Experimental Research On Laccase Catalyzing And Oxidizing Estrone In The Water

Environmental hormones,refers to certain chemical substances released into the environment in the human production and life.These substances absorbed by human or any other creatures on the earth,play trogenic-like roles in their bodies,interfere with normal hormone secretion in vivo,and cause reproductive eventually malfunction.To now, there has been 50-70 chemical substances recognized as environmental hormone substances,including some typical pollutants like biphenyl A,DDT,and some natural estrogen like Estrone(E1),17α-Ethynyl estuarial(E2),ect.Natural estrogens such as E1 and E2 are considered important endocrine disrupting chemicals.Because E1 is more stable than E2,therefore,natural estrogens detected in wastewater from city sewage treatment plant is estrone.Even 0.001mmol / L low content of estrone,can lead to a significant reduction in reproductive functions,and improve the chances of women suffering from uterine cancer,ovarian cancer and breast cancer greatly, and do harm to people's health seriously.By means of laccase's strong catalytic and oxidative to phenolic substances,the program in this paper,is to estabilsh a reaction system of laccase catalyzing and oxidizing estrone,by using atmospheric oxygen as oxidant;to determine reaction conditions suitable for operation,by analyzing effects of pH,temperature,concentrations of laccase and reaction substrate concentration on the enzyme catalytic activity.This program establishes a Laboratory study foundation,for the establishment of reaction kinetic model,and the study of actual effect in wastewater treatment.Give a new method on the treatment of sewage containing environmental hormones;Offers theory evidence and reliable data to sewage treatment plant by using new technology on wastewater deep treatment.The paper mainly completed the following work:(1)estabilshed a reaction system of laccase catalyzing and oxidating estrone;(2)studied the effects of pH,temperature,concentrations of laccase and reaction substrate concentration on the enzyme catalytic activity,that is,effects on estrone removal ratio;(3) Determined appropriate operating conditions,when laccase is used to treat water containing estrone.he experimental results show that,laccase can effectively remove etrone contained in water,and has certain catalytic effect on estrone at a wide range of initial concentration.Suitable range of pH is 4-5,relative optimum pH value is 4.5 approximately; appropriate reaction temperature range is 22.5℃-27.5℃,relative optimum temperature is 25℃;Reaction speed correlates with the amount of laccase,a moderate increase of the amount of laccase,the reaction rate will speed up obviously.