Journal of Emerging Trends in Engineering and Applied Sciences (JETEAS) 5(1):62-69 (ISSN: 2141-7016) 62 Diffusivity and Kinetics Model for Biodegradation of PAHs in a Saturated Porous Matrix Azeez Taofik Oladimeji 1 , Arinkoola Akeem.Olatunde 2 ., Salam Kazeem. Kolapo 3 , and Nwakaudu Madueke. Stanley 4 1 Biomedical Technology Department, Federal University of Technology, P. M. B. 1526, Owerri, Imo State, Nigeria. 2,3 Chemical Engineering Department, Ladoke Akintola University of Technology, P. M. B. 4000, Ogbomoso, Oyo State, Nigeria. 4 Chemical Engineering Department, Federal University of Technology, P. M. B. 1526, Owerri, Imo State, Nigeria. Corresponding Author: Azeez Taofik Oladimeji _________________________________________________________________________________________ Abstract The commercial implementation of biodegradation of polycyclic aromatic hydrocarbons (PAHs) as a bioremediation technique against physical process was due to lack of its effective and efficient diffusivity model with reaction parameters in a saturated porous matrix. The development and simulation of diffusivity model which involve reaction kinetics was aimed to provide quantitative insight on biodegradation of PAHs. The developed model obtained from the principle of conservation of matter, concepts of Fick’s law of diffusion, Malthus equation and Monod kinetics expression under isothermal condition was simulated with experimental data. The result showed that Corynebacterium sp and Pseudomonas putida were effective and PAHs exhibits pseudo first order reaction. Though, the effective diffusivity of PAHs decreases as degradation of PAHs proceeds with increased microbial mass concentration at increased penetration depth. The developed diffusivity model has been shown to be effective and not only providing quantitative insight into biodegradation of the PAHs but serves as an alternative option in the selection of microbes capable of facilitating the restoration of PAHs contaminated sites. __________________________________________________________________________________________ Keywords: kinetics, conservation laws, microbial degradation, effective diffusivity INTRODUCTION The human survival and quality of life have led to enormous anthropogenic activities on the environment (soil and groundwater) due to the proliferation of contaminants through industrial chemical effluent, emissions from combustion processes, spillage of petroleum products and agrochemical discharged to the environment (Mihoko et al, 2003; Kanaly & Harayama, 2000). These environmental concerns become a menace to posterity if left unchecked. The industrial effluent discharged into the environment increased the level of contaminants in soil, sediments and aquatic systems causing environmental degradation and health problems through diffusion (Azeez et al, 2012). The extent of contamination depends on the nature of the contaminant and hydrogeology of the area. Polycyclic aromatic hydrocarbons (PAHs) are among the most concerned organic contaminants which persistent and toxic in the environment (Azeez et al, 2012; Azeez, 2012). The sources of PAHs include emissions from combustion processes, spillage of petroleum products, vehicle emissions, industrial processes, refuse and open burning, and forest-fire ((Mihoko et al, 2003; Kanaly & Harayama, 2000; Azeez et al, 2012; Azeez, 2012; Kumar et al, 2006; Hsiao-Hsuan et al, 2001). Anthracene and pyrene are examples of PAHs that harmful at high concentration in the contaminated sediments, surface soils and waste slurries due to its hydrophobic nature (Corgie et al, 2004; Masih & Taneja , 2006; Li et al, 2008). PAHs have been recently included in the Substances of Very High Concern list (SVHC) by the European Chemicals Agency (ECHA) due to persistent, bioaccumulative and toxic nature on discharged to environment (Iglesias-Groth et al, 2010; Mrozik et al, 2003; Shor et al, 2004). However, there is a need for the provision and protection of the environment, soil and groundwater from the adverse effects of PAHs (Masih & Taneja , 2006; Samanta et al, 2002). This is one of the reasons for remediation of PAHs in the environments. Clean-up techniques involving physical and chemical intervention are quite widespread which include disposal in a landfill, incineration of the wastes and direct injection of chemical oxidants into contaminated soil, sediment and groundwater, thereby altering nature of environments (Cameotra, & Makkar, 2010; Jacques Journal of Emerging Trends in Engineering and Applied Sciences (JETEAS) 5(1): 62-69 © Scholarlink Research Institute Journals, 2014 (ISSN: 2141-7016) jeteas.scholarlinkresearch.org, jeteas.scholarlinkresearch.com