Study On Utilization System Of BaoSteel's Water Resource And Treatment Technology Of Manganese Mineral Biological Filtration For Factory Moat

At the background of water resource shortage, the development of iron and steel industry is limited by water supply insufficiency. According to the current situation of low efficiency of water resource recycling and high water consumption per ton steel, the study on the key technology of advanced treatment for integrated waste water reuse in iron and steel industry has been urgent affairs.The study focuses on research on water utilization system and treatment technology of manganese mineral biological filtration for factory moat, which can offer technical support for water saving work and construct high efficient water resource utilization system for other large-scale iron and steel enterprises in our country.The result shows, in Baosteel the level for water recycling could be top of china through the way of the quality of supply, water recycling and cascade water. Compared with advanced enterprise in the word, the water utilization system in Baosteel could be optimized through some ways.The methods includ increasing condense degree,optimizing the cascade water system,resuing factory moat, water pinch technology, gathering rain water and desalting seawater. The way of reusing the factory moat is the most economical.Through the investigation for the factory moat, Fe,Mn,Cl^-,SO₄^2-,Conductance and Rigidityare are the important water quality factors in reusing the factory moat.The study had done the experiment of iron and manganese removal by manganese mineral biological filtration . The result illustrates, Manganese sand comes from Gong Yi which particulate diameter ranges from 0.6 to 1.2mm, and biological filter height is 100cm. After biofilm is mature, the proper filtering velocity should be lower than 5m/h, work period is 4d, backwash intensity is 27L/(s·m²) and duration time is 5 min,DO concentration is between 4 and 5mg/L, the concentration of total iron and manganese in effluent could be lower than 0.3mg/L and 0.1mg/L,which meets the requirement for water quality in Baosteel.The study also had done the experiment of animalcules in the manganese sand column. The result shows, the microbial community is composed of biofilm and iron sludge .Two kinds of iron and manganese oxidizing bacteria are filtrated and nurtured, which belong to sheathed bacteria.The iron oxidizing bacteria amounts to 10³ï½ž10⁴ per gram dry sand in biofilm.Mixed bacteria has good effect of degradating Fe²⁺ and Mn²⁺,which follows different kinectics rules.The study puts forward some application ways for the technology of manganese mineral biological filtration in Baosteel. The factory moat could be treated and effluent of manganese mineral biological filtration could be mixed with industry water as the reuse water in industry water system. The wastewater of factory moat could be used as industry water directly after treatment by manganese sand filter and nanofiltration.The waterworks in Baosteel could construct a manganese sand filter tank to increase the effec of treatment.