Biogenic FeS Accelerates Reductive Dechlorination Of Tetra-chloro-phenol By Shewanella Putrefaciens

Chlorophenols are carcinogenic,teratogenic,mutagenic,nonbiodegradable and highly toxic.Photo degradation is one of the most important natural degradation process of such substances in environmental waters.In this study,parachlorophenol was taken as a model pollutant.In order to improve the theoretical study on photodegradation behavior of chlorophenols in the environment,and provided reference to the prevention and treatment of waste water containing chlorophenols,the direct photolysis of parachlorophenol and photodegradation behavior with coexisting substances were studied.This paper uses Shewanella to compose FeS mineral,following the international standard test two valent iron method to study the influence of the number of ferric citrate,sodium thiosulfate and bacteria on the synthesis of FeS mineral and the surface properties of FeS minerals were compared by a series of characterization methods(SEM,XRD,XPS,TEM,etc.).The results show that at the higher concentration of sodium thiosulfate and iron citrate,the synthesis rate of FeS minerals is lower;The ratio of iron and sulfur atoms to the synthetic FeS mineral is 3.4,and the relative content of the surface active component FeS is 63.6%.The results of SEM and XRD show that the main components of the FeS minerals are amorphous FeS and the tetragonal pyrite with poor crystallization degree,The results of TEM showed that the biosynthesis of FeS structure is amorphous and fluffy,showed that the crystallization of FeS poor Shewanella initial synthesis.This study constructed an anaerobic condition for chlorophenol degradation system,studing the effect of different quantity of ferric citrate,sodium thiosulfate and bacteria number on the removal of chlorophenol.by analyzing the change of system pH,the production of acid and gas in the process of FeS synthesis,the change of bacterial aggregation and chloride concentration in the process of the degradation of P chlorophenol,studing the mechanism of dechlorination of FeS mineral to remove of chlorophenol.Research shows that,The mineral content of high biological FeS has a promoting effect on the removal of chlorophenol,Sodium lactate metabolism by Shewanella,produce acetic acid and small molecular products,and in the synthesis of FeS mineral process as a kind of excellent dispersing agents which have larger contact area and target pollutants.