Elimination of heavy metal Ni 2+ from wastewater using Moroccan oil shale as bio sorbent Sanaa Saoiabi a,⇑ , Souhayla Latifi a,b , Asmae Gouza a , Larbi El Hammari a , Omar Boukra a , Ahmed Saoiabi a a Laboratory of Applied Chemistry of Materials, Department of Chemistry, Faculty of Sciences, Mohammed V University, Rabat, Morocco b Laboratory REMTEX, ESITH (Higher School of Textile and Clothing Industries), Casablanca, Morocco article info Article history: Available online 7 January 2022 Keywords: Oil shale Wastewater Nickel Adsorption Pseudo-second order Langmuir abstract The process of adsorption of nickel ions by natural oil shales from deposits in the Tangier region in north- ern Morocco has been studied experimentally. Thermal degradation and specific surface area of OST 100 were studied by thermogravimetric and BET analysis, respectively, as well as characterization of OST 100 by FTIR, and DRX showed that the shales consisted of SiO 2 which is very interesting for adsorption. The results of the adsorption study obtained show Ni 2+ was adsorbed by 20 mg/g from wastewater and the elimination process is highly dependent on Physico-chemical parameters (pH, contact time, initial con- centration of the adsorbate, and the mass of the adsorbent). The mechanism of nickel ion adsorption was best described by the pseudo-second-order kinetic model and obeyed linear models of the Langmuir isotherms, showing adsorption is done in the area of OST 100, OST 500, and OST 950. Copyright Ó 2022 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the 3rd International Con- gress on Materials & Structural Stability. 1. Introduction The earth’s crust contains naturally heavy metals, but urbaniza- tion, industrial activities, and research activities have caused dras- tic changes in their geochemical cycles. Certain metals such as iron, zinc, cobalt, and manganese are necessary for the human body [1]. If the concentration of these metals is very high, they can become very toxic. This increase in concentration can disturb the environ- ment causing serious risks to the ecological system [2]. However, heavy metals are not biodegradable and can be accumulated in animals and humans after the consumption of contaminated food and water [3]. Heavy metals such as Ni, Cu, Zn, Hg, and as have drawn the attention of researchers because of their high toxicities even at very low concentrations, as well as their difficulty of elimination by natural degradation [4]. Nickel (Ni) is one of the toxic heavy metals that contributes to environmental degradation. Vehicle emissions, fossil fuel combustion, municipal and industrial waste, electric batteries, and the metallurgical and electroplating indus- tries are the main sources of Ni 2+ in soil, water, and air [5]. Expo- sure to excessive levels of these elements in the environment creates environmental pollution problems. For this, it is necessary to develop methodologies for the remediation of sites contami- nated by these metals. Conventional technologies have been used in the removal of heavy metal ions from aqueous solutions such as chemical precip- itation [6], ion exchange [7], reverse osmosis [8], electrochemical treatment [9], membrane filtration [10], coagulation-flocculation [11], flotation [12] and adsorption [13]. The latter (adsorption) is the most widely used method for the removal or reduction of heavy metals from contaminated liquids. Adsorption consists of using adsorbents of organic origin such as activated carbon [14,15], bio adsorbents [16], and mineral origin like silicates [17], natural zeolites [18], and natural clays [19]. Even if these adsorbents are very effective, but their loss during regener- ation and their high cost limit their application [20]. For this rea- son, several researchers have focused their studies on developing alternative and more economical adsorbents. In this context, Saoiabi et al incorporated the apatites by adipic acid, citric acid, and nitrilotris (methylene) triphosphonic acid, for the removal of Pb 2+ in acidic solutions [21], also that petra et al have worked with nanoscale aluminosilicates of the smectite groups for the adsorption of Cu 2+ and Ni 2+ [22] and shawabkeh et al used the ash from the Jordanian oil shale as an adsorbent to remove copper and zinc found in an aqueous solution [23]. https://doi.org/10.1016/j.matpr.2021.12.457 2214-7853/Copyright Ó 2022 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the 3rd International Congress on Materials & Structural Stability. ⇑ Corresponding author. E-mail address: sanaa.saoiabi@yahoo.com (S. Saoiabi). Materials Today: Proceedings 58 (2022) 987–993 Contents lists available at ScienceDirect Materials Today: Proceedings journal homepage: www.elsevier.com/locate/matpr