Experimential Reserch On Removal Of Phosphorus In Waste Water With Modified Steel Slag

Water is a valuable resource which human relies upon indispensably. The water of perperson was quite scarce, and has been polluted quite seriously in our country. Particularly, lots of wastewater with nitrogen and phosphorus has been discharged into rivers and lakes directly in recent years, which usually causing eutrophietion and leading to the large-scale water bloom and red tide in majority of lakes and coastal waters of China, the water was seriously polluted and the sustainable development of economy was also restricted. Thus, the essential approach to solve the problem of water pollution and nourishment is seeking and developing some suitable innovative processes which could provide multi-benefit including high efficiency, low energy, and low operational fee.Steel slag is one kind of metallic oxide solid waste which contains Ca, Mg, Al, Fe , Si. It has multiaperture , big superficial area and fairly good adsorption function. According to statistics, it will bring 15%²0% steel slag when produced 1t steel. Recently, the steel slag is main used for aspects such as metallurgical industry , building material, highways build , agriculture and the the utilization rate of it only nearly 10% which much lower than developed countries at present. In recent years, the environmental value of steel slag being regarded highly gradually, there have more and more research reports on the steel slag processing waste water. Develop slag application in treating waste water would be one kind of economy and effective method which according with to abolish bringing useless principle under control, has great significance.The thesis study of the steel slag which produced by E Zhou City iron and steel company, it analyses the optimum condition of treating the waste water by steel slag and proposes pertinent solutions for modified, reseach the the best technological conditions of modified; studyed the optimum condition of treating the waste water by modified steel slag and the high-point effective of removing phosphorus; investigated the regeneration and the optimum condition of the steel slag, opening new doors for the steel slag's comprehensive utilization. The research by the thesis reaches the following conclusion:1) The steel slag has certain ability to remove the phosphate from the waste water. When the phosphorus concentration of the waste water is 10mg/l and the pH value is Weak acid and base , and the dosage of the modified steel slag is 1g/100ml, within 1 hour the concentration of residual phosphorus could be reduced to 0.1mg/l which is far lower than the state standards for waste water discharge, the removal rate of phosphorus has been achieved over 98% .2) Compared ability of removing the phosphate from the waste water of the modified method: HCl,CaCl₂,NaOH,Pyrogenation, Pyrogenation is the best method for modified, consider the technique and economy, choose 800℃is the best modified temperature and 1h is the best modified time.3) The modified steel slag has much more ability to remove the phosphate from the waste water than the steel slag. When the phosphorus concentration of the waste water is 10mg/l and the pH value is Weak acid and base , and the dosage of the modified steel slag is 0.5g/100ml, within 30min the concentration of residual phosphorus could be reduced to O.lmg/1 which is far lower than the state standards for waste water discharge , the removal rate of phosphorus has been achieved over 99%.4) Adopt Pyrogenation to regenerate after he slag adsorption is saturated. When the phosphorus concentration of the waste water is 10mg/l and the pH value is Weak acid and base , and the regenerative steel slag is 0.5g/100ml, within 15min the concentration of residual phosphorus could be reduced to O.lmg/1 which is far lower than the state standards for waste water discharge, The removal rate of phosphorus has been achieved over 99%.