Accelerating The Biodegradation Of Trichlorophenol And Sulfate Based On A Vertical Baffled Biofilm Reactor

With the development of modern industry,sulfate and chlorophenols are often used as auxiliary materials and chemical raw materials of process by paper mill and the dyeing factory,which makes the industrial wastewater not only rich in sulfate,but also in high concentration of chlorine phenol.On one hand,Chlorophenols is an non-degradation organic compounds characterized by macrocephaly,cancer and mutation.It will cause serious damages to human health and ecological environment,On the other hand,wastewater contained chlorophenols is more difficult to dispose because of the existence of sulfate.The mainly method to deal with chlorophenols wastewater and sulfate wastewater is biological treatment technology,which has the advantages of economic and easy-management.In the research,we use shake flask as biological responses and controling its opening time,to conclude the degradation condition of 2,4,6-TCP under the circumstance of anaerobic and partial anaerobic condition,then we adopt vertical flow biofilm reactor to deal with 2,4,6-TCP and explore the relation of 2,4,6-TCP and extra electron donor in the presence of sulfate,as well as the choice of external carbon source under the optimal condition.Results show that:1.Through the shake flake experimen,we find that the mechanism of 2,4,6-TCP is reductive dechlorination to transfer polychlorophenol into low chlorophenol,while low chlorophenols is hard to further biodegradation in anaerobic environment but can quickly achieve biodegradation when have some dissolved oxygen.Therefore,dealing with 2,4,6-TCP under anaerobic environment and then under aerobic can greatly improve the biodegradation rate of 2,4,6-TCP.2.The primary intermediate 2,4-DCP produced in the reduced dechlorination of2,4,6-TCP inhibit the biodegradation of 2,4,6-TCP in some degree;the secondary products 4-CP inhibit the biodegradation of 2,4-DCP to some extent too,while 4-CP has little influence in the biodegradation of 2,4,6-TCP.So,in the biological dechlorination process of 2,4,6-DCP,each intermediate product is gradually influence the next higher level one,not across level,therefore we can accelerate the biodegradation of 4-CP to gradually improve the biodegradation of 2,4,6-TCP.3.Putting sodium propionate which is easy to biodegradable,sodium acetate and glucose respectively as external carbon source in the experiment,we conclude that sodium propionate,sodium acetate and glucose all can greatly improve the reductive dechlorination of 2,4,6-TCP,and as extra electron donor,sodium propionate is more effective than sodium acetate and glucose in the process of sulfate reduction.On the other hand,the conversion of 2,4,6-TCP to 2,4-DCP is the highest,while converting to 4-MCP is the smallest when use glucose as electron donor,and if use sodium acetate instead of glucose as electron donor,the result is the opposite.4.With the amount of extra electron donor increased,the biodegradation rate of trichlorophenol and sulfate improved greatly,at the same time,when biodegradable2,4,6-TCP and sulfate,trichlorophenol reductive dechlorination and sulfate reductive have competitive relationship for electrons,and trichlorophenol reductive dechlorination have stronger affnity for electrons than sulfate.The optimal carbon source can be controlled around 1.08 mmol in the experiment adopting vertical flow biofilm reactor to degrade mixed wastewater with trichlorophenol for 50 ?M and sulfate for 0.28 mM.