Journal of Hazardous Materials 183 (2010) 381–388 Contents lists available at ScienceDirect Journal of Hazardous Materials journal homepage: www.elsevier.com/locate/jhazmat The effect of carbon type on arsenic and trichloroethylene removal capabilities of iron (hydr)oxide nanoparticle-impregnated granulated activated carbons Anne Marie Cooper a,1 , Kiril D. Hristovski b,∗ , Teresia Möller c,2 , Paul Westerhoff d,3 , Paul Sylvester c,2 a Environmental Technology, College of Technology and Innovation. Arizona State University – Polytechnic Campus, 6075 South Williams Campus Loop West, Mesa, AZ 85212, United States b Environmental Technology, College of Technology and Innovation, Arizona State University – Polytechnic Campus, 6073 South Backus Mall, Mesa, AZ 85212, United States c SolmeteX – Division of Layne Christiansen, 50 Bearfoot Road, Northborough, MA 01532, United States d School of Sustainable Engineering and the Built Environment, Arizona State University, Box 5306, Tempe, AZ 85287-5306, United States article info Article history: Received 19 April 2010 Received in revised form 9 July 2010 Accepted 9 July 2010 Available online 16 July 2010 Keywords: Arsenic Nanoparticle Iron (hydr)oxide GAC Adsorption Trichloroethylene Water treatment abstract This study investigates the impact of the type of virgin granular activated carbon (GAC) media used to synthesize iron (hydr)oxide nanoparticle-impregnated granular activated carbon (Fe-GAC) on its proper- ties and its ability to remove arsenate and organic trichloroethylene (TCE) from water. Two Fe-GAC media were synthesized via a permanganate/ferrous ion synthesis method using bituminous and lignite-based virgin GAC. Data obtained from an array of characterization techniques (pore size distribution, surface charge, etc.) in correlation with batch equilibrium tests, and continuous flow modeling suggested that GAC type and pore size distribution control the iron (nanoparticle) contents, Fe-GAC synthesis mecha- nisms, and contaminant removal performances. Pore surface diffusion model calculations predicted that lignite Fe-GAC could remove ∼6.3 L g -1 dry media and ∼4Lg -1 dry media of water contaminated with 30 gL -1 TCE and arsenic, respectively. In contrast, the bituminous Fe-GAC could remove only ∼0.2 L/g dry media for TCE and ∼2.8 L/g dry media for As of the same contaminated water. The results show that arsenic removal capability is increased while TCE removal is decreased as a result of Fe nanoparticle impregnation. This tradeoff is related to several factors, of which changes in surface properties and pore size distributions appeared to be the most dominant. © 2010 Elsevier B.V. All rights reserved. 1. Introduction The availability of clean drinking water is a problem faced by developed as well as developing nations, as population growth has created a worldwide demand for new water sources [1]. Unfor- tunately, many potential water sources contain high levels of contaminants from natural and anthropogenic origins that are haz- ardous to human health. Arsenic is a naturally occurring water contaminant that can also occur as a result of anthropogenic activi- ties [2]. Arsenic levels in fresh waters typically are below 10 gL -1 , but can reach concentrations in excess of several hundred gL -1 [3]. Because of the known carcinogenicity and toxicity of arsenic, the United States Environmental Protection Agency (USEPA) has established a maximum contaminant level (MCL) of 10 gL -1 in ∗ Corresponding author. Tel.: +1 480 727 1291; fax: +1 480 727 1236. E-mail addresses: Anne.M.Cooper@asu.edu (A.M. Cooper), Kiril.Hristovski@asu.edu (K.D. Hristovski), tmoller@solmetex.com (T. Möller), p.westerhoff@asu.edu (P. Westerhoff), psylvester@solmetex.com (P. Sylvester). 1 Tel.: + 1 480 727 1132. 2 Tel.: +1 508 393-5115; fax: +1 508 393 1795. 3 Tel.: +1480 965-2885; fax: +1 480 965 0557. drinking water [4,5]. Recent arsenic risk assessments suggest that this MCL may be further lowered to 0.1 gL -1 [5]. This new reg- ulatory pressure may require revisiting old and developing new treatment approaches for arsenic removal. Adsorption of arsenic by metal (hydr)oxides has been shown to be effective in removing arsenic below the existing MCL [6–11]. This technology is espe- cially suitable for small and portable point-of-use systems such as those found in small communities where energy-demanding con- ventional water treatment technologies are unavailable. Water sources may also contain other contaminants that have different chemistries than arsenic. Organic chemicals, for example, can often be found in groundwaters, especially in areas affected by heavy industrial activity. Trichloroethylene (TCE) is a typical organic contaminant found in drinking water supplies because of metal degreasing activities [12]. The USEPA has established a drink- ing water MCL for TCE of 5 gL -1 , which is even lower than that for arsenic [13]. The presence of multiple inorganic and organic co-contaminants in water sources, such as arsenic and TCE, can further complicate water treatment. However, TCE can be consid- ered a model organic contaminant in this context because it does not interact with arsenate or compete for its adsorption sites as a result of its different chemistry. 0304-3894/$ – see front matter © 2010 Elsevier B.V. All rights reserved. doi:10.1016/j.jhazmat.2010.07.036