Study On Removing Ammonium Nitrogen From Wastewater By Immobilized Microorganism And The Immobilized Carrier

Ammonium Nitrogen results in over- nurture of the obdurate water.For example,On the condition of limited fishery resources and cultivable water,the sustainable development of fisheries depends on aquaculture such as increasing intensity of cultivable water to elevate the output of per unit water. The high intensity of culture can adversely affect not only the aquaculture itself but also the accepted waters. For example ,the high concentration of total ammonia nitrogen derived from high rates of fish excretion and feed loading is a harmful factor that can restrict fish products and cause waters eutrophication.So it becomes more important to remove the ammonium nitrogen from wastewater.Immobilized microbes can be used to remove efficiently nitrogen ,phosphorous,COD and heavy metal in the water treatment of closed recirculating systems, this paper studys A technics was used to remove efficiently NH4 + -N in the water treatment and the capability of macromolecule material for immobilized carriers.It was mainly introduced immobilized microorganisms technology in the paper, the methods used for immobilized microorganisms and immobilized carriers. After compared some immobilized means and carriers, polyvinyl alcohol (PVA) mixed with additives as entrapment agent was chose for entrapping nitrobacteria to remove NH4 + -N in the experiment.By PVA crosslinked with boric acid method it was found that 1% sodium alginate, 4%SiO2, 0.3%CaCO3 were the good additives for PVA beads immobilized nitrifying bacteria. The beads had well mechanical intensity and diffusion characteristic.The optimal entrapment conditions were ensured by using cross-test, NH4 + -N removal efficiency as main factor and intensity as supplementary factor. The results indicated that 10% PVA, 32h crosslinked time, 1 vol. nitrifying bacteria in 2 vol. gelatin ,3% active carbon were the optimal conditionsIn addition,in order to enhance the stability and nitrobacteria concentration of mmobilized pellets, we made immobilized carrier with macromolecule material instead of the active carbon. We studied the capability of macromolecule material and the effect to nitrobacteria activate.