Study On The Removal Of Nitrogen Pollution In The Water

Water pollution affect environmental quality has become a big problem, and the trendhas been intensified. A variety of toxic and hazardous water pollutants threaten human healthconstantly. Especially, the nitrate nitrogen, ammonia, nitrite hazards can’t be ignored. Inrecent years, the research for tri-nitrogen removal has become a hotspot. Nano-materials haslarge surface area, activity and other characteristics, which can quickly remove organics,nitrates and other pollutants, therefore it has gotten much attention. Studies have shown thatnano-iron has a higher removal for nitrate, but the primarily reduction product is ammonia,generation rate reach up to more than90%, but the initial reaction rate is not very high, andcan not adapt the removal for nitrate nitrogen with high concentrations. Therefore, theresearch will focus on the search for new materials or new ways to improve nitrate removalefficiency and reduce the formation of ammonia products.This paper focuses on new material graphene nano-iron load for research. On the basis ofcomparison with the effect of nano-iron,this paper study emphatically on the grapheneloading, initial concentration of nitrate-nitrogen, pH, dissolved oxygen and coexisting ionsand other factors on the removal effect, discuss the reaction mechanism for the removal ofnitrate with graphene nano-iron. Using the modified zeolite to adsorb ammonia products. Andon this basis to design a process for the treatment of the water with tri-nitrogen pollution.Following conclusions:（1）.Nitrate nitrogen removal was significantly higher than reduced iron. Reduced iron inacidic conditions can react with nitrates and nano-iron under neutral conditions have a goodresponse. Nanoscale iron removal efficiency in90minutes will be up to80%.（2）.The efficiency of graphene load nano-iron for the removal of nitrate was significantlyhigher than nanoscale iron, and ammonia generation rate is about79%, is lower than thenano-iron. The optimal load ratio of graphene and nanoscale iron is5:1; In the same dosage ofgrapheme load nano-iron, with the increase of initial concentration of nitrate nitrogen theremoval efficiency decreased; with the reduce of PH, to some extent can improve the removal efficiency: the greater the concentration of dissolved oxygen, graphene nano-iron on nitratenitrogen load removal efficiency is lower, it is because nano-iron is oxided by dissolvedoxygen, reducing the ability of the reduction for nitrate; coexisting ions Cl^-、SO₄^2-、PO₄^3-fornitrate removal have little effect, the impact decreasing order: PO₄^3-、SO₄^2-、Cl^-.（3） Scanning by electron microscopy the residual products of grapheme load nano ironand nitrate after0,30,90minutes. Found that the grapheme load nano-iron material is granularsphere. Particle size of about30⁷0nm, as the reaction proceeds, nano-iron graduallybecome flocculent material. After kinetic analysis showed that the reaction is not a simple firstchemical reaction, but a complex process consisting with chemical reaction, adsorption/desorption.（4） Design a process of specifically for the tri-nitrogen removal. Based on the sewagetreatment process, this process increases independence section for the tri-nitrogen removal.Simple, reliable, and using strongly.