Evaluation of industrial based adsorbents for simultaneous removal of arsenic and fluoride from drinking water Sadia Bibi a , Abida Farooqi a, * , Khadim Hussain b , Naghma Haider b a Environmental Hydro Geochemistry Laboratory, Department of Environmental Sciences, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, Pakistan b Geoscience Advanced Research Laboratories, Chak Shahzd, Islamabad, Pakistan article info Article history: Received 28 January 2014 Received in revised form 5 September 2014 Accepted 8 September 2014 Available online 28 September 2014 Keywords: Arsenic Fluoride Removal % Separation factor Langmuir isotherm Freundlich isotherm abstract Evaluating the ability of industrial based adsorbents to remove arsenic and fluoride from drinking water has global significance due to their easy and widespread availability. Present study aimed to assess selected industrial waste materials for simultaneous removal of arsenic and fluoride from drinking water in order to find cost effective adsorbent. Commercially available Hydrated Cement, Marble Powder (waste) and Brick Powder (waste) were used. Adsorbents were characterized by using X-Ray Dif- fractrometry techniques. The surface morphology of adsorbents was studied by Scanning Electron Mi- croscopy (SEM). Batch adsorption tests were employed to evaluate the percent removal and adsorption capacity of adsorbents, under optimum conditions of adsorption time, dose, pH and adsorbate concen- tration. Removal percentage of studied adsorbents followed the decreasing trend: Hydrated Cement > Bricks Powder > Marble Powder. Hydrated Cement showed highest percentage removal, 97% and 80% for arsenic and fluoride respectively and was selected as the best media at neutral pH compared to other four adsorbents substantiating its potential for the drinking water treatment process. The applicability of the adsorbents for As was assessed under natural conditions with As contaminated groundwater samples collected from Tehsil Mailsi. In order to determine maximum adsorption capacity of adsorbents and to understand the nature of reaction on their surfaces, Langmuir and Freundlich isotherm were calculated. This study revealed that this new adsorbent (Hydrate Cement) is indigenous, easily available and could be easily applied in order to diminish the arsenic and fluoride pollution from drinking water. © 2014 Elsevier Ltd. All rights reserved. 1. Introduction Recognized as highly toxic elements, arsenic and fluoride are both contributors to the global water crisis, with significant health problems resulting from drinking water. This situation has become more serious due to increasing groundwater consumption in many countries like Pakistan, Bangladesh, India, and Nepal in the Indo region due to resource pressures from growing populations as well as surface water contamination (Farooqi et al., 2007; Kanel et al., 2006; Muhammad et al., 2010; Smedley and Kinniburgh, 2002). Arsenic is of serious concern because of its marked negative impacts to human health that range from acute lethality to chronic and carcinogenic effects (Abernathy et al., 2003). Most environ- mental arsenic problems are the result of mobilization under natural conditions. However, mining activities, combustion of fossil fuels, use of arsenic pesticides, herbicides, crop desiccants, waste- water discharge from mining/industry and use of arsenic additives to livestock feed create additional impacts. Arsenic and its de- rivatives are being used for many years and still they are in use like in electronics, material sciences and in medicines (Mudhoo et al., 2011; Baidya et al., 2006; Ghosh et al., 2007; Mukherjee et al., 2003; Tseng, 2004). Arsenic is present in a variety of forms, organic and inorganic, and oxidation states, in which the valances depend on the pH and redox conditions (Abernathy et al., 2003; Saha et al., 1999). At ambient water pH 6 to 9, the predominant forms are: As-III (Arsenite) present as Arsenious Acid H 3 AsO 3 and AseV (Arsenate) present as anions H 2 AsO 4  and HAsO 4 2 (Mudhoo et al., 2011; Kumaresan and Riyazuddin, 2001). At low pH, in the presence of sulfide, HAsS 2 can be formed; arsine, arsine derivatives, and arsenic metal can occur under extremely reducing conditions (Mudhoo et al., 2011; Kumaresan and Riyazuddin, 2001). All inor- ganic compounds of arsenic are toxic, in particular present in * Corresponding author. Tel.: þ92 5190644139. E-mail address: abida.farrukh@gmail.com (A. Farooqi). Contents lists available at ScienceDirect Journal of Cleaner Production journal homepage: www.elsevier.com/locate/jclepro http://dx.doi.org/10.1016/j.jclepro.2014.09.030 0959-6526/© 2014 Elsevier Ltd. All rights reserved. Journal of Cleaner Production 87 (2015) 882e896