the competition effect between Na+ and Cu2+. Three times of regeneration studies were
also conducted for Cu (II) removal. In addition, PPAC-MS 100 showed sufficient
adsorption capacity on removal Zn (II), Al (III), Fe (II), Mn (II), and As (V) with the
adsorption capacity of 373 mg g-1, 244 mg g-1, 234 mg g-1, 562 mg g-1, 191 mg g-1,
respectively. As an effective adsorbent, PPAC-MS 100 simultaneously removes
Bisphenol A (BPA) and Pb (II) in single and binary mode. Due to its specific
morphological characteristics, PPAC-MS 100 had adsorption capacities of Pb (II) as
high as 419.9 mg g-1 and 408.8 mg g-1 in single mode and binary mode based on
Freudliuch isotherm model while those for BPA by PPAC-MS were 168.4 mg g-1 and
254.7 mg g-1 for single mode and binary modes corresponding to Langmuir isotherm
model. Experiment results also indicated that the synergistic removal of BPA occurred
because the precipitation process of Pb (II) leads to the co-precipitation of BPA with Pb(OH)2 compound. PPAC-MS showed a good reusability for 5 regeneration cycles
using Mg (II) solution followed by thermal treatment. PPAC-MS is characterized by
Fourier Transformed Infrareds (FTIR), nitrogen adsorption/desorption analysis, X-Ray
powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and Field Emission
Scanning Electron Microscope (FESEM). Overall, PPAC-MS has a high potential in the
treatment process for wastewater containing both toxic heavy metals and emerging
pollutants due to its high sorption capacities and reusability, while remaining
economical through the reuse of palm-shell waste materials
