Oil industry waste based non-magnetic and magnetic hydrochar to sequester potentially toxic post-transition metal ions from water

Moonis Ali Khan; Ayoub Abdullah Alqadami; Saikh Mohammad Wabaidur; Masoom Raza Siddiqui; Byong-Hun Jeon; Shareefa Ahmed Alshareef; Zeid A Alothman; Abdelrazig Elfaki Hamedelniel

doi:10.1016/j.jhazmat.2020.123247

Oil industry waste based non-magnetic and magnetic hydrochar to sequester potentially toxic post-transition metal ions from water

J Hazard Mater. 2020 Dec 5:400:123247. doi: 10.1016/j.jhazmat.2020.123247. Epub 2020 Jun 19.

Authors

Moonis Ali Khan¹, Ayoub Abdullah Alqadami², Saikh Mohammad Wabaidur², Masoom Raza Siddiqui², Byong-Hun Jeon³, Shareefa Ahmed Alshareef², Zeid A Alothman², Abdelrazig Elfaki Hamedelniel²

Affiliations

¹ Chemistry Department, College of Science, King Saud University, Riyadh 11451, Saudi Arabia. Electronic address: mokhan@ksu.edu.sa.
² Chemistry Department, College of Science, King Saud University, Riyadh 11451, Saudi Arabia.
³ Department of Earth Resources and Environmental Engineering, Hanyang University, 222, Wangsimni-ro, Seongdong-gu, Seoul, 04763, Republic of Korea.

PMID: 32947690
DOI: 10.1016/j.jhazmat.2020.123247

Abstract

Solid waste conversion to value-added products is a stepping stone towards sustainable environment. Herein, sesame oil cake (SOC), an oil industry waste was utilized as a precursor to develop hydrochar (HC) samples by varying reaction temperature (150-250 °C) and time span (2-8 h), chemically treated with 10% H₂O₂ to optimize a sample with maximum yield and Pb(II) adsorption. Highest yield (29.2 %) and Pb(II) (24.57 mg/g at C_o: 15 mg/L) adsorption was observed on SOCHC@200 °C/6 h, magnetized (mSOCHC@200 °C/6 h) for comparative study. XRD displayed highly crystalline SOCHC@200 °C/6 h and amorphous mSOCHC@200 °C/6 h, both having a characteristic cellulose peak at 14.9°. mSOCHC@200 °C/6 h displayed superparamagnetic behavior with 11.2 emu/g saturation magnetization. IR spectra confirmed the development of samples rich in oxygen containing functionalities; an additional peak for iron oxides appeared at 586 cm^-1 in mSOCHC@200°C/6 h spectrum. Four major peaks at 531.9, 399.9, 348.2 and 284.7 eV, assigned to O 1s, N 1s, Ca 2p and C 1s, respectively were observed during XPS analyses. An additional peak at 710.3 eV, ascribed to Fe 2p was observed in mSOCHC@200C/6 h XPS spectrum, while a peak at 143.2 eV for Pb 4f appeared in spectra of both Pb(II) saturated samples. pH dependent (maximum at ∼6.7), exothermic Pb(II) adsorption was found. About 50-70% (at C_o: 25 mg/L) adsorption on both SOCHC@200 °C/6 h and mSOCHC@200 °C/6 h was accomplished in a minute, attaining equilibrium in 180 and 240 min, respectively. Error functions and superimposed q_{e, exp}. and q_{e, cal.} values supported Langmuir isotherm model applicability, with respective q_m values of 304.9 and 361.7 mg/g at 25 °C for SOCHC@200 °C/6 h and mSOCHC@200 °C/6 h. Kinetic data was fitted to PSO model. Highest (between 92.2 and 88.9 %) amount of Pb(II) from SOCHC@200 °C/6 h and mSOCHC@200 °C/6 h was eluted by 0.01 M HCl.

Keywords: Adsorption; Hydrothermal carbonization; Lead; Sesame oil cake; Water treatment.

Publication types

Research Support, Non-U.S. Gov't