Rev Chem Eng 2014; 30(5): 431–451 Mohammed Evuti Abdullahi, Mohd Ariffin Abu Hassan*, Zainura Zainon Noor and Raja Kamarulzaman Raja Ibrahim Application of a packed column air stripper in the removal of volatile organic compounds from wastewater Abstract: Addressing environmental degradation and ensuring environmental sustainability are inextricably linked to all methods of reducing volatile organic com- pounds (VOCs) from the environment. A packed column air stripper is a typical example of such technologies for the removal of VOCs from polluted water. The present review is devoted to the applications of a packed column air strip- per and, in comparison with previous reviews, presents further elaborations and new information on topics such as modeling and simulation of the dynamic behavior of the air stripping process in a packed column air stripper. The paper observed that a knowledge gap still exists in the synthesis of this knowledge to formulate practically appli- cable mathematical relationships to describe the process generally. Therefore, further researches are still required in the area of air stripper performance optimization, par- ticularly in the development of a mathematical model and the optimization of an air stripper using a statisti- cal experimental design method. Such a determination is critical to the understanding of the interactive effect of process variables such as temperature, air-to-water (A/W) ratio, and height of packing on air stripper performance. Keywords: modeling; packed column air stripper; volatile organic compounds; wastewater. DOI 10.1515/revce-2014-0003 Received January 14, 2014; accepted June 5, 2014; previously pub- lished online August 5, 2014 1 Introduction There is an increasing public concern on the need to remove volatile organic compounds (VOCs) from ground- water and wastewater because certain VOCs are known to be hazardous to human health and the environment (Gold- stein and Galbally 2007). Some VOCs have been identified as odorous, ozone precursors, carcinogenic, and potential air toxicants (Inoue et al. 2011). About 189 hazardous air pollutants (HAPs) have been identified by U.S. Environ- mental Protection Agency (USEPA), out of which 97 are VOCs (USEPA 1990). There also exists mounting evidence that long-time exposure to low concentrations of certain organic chemicals can be an important factor in the devel- opment and manifestation of some chronic diseases. It is further believed that between 80% and 90% of cancer cases are of environmental origin; therefore, the contami- nants present in potable water supplies come under suspi- cion (Bedding et al. 1982). More also, certain VOCs are also known as greenhouse gases (Derwent 1995, Wuebbles and Hayhoe 2002, IPCC 2006, Lelieveld et al. 2009). Because these gases effectively absorb radiated energy from the Earth, the rise in their concentrations within the Earth’s atmosphere has been associated with the global warming phenomena (AEA Group 2007, Mohammed et al. 2012). In addition, the presence of VOCs in wastewater reduces the possibility of water reuse, such as in irrigation, thereby placing a higher demand on the limited existing primary water resources (Bedding et al. 1982). This increasing concern is also due to the increase in the numbers and quantities of VOCs in use, which have made the water resources used for portable supply to have become increasingly susceptible to contamina- tion by VOCs from various sources. Abdullahi and Chian (2011), in their study of VOCs in drinking water in pen- insular Malaysia, detected 54 different VOCs species in samples analyzed from 11 states, which were attributed to improper disposal practice. The result showed that the number of significant compounds detected increased with the extent of infrastructure growth in the state, with *Corresponding author: Mohd Ariffin Abu Hassan, Institute of Environmental and Water Resources Management, Universiti Teknologi Malaysia-Johor Bahru, Johor Bahru, Johor 81310, Malaysia, e-mail: mariffin@utm.my Mohammed Evuti Abdullahi: Faculty of Chemical Engineering, Department of Chemical Engineering, Universiti Teknologi Malaysia- Johor Bahru, Johor Bahru, Johor 81310, Malaysia Zainura Zainon Noor: Institute of Environmental and Water Resources Management, Universiti Teknologi Malaysia-Johor Bahru, Johor Bahru, Johor 81310, Malaysia Raja Kamarulzaman Raja Ibrahim: Advanced Photonic Science Institute, Faculty of Science, Physics Department, Universiti Teknologi Malaysia-Johor Bahru, Johor Bahru, Johor 81310, Malaysia Brought to you by | University of Pittsburgh Authenticated Download Date | 1/5/15 7:21 AM