Emission Characteristics And Treatment Methods Of Pollutants From A 57K Flat Panel Display Factory

With the rapid development of China's economy,China has overtaken Japan to become the world's second largest economy.The rapid economic development,huge market demand,relatively low labor price and other factors have gradually made China the world's largest production base for computer monitors,notebook computers and liquid crystal televisions and the largest consumer market for electronic products.This paper takes a flat panel display factory in Inner Mongolia as the research object.Through analyzing the production process of flat panel display in each production process segment and the pollution-producing Node graph in each process segment,the main pollutants in each node and their production situation,the pollution source of each pollution-producing node is determined through on-site data analysis.According to the characteristics of various pollutants,the main pollutant treatment measures are analyzed rationally,and an optimization scheme for the prevention and control of a certain characteristic pollutant is put forward.The analysis results show that in the production process of flat panel display manufacturing,inorganic waste gas is discharged after being treated by a spray washing tower,while organic waste gas is treated by a waste water rotating wheel+incineration method.Through various treatment measures,the waste gas treatment efficiency is more than 95%.The main pollutants of wastewater are pH,COD,BOD5,SS,F-,NH3-N,etc.The treatment process in the sewage treatment station of our factory can stably and reliably reach the standard for treating wastewater containing acid,alkali,phosphorus and fluoride.The total removal rate of major pollutants COD is more than 80%,the total removal rate of BOD₅ is more than 80%,the total removal rate of phosphate is more than 97%,and the total removal rate of fluoride can reach70%.Hazardous wastes in solid wastes are all entrusted to qualified disposal enterprises for disposal.Hydrofluoric acid,which is excellent in oxidation and corrosion in production process,is widely used in etching process.Therefore,waste gas and waste water generated in flat panel display manufacturing process contain high concentration of fluorine ions.Fluorine is a vital element,but excessive fluorine will lead to fluorosis.When the fluoride content in the atmosphere reaches 45-90mg/m 3,the leaf tissue of the plant will be necrotic.Excessive fluoride ions entering the water body will cause harm to human teeth,bones and reproductive system,also affect the absorption of phosphorus by plants,enhance the dissolution of metal aluminum in the soil,and cause double hazards of fluoride and aluminum to plants.According to the treatment process of waste gas and waste water,this paper puts forward the optimization scheme of fluorine-containing waste water treatment under the condition of low fluorine value,which can reduce the amount of sludge and the operation cost of the system on the basis of the water quality reaching the discharge standard.