Cost-effectiveness analysis of TOC removal from slaughterhouse wastewater using combined anaerobiceaerobic and UV/H 2 O 2 processes Ciro Fernando Bustillo-Lecompte a , Mehrab Mehrvar b, * , Edgar Quiñones-Bolaños c a Graduate Program in Environmental Applied Science and Management, Ryerson University, 350 Victoria Street, Toronto, ON M5B 2K3, Canada b Department of Chemical Engineering, Ryerson University, 350 Victoria Street, Toronto, ON M5B 2K3, Canada c Facultad de Ingeniería, Universidad de Cartagena, Centro e Cr6 No 36-100, Cartagena de Indias, Colombia article info Article history: Received 23 May 2013 Received in revised form 10 December 2013 Accepted 31 December 2013 Available online 30 January 2014 Keywords: Cost-effectiveness analysis (CEA) Slaughterhouse wastewater (SWW) Activated sludge (AS) Advanced oxidation processes (AOPs) UV/H 2 O 2 TOC abstract The objective of this study is to evaluate the operating costs of treating slaughterhouse wastewater (SWW) using combined biological and advanced oxidation processes (AOPs). This study compares the performance and the treatment capability of an anaerobic baffled reactor (ABR), an aerated completely mixed activated sludge reactor (AS), and a UV/H 2 O 2 process, as well as their combination for the removal of the total organic carbon (TOC). Overall efficiencies are found to be up to 75.22, 89.47, 94.53, 96.10, 96.36, and 99.98% for the UV/H 2 O 2 , ABR, AS, combined ASeABR, combined ABReAS, and combined ABR eASeUV/H 2 O 2 processes, respectively. Due to the consumption of electrical energy and reagents, oper- ating costs are calculated at optimal conditions of each process. A cost-effectiveness analysis (CEA) is performed at optimal conditions for the SWW treatment by optimizing the total electricity cost, H 2 O 2 consumption, and hydraulic retention time (HRT). The combined ABReASeUV/H 2 O 2 processes have an optimal TOC removal of 92.46% at an HRTof 41 h, a cost of $1.25/kg of TOC removed, and $11.60/m 3 of treated SWW. This process reaches a maximum TOC removal of 99% in 76.5 h with an estimated cost of $2.19/kg TOC removal and $21.65/m 3 treated SWW, equivalent to $6.79/m 3 day. Ó 2014 Elsevier Ltd. All rights reserved. 1. Introduction Slaughterhouse wastewater (SWW) is considered detrimental worldwide due to its composition, characterized mostly by a complex mixture of fats, proteins, and fibers (Johns, 1995; Muñoz, 2005). Wastewaters from slaughterhouses and meat processing plants (MPPs) have been considered as an industrial wastewater in the category of agricultural and food industries (Seif and Moursy, 2001). It has been classified as one of the most harmful wastewa- ters to the environment by the United States Environmental Pro- tection Agency (US EPA, 2004). The effluent discharge from slaughterhouses causes deoxygenation of rivers (Quinn and McFarlane, 1989) and contamination of groundwater (Masse and Masse, 2000a). The organic matter concentration in SWW is usually high and the residues are moderately solubilized, leading to a highly polluting effect (Ruiz et al., 1997). They usually contain high levels of organics, pathogenic and non-pathogenic viruses and bacteria, and detergents and disinfectants used for cleaning activities (Debik and Coskun, 2009). High concentrations of biochemical oxygen demand (BOD), chemical oxygen demand (COD), total organic carbon (TOC), total nitrogen (TN), and total suspended solids (TSS) in SWW containing flesh and blood have been reported to be 4635, 15,900, 1200, 841, and 2800 mg/L or more, respectively (Tritt and Schuchardt, 1992; Masse and Masse, 2000b). Several studies have described the common characteristics of SWW (Gariepy et al., 1989; Seif and Moursy, 2001; Cao and Mehrvar, 2011; Wu and Mittal, 2011; Barrera et al., 2012; Bustillo-Lecompte et al., 2013). These characteristics are summarized in Table 1 , in which their common ranges and averages of COD, TOC, BOD, TSS, TN, and pH for SWW are presented. Commonly, research on wastewater treatment includes the study of different contaminants, the effects of operating variables, and the efficiency of the processes. Nevertheless, there are limited studies on the economic information and analysis, reaction mechanisms, and kinetic modeling that may help to estimate the costs of different technologies for scale-up and industrial applications (Durán et al., 2012; Benedetti et al., 2013; Ghafoori et al., 2012, 2013, 2014). * Corresponding author. Tel.: þ1 416 979 5000x6555; fax: þ1 416 979 5083. E-mail address: mmehrvar@ryerson.ca (M. Mehrvar). Contents lists available at ScienceDirect Journal of Environmental Management journal homepage: www.elsevier.com/locate/jenvman 0301-4797/$ e see front matter Ó 2014 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.jenvman.2013.12.035 Journal of Environmental Management 134 (2014) 145e152