Study On Enhancement Of Uranium(Ⅵ) Biosorption Bychemicallymodified Fungus Fusarium Sp.#ZZF51

With the rapidly development of industrialization, the emission ofwaste water in the environment is also rapidly increasing, which hasproduced very serious environmental pollution problems. The heavymetal pollution is one of water pollution in the environment, while in theheavy-metal pollution, radioactive pollution is top priority.It is well known that heavy metals are non-biodegradable and can beaccumulated in living organisms through food chains. Especially, theradioactive element uranium may make humans more likely to get cancer,suffer some chronic diseases, incur disability and even cause geneticdefect. Uranium waste water flows into the river, river, lake, sea, and soil,bringing harm to the environment and the human body. The concentrationof uranium in water is not the same for the different emission source, butits existence form similar, usually being in the form of UO2+2in theenvironment.At present, the most widely used removal methods, including ionchange, chemical precipitation, electrolysis, and membrane filtration,suffer some drawbacks, such as high operating cost, incompleteprecipitation, long cycle length, and causing second contamination.Biosorption, an emerginguranium (VI) removal technology from aqueous solution in recent years, has received widespread attention because of itsmany advantages like low cost, high efficient, selective adsorption,completely metal removal, available of large-scale applications and so on.The study was conducted according to the situation of treatment ofwastewater containing heavy metals at home and abroad and the basis ofothers’ researches, using formaldehyde, methanol, acetic acid, hexadecyltrimethyl ammonium bromide, pyromellitic dianhydride to chemicallytreat the south China sea mangrove endogenous fungi Fusarium sp.#ZZF51, obtaining five new biosorbents FB, MB, AB, CTAB-B andPMDA-B. The five kinds of biological adsorbent was studied in the staticadsorption of heavy metal uranium (VI), and the influencing factorsaffecting the biosorption removal rate has been explored to seeking thebest adsorption conditions for uranium adsorption. The adsorptionmechanism, adsorption model were explored, providing a reference forindustrial wastewater treatment. Results are as follows:(1) Optimum adsorption conditions. Experimental results show that themaximum biosorption capacity of formaldehyde-treated biomass foruranium (VI) at the optimized condition of pH6.0, S/L0.6andequilibrium time90min is318.04mg·g-1, and those ofmethanol-treated and HAc-treated biomass are311.95mg·g-1and351.67mg·g-1at the same pH and S/L values but differentequilibrium time of60min and90min, respectively. For CTAB-B and PMDA-B, the maximum biosorption capacity are399.16mg·g-1and229.45mg·g-1, respectively with the optimum pH7.0and5.0, thebest S/L0.6g·L-1and0.4g·L-1, equilibrium time120min and180min. Thus the maximum biosorption capacities of the five kind ofmodified biomass have greatly surpassed that of the raw biomass(21.42mg·g-1).(2) The study of kinetic exhibits a high level of compliance with theLagergren’s pseudo-second-order kinetic models for the fivesorbents FB, MB, AB, CTAB-B and PMDA-B, which shows thatchemical adsorption is the mainly part in the process of adsorptionreaction.(3) Langumir and Freundlich models have proved to be well able toexplain the sorption equilibrium with the satisfactory correlationcoefficients closer to1.00for FB、MB、AB、PMDA-B. While forCTAB-B, Temkin model exhibts a high correlation coefficients thanLangumir and Freundlich models.(4) Adsorption mechanism research. FTIR results of the modifiedbiomass and uranium-binded biomass show that the spectrum of-OH、C=O、P-O、N-H、C-N on the surface of the fungus has changeda lot, proving that the carboxyl, amino and hydroxyl groups areimportant functional groups in uranium biosorption procedure,which little changes can be found for C-N.