Contents lists available at ScienceDirect Journal of Environmental Management journal homepage: www.elsevier.com/locate/jenvman Research article Efficient mercury removal from wastewater by pistachio wood wastes- derived activated carbon prepared by chemical activation using a novel activating agent Seyed-Ali Sajjadi a , Alireza Mohammadzadeh b , Hai Nguyen Tran c,* , Ioannis Anastopoulos d , Guilherme L. Dotto e , Zorica R. Lopičić f , Selvaraju Sivamani g , Abolfazl Rahmani-Sani h , Andrei Ivanets i , Ahmad Hosseini-Bandegharaei a,j,** a Environment Health Engineering Department & Social Determinants of Health Research Centre, Gonabad University of Medical Sciences, Gonabad, Iran b Department of Microbiology, Faculty of Medicine, Gonabad University of Medical Sciences, Gonabad, Iran c Institute of Research and Development, Duy Tan University, Da Nang, 550000, Vietnam d Department of Agrobiotechnology, Agricultural Research Institute, P.O. Box 22016, 1516, Nicosia, Cyprus e Environmental Processes Laboratory, Chemical Engineering Department, Federal University of Santa Maria–UFSM, 1000, Roraima Avenue, 97105-900, Santa Maria, Brazil f Institute for Technology of Nuclear and Other Mineral Raw Materials, 86 Franchetd'Esperey St., 11000, Belgrade, Serbia g Chemical and Petrochemical Engineering Section, Engineering Department, Salalah College of Technology, Oman h Department of Environmental Health Engineering, Faculty of Health, Sabzevar University of Medical Sciences, PO Box 319, Sabzevar, Iran i Institute of General and Inorganic Chemistry of National Academy of Sciences of Belarus, St. Surganova 9/1, 220072, Minsk, Belarus j Department of Engineering, Kashmar Branch, Islamic Azad University, PO Box 161, Kashmar, Iran ARTICLE INFO Keywords: Activated carbon Ammonium nitrate Chemical activation Adsorption Mercury Agricultural waste ABSTRACT Ammonium nitrate (NH 4 NO 3 ) with explosive characteristics at high temperatures was used as a novel activating reagent to prepare a surface-engineered activated carbon derived from pistachio wood wastes (PWAC). PWAC was characterized and compared with commercial activated carbon (CAC) by textural and morphological properties, surface chemistry, crystal structure, and surface elemental composition. The results indicated that the optimal conditions of PWAC preparation to obtain the highest mercury adsorption capacity were pyrolysis temperature (800 °C), pyrolysis time (2 h), and impregnation ratio (5%). PWAC was of highly regular-shaped and well-developed pores and possessed a large surface area (1448 m 2 /g) and high total pore volume (0.901 cm 3 /g). The batch experiments indicated that the adsorption process of Hg(II) was strongly dependent on the solution pH and reached fast equilibrium at approximately 30 min. PWAC (202 mg/g) exhibited a significantly higher maximum adsorption capacity than commercial activated carbon (66.5 mg/g). Adsorbent-adsorbate dispersion interaction plays a major role in the adsorption mechanism, compared to the minor role played by pore filling and reduction mechanism. Overall, ammonium nitrate can be considered a newer activating reagent to prepare promising and low-cost PWAC for effectively Hg(II) removal from water media. 1. Introduction Mercury present in water environment is enormously concerning for public health because of its high toxicity to human health and aquatic organisms, such as neurological damage, paralysis, blindness, chro- mosomes breakage (Sigel and Sigel, 1997; Hosseini-Bandegharaei et al., 2011). World Health Organization has announced that mercury is one of the most ten toxic chemicals of major public health concern. The incorrect discharge of industrial effluents accounts for the environ- mental concerns over this toxic compound (Hadi et al., 2015). In this sense, the removal of Hg from aqueous media is a global concern. A cost–effective and simple method for removing mercury and other heavy metals from water and wastewater is expected by promising adsorbents with their highly effective adsorption capacity (Song et al., 2017; Dotto et al., 2017). Activated carbon (AC) has been acknowledged as a potential https://doi.org/10.1016/j.jenvman.2018.06.077 Received 31 March 2018; Received in revised form 29 May 2018; Accepted 25 June 2018 * Corresponding author. Institute of Research and Development, Duy Tan University, Da Nang 550000, Vietnam. ** Corresponding author. Department of Engineering, Kashmar Branch, Islamic Azad University, PO Box 161, Kashmar, Iran. E-mail addresses: trannguyenhai@duytan.edu.vn, trannguyenhai2512@gmail.com (H.N. Tran), ahoseinib@yahoo.com (A. Hosseini-Bandegharaei). Journal of Environmental Management 223 (2018) 1001–1009 0301-4797/ © 2018 Elsevier Ltd. All rights reserved. T