| 1,2,4-TCB is one of chlorobenzene compounds. Due to properties of the chlorine atoms such as having higher electronegativity,difficult to occur the electrophilic reaction, relatively stable chemical properties, lack of the corresponding microbial degradation enzyme, chlorobenzene compounds can be stranded for a long time and easy in vivo enrichment, posing a serious threat to human health and ecological environment.At present, CBs are disposed of by physical methods and chemical methods which are asked complex operating conditions and high costs. These ways generally restricted in the practical application of the water and waste gas treatment project. The inducible enzyme formed by microbial method which make use of microorganism special domestication and natural variant can degrade CBs or partly convert them with low processing costs, and won’t produce secondary pollution, so this method gradually become the mainstream of the CBs governance.The current research on CBs degrading bacteria is focused on bacteria rather fungi. However, the ability of bacterial degradation of CBs is low and less tolerant to the environment. While the degradation abilityof fungi is much larger than bacteria and can survivein low temperature and partial acidic environment except that fungal growth rate is slower than bacteria. In addition, compared to bacteria, it is better for fungi to process hydrophobic and poorly water-soluble organic.This paper is aim to study many aspects of the fungi which can degrade1,2,4-TCB isolated from wastewater and chlorinated benzene sludge produced by a chemical plant, including the best bacteria culture time, optimal degradation conditions, the degradation rule of actual industrial wastewater, and metabolic intermediates, so It provides a theoretical basis for the microbial treatment of wastewater application of chlorinated benzene. Two straints of fungi degrading1,2,4-TCB were isolated and initially identified Penicillium and Trichoderma by optical microscopy. Two straints of fungi were called CBi and CB2.The experimental results show that the optimum culture time of Penicillium fungi is30hoursand the optimal degradation conditions is30℃, pH for6,5%of the inoculum size, rotation speed130r/min. Under optimal conditions, the rate of degrading1,2,4-TCB of the fungus is over85%(initial concentration is54.8mg/L).This fungus could make use of 1,2,4-TCB as the only carbon and energy source in the degradation process, after24hours, the degradation rate could reach88.5%, and the concentration of the remaining1,2,4-TCB is3.84mg/L(initial concentration is56.6mg/L). After the fungus was domesticated by the actual industrial wastewater in the pH range of5-8, the degradation rate of the actual industrial wastewater reached more than83%. The concentration of the remaining1,2,4-TCB is less than5.39mg/L(initial concentration is39.59mg/L), When Initial concentration of1,2,4-TCB is68.51mg/L in the actual industrial waste water, the degradation reaction of1,2,4-TCB by this fungi could be approximated as a first order reaction, and the reaction rate constant is0.1308h-1; and this fungus produced metabolites in the degradation process such as3-(4-chlorophenyl) acrylic acid, henol metabolism product, etc... |
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