Investigation Of Sulfametoxydiazine Sodium Biodegradation By Phanerochaete Chrysosporium

With the wide using of antibiotic and abuses in human industry, a growing number of drug residues goes into environment leading to water pollution. The antibiotic could induce resistant bacteria which transferred resistance genes to pathogenic bacteria, therefore enhancing the resistance of pathogenic bacteria and harming people’s health seriously. So it is of the certain practical significance to study the removal of antibiotics in wastewater. The harm of SMD-Na could not be ignored for its low cost and wide using in clinical and breeding industry.The biodegradation of SMD-Na by phanerochaete chrysosporium was explored with shaking experiments and the concentration of antibiotics was determined by using high-performance liquid chromatography. Then the best condition of SMD-Na biodegradation was obtained through the optimization of culture conditions. Finally the biodegradation of antibiotics were studied using immobilized cultivation condition under different operating conditions for industrial application. The main results are as follows:1 、 Both the removal percentage were 10% under the condition of high temperature and deactivation as well as the blank control, while the biodegradation percentage of SMD-Na in the liquid medium was 80% after 10 days with the SMD-Na concentration of 10 mg/L. In the biotransformation process, lignin peroxidase obtained the maximal value 5 U/L in the eighth day and manganese obtained the maximal value 300 U/L in the sixth day. The biodegradation percentage of SMD-Na was only 50% after adding the P450 enzyme inhibitor.2 、 The best biodegradation conditions of SMD-Na were 10 g/L glucose, temperature of 35℃, speed of 150 rpm and the initial pH of 5.0. At the same time, the maximal value of manganese was 324.1 U/L and the biodegradation percentage of SMD-Na was 92% with the Mn2+concentration of 0.01 mmol/L. Much higher concentration of manganese ion could cause certain toxic to microorganism, and thus inhibiting biodegradation of antibiotics.3、The SMD-Na removal efficiency was 95.5% after two cycles of culture by immobilization culture in membrane reactor. When the hydraulic retention time was 24 h by sequencing batch culture, antibiotics degradation rate could increase to 95%. SMD-Na was degraded effectively in a cycle and the final degradation rate was nearly 80%. The change of SMD-Na concentration with time consisted first order kinetics equation...