Cd2+共存时镰刀菌(Fusarium sp.HJ01)降解对氯苯酚的特性与机制

为了解Cd2+对镰刀菌(Fusarium sp.HJ01)降解对氯苯酚(4-CP)的影响,研究了Cd2共存时,浓度、pH、碳源与氮源对镰刀菌降解4-CP特性的影响,并分析了其降解动力学与机理.结果表明,在降解温度、4-CP浓度等相同时,Cd2+共存对镰刀菌降解4-CP有一定的抑制作用.Cd2浓度小于3.O mg·L-1时,随着4-CP浓度的增大,镰刀菌对4-CP的降解速率变慢.镰刀菌降解4-CP的适宜pH为4.外加碳源蔗糖(3.Og·L-1)与外加NH4Cl(3.0 g·L-1)均使镰刀菌降解4-CP速度有所减缓.在Cd2+浓度0.1 ～3.0 mg·L-1时,镰刀菌降解4-CP符合零级动力学方程.Cd2+共存时只对4-CP的降解速率产生一定的抑制作用,而对其降解途径可能无显著影响.

Cd2+ impact on biodegradation of p-chlorophenol with Fusarium sp. HJ01

The effects of concentration, pH, carbon and nitrogen source on degradation of p-chlorophenol (4-CP) by Fusarium sp. HJ01 with co-existence of Cd²⁺ were investigated. The kinetic and mechanism of 4-CP degradation by Fusarium sp. HJ01 were discussed. It was concluded that cadmium (Cd²⁺) had a restraining effect on degradation of p-chlorophenol by Fusarium sp. HJ01 in the same temperature and concentration of 4-CP. The rate of 4-CP biodegradation with Cd²⁺ coexistence was decreasing with the increasing of 4-CP concentration while Cd²⁺ of concentration was less 3.0 mg·L^-1. The suitable pH for degradation of 4-CP by Fusarium sp. HJ01 was equal to 4. Addition of 3.0 g·L^-1 carbon (C₁₂H₂₂O₁₁) and nitrogen source could weaken the rate of 4-CP degradation by Fusarium sp. HJ01. The kinetic of 4-CP biodegradation could well accord with the zero order equation for 4-CP as the sole carbon source with 0.1~3.0 mg·L^-1 Cd²⁺ coexistence. Cd²⁺ could decrease the rate of 4-CP degradation, but might not change the pathway of 4-CP degradation.