Anaerobic Behavior Of Four Medical Glucocorticoids

Glucocorticoid is a steroid compound secreted by adrenal cortex,which can be mass-produced in artificial synthetic fashion and widely used in medical care.Owing to the unique physiological nature,glucocorticoid always be used in the treatment of inflammation,such as arthritis,asthma,bronchitis and so on.In recent years,the total sales of glucocorticoid drugs has been increasing,and more than 20% of the prescribed drugs that doctors prescribed glucocorticoid-like drugs in China.According to the investigation,there are more than hundreds of tons of glucocorticoid drugs which output annual among of China 's pharmaceutical products and most of the glucocorticoid drugs,widely used in the treatment of human diseases and livestock breeding.These glucocorticoids are excreted by the metabolism of the human body and the organism,and into the waste water discharged from the pharmaceutical factory eventually converge to the sewage treatment plant,the treated water is drained into the water environment,It might cause harms that the glucocorticoid in water absorbed by the organism.At present,glucocorticoid-like drugs have detected in sewage treatment plants and many areas of the water environment in China.Some of these glucocorticoids are natural,but some have been artificially synthesized by the pharmaceutical process.The most common method of treating organic pollutants with wastewater treatment plants is biological methodin China.Biological method is currently recognized as the most environmentally-friendly treatment to achieve the purpose of recycling,which not only can the organic pollutants in wastewater,but also,produce renewable energy with the degradation of pollutants,such as CH4?H2 and so on.At the early stage,,the research on glucocorticoid substances in domestic and foreign were mostly focus on medicine field,the research has just entered the initial stage in the field of environmental,and the study is mainly focused on environmental testing.Research shown that glucocorticoids can be degraded by microorganisms(such as Corynebacterium simplex,Rhodococcus equi,and Bacillus lipolyticus),while both of the ultimate degradation of glucocorticoid in anaerobic environments and the effects on microbial activity during anaerobic digestion have not been specifically studied.Therefore,this paper refers to the ECETOC test method,selecting the hydrocortisone,cortisone,prednisone,and dexamethasone,four kinds of medical glucocorticoids as research objects,to study their ultimatedegradation in anaerobic environment and anaerobic degradation process,the degree of inhibition of methanogen activity.1.In this paper,choosing four medical glucocorticoids: hydrocortisone,cortisone,prednisone,and dexamethasone,were used as test substances.The degradation laws of these four glucocorticoids were studied with reference to the ECETOC assay and the ISO international standard design test method.A comprehensive analysis of the net gas production,biogenic gas composition,VFAs and percentage of biodegradation can lead to the following conclusions:(1)It is difficult to degrade eventually with the hydrocortisone,cortisone,prednisone,and dexamethasone..Only a small amount of hydrocortisone,cortisone and prednisone are mineralized,and occurs degradation finally.However,dexamethasone only undergoes initial degradation and cannot be degraded finally,which will inhibit the production of endogenous biogas.With the increase of the concentration,the inhibitory effect decreases.(2)In the selected concentration range,the percentage of biodegradation of hydrocortisone and cortisone decreases as the concentration increases,and the percentage degradation of prednisone increases with the increase of concentration.At the concentration of hydrocortisone is 50 mg/L,the highest percentage of biodegradation is up to 20%.(3)When the concentrations below 100 mg/l,the anaerobic degradation of the four glucocorticoid hormones was hydrocortisone > Cortisone > Prednisone > Dexamethasone.2.Using glucose as a co-substrate,anaerobic ecotoxicity experiments were performed by adding hydrocortisone,cortisone,prednisone,and dexamethasone as the test substances in the culture medium.The experiment is based on the ECETOC assay and the ISO international standard design experiment method.By observing the effect of these four glucocorticoids on the activity of methanogens in anaerobic environment,the ecotoxicity rule of the four glucocorticoids can be judged.From the comprehensive analysis of cumulative gas production,net gas production,biogas components,volatile fatty acids,and relative activities,the following conclusions can be drawn:(1)The activity of dexamethasone and hydrocortisone on methanogenic bacteria It has a certain inhibitory effect and increases with the concentration.(2)Cortisone has an inhibitory effect on the activity of anaerobic microorganisms at the beginning stage,and the inhibitory effect is proportional to the concentration;after being adapted,it will have a stimulatory effect,and the stimulatory effect will decrease as the concentration increases;Pine at a low concentration will have an inhibitory effect on the activity of methanogens,and as the concentrationincreases,the inhibitory effect decreases.(3)Prednisone has a strong inhibitory effect on the activity of anaerobic microorganisms,and it increases with the increase of concentration.(4)At low concentrations,the inhibitory size relationship of the four glucocorticoids was prednisone> cortisone> dexamethasone>hydrocortisone.