Biodegradation Research Of Water Pollution With Nitrogenous Heterocyclic Compounds By Laccase-mediator-system

Nitrogen heterocyclic compounds is reported to be mutative, carcinogenic and difficultycapability of degradation. The component of actual wastewater is also complicated includingsome harmful inorganic compounds and organic compounds. In previous work, we have foundthat laccase can efficiently remove indole in the absabce of2,2′-azinobio-(3-ethylbenthiazoline-6-sulphonate)(ABTS). But transformation studies of indole with other pollutants coexisting in theliquid substrate by LMS have not been reported.In this paper, ammonia nitrogen and phenol were choiced as influence factors for analysisthe effect on the laccase activity. This showed that phenol had an inhibitory effect on the enzymeactivity. Ammonia nitrogen had a positive effect on the enzyme activity of laccase. Meanwhile,ammonia nitrogen was oxidized to nitrite.When useing ABTS as mediator, transformation of indole by laccase in the presence ofphenol or ammonia was studied. This showed that phenol and ammonia both could enhance thetransformation of indole. ABTS and phenol had significant effect on transformation of indole inthe liquid substrate. Ammonia had little effect on transformation indole.When using laccase alone, we had obtained the characteristics of indole transformation inthe presence of phenol or not. This showed that phenol could be oxidized by laccase substrate,and also enhance the removal of indole. The enzyme dosage and pH all had little effect on thetransformation of indole in the presence of phenol.Duing to the high expense of ABTS, we tried to find a new substrate to replace ABTS. Thisshowed that the white rot fungu’s fermented liquid could increase the removal rate of indole. Butthe effect is poor. Vanillin, p-coumaric acid, p-hydroxybenzoic acid, syringaldehyde had differenteffect on the removal of pyridine、indole and quinoline. The processes of treatment meet thefirst-order reaction in the absance of p-hydroxybenzoic acid.