## 1 Introduction  
Xenobiotic compounds are synthetic molecules which include halogenated hydrocarbon, polyaromatic hydrocarbons, polycyclic biphenyls, and lignin [1,2]. They are biologically active compounds that are widely used in several drug and pesticide industries [3,4]. Hence, xenobiotic compounds often appear in industrial wastewaters and aquatic ecosystems [5,6]. Xenobiotic compounds can be considered stable, in the thermodynamic sense. Moreover, they are fairly resistant to biodegradation by the native microorganisms, and persistent in the environment [7]. Damage caused by xenobiotic compounds poses significant health and ecological risks in developing countries [8]. The parent xenobiotic compounds are not directly toxic but they can be transformed into harmful oxy-radicals or carbon-centered radicals that attack the double bonds of cellular macromolecules generating oxidative damage [9]. Xenobiotic compounds have the potential to cause toxic effects on humans and animals with consequent acute carcinogenic, teratogenicity, and mutagenic effects [7]. Nonetheless, a diverse group of aerobic and anaerobic groups of bacteria often found in various habitats are capable of degrading xenobiotic compounds [10]. Several researches exist about biodegradation of xenobiotic compounds using dehalogenase-producing bacteria such as organofluorine [11,12], organochlorine [13,14], and organobromine [15,16]. Halogenated hydrocarbons are organic compounds that have many significant industrial applications such as multipurpose solvents, plasticizers, pesticides, fuel additives, flame retardants, and anesthetics [17,18,19]. Several halogenated hydrocarbon like polychlorinated biphenyl (PCB) residues and chlorinated hydrocarbon pesticide residues were detected in human adipose tissue, milk, and blood serum. Transfer and accumulation of these chemicals in the human body will consequently cause serious health problems [20]. One of the most well-known applications of halogenated aliphatics in the industry is related to the mixed substituted chlorofluorocarbons, CFC [21]. Millions of tons of halogenated aliphatics are produced annually and mainly have been used in a variety of manufacturing processes of solvents and cleaning agents [22]. These chemical compounds are common pollutants of aquatic habitats, as they are relatively water-soluble and can migrate to underground water-supplies and therefore threaten groundwater quality [23]. Haloacetic acids (HAAs) are recognized as oxidation products of airborne C\({}_{2}\)-halocarbons which have been demonstrated to be fast in volatilization [24]. They are carcinogenic in humans even at low concentrations [25]. Several studies show that haloacetic acids are biodegradable in anaerobic environments including soil and, wastewater, [26]. HAAs come either from brominated and/or chlorinated organic halogen compounds. These organic halogenated compounds are important by-products of the reaction between organic compounds present in water and chlorine in water-treatment plants [27]. There are five contaminating by-products of halogenated organic compounds, which exceed the maximum levels established by the US Environmental Protection Agency (60 ug\(\cdot\)L\({}^{-1}\)). These by-products include monochloroacetic acid (MCA), dichloroacetic acid (DCA), trichloroacetic acid (TCA), monobromoacetic acid (MBA), and dibromoacetic acid (DBA). As a result, the literature reporting on the analysis of HAAs mostly is focused on these five species [28]. TCA is a member of a very small group of \"moderately strong\" acids with ionization constants in the range 0.1-10 that is the most commonly used agent for chemical peeling [29,30]. TCA is one of the main contaminants of the environment that are carcinogenic to humans and animals [31]. The DCA and TCA are the most abundant HAAs detected in water resources containing nearly 80% of existing HAAs [32].