包埋型单宁酸铁制备及吸附催化脱氮性能研究

单宁酸铁(TA-Fe)具有吸附催化脱氮性能,包埋型TA-Fe可解决其固液分离问题。采用海藻酸钠(SA)制备包埋型SA/TA-Fe,并对其特性进行表征,同时评价SA/TA-Fe的吸附催化脱氮性能,以及制备条件对SA/TA-Fe的吸附催化脱氮性能的影响。结果表明,SA/TA-Fe具有明显孔隙结构且TA-Fe存在于孔隙表面,但比表面积明显下降。SA/TA-Fe对NH4⁺-N和NO₂^--N均具有吸附能力,但吸附能力低于TA-Fe,同时对NH4⁺-N的吸附能力大于NO₂^--N。包埋后TA-Fe对吸附NO₂^--N的影响更为显著。SA/TA-Fe对NH4⁺-N和NO₂^--N具有吸附催化能力,可同步提高NH4⁺-N和NO₂^--N的去除量。采用20 g/L的SA溶液,按照TA-Fe和SA质量比为2:1,交联时间为12 h,制得的SA/TA-Fe对NH4⁺-N和NO₂^--N的吸附催化去除效果最佳。

Preparation of Embedded Ferric Tannate and Its Absorption-Catalytic Nitrogen Removal Performance

Ferric tannate(TA-Fe)is proven to be able to removal nitrogen by absorption and catalytic ammonia oxidation.The embedded TA-Fe could make its solid-liquid separation easy.Embedded SA/TA-Fe was prepared by sodium alginate(SA)and its properties were characterized.The nitrogen removal performance of SA/TA-Fe by adsorption and catalytic was evaluated and the effect of preparation conditions on nitrogen removal performance of SA/TA-Fe was also investigated.The results showed that SA/TA-Fe had obvious pore structure and TA-Fe existed on the pore surface,but its specific surface area decreased significantly.SA/TA-Fe could remove both NH4⁺-N and NO₂^--N by adsorption,but its adsorption capacity was lower than that of TA-Fe.In addition,the adsorption capacity of SA/TA-Fe for NH4⁺-N was larger than that for NO₂^--N.The adsorption of NO₂^--N was influenced more after TA-Fe was embedded.SA/TA-Fe showed the adsorption and catalytic ability for NH4⁺-N and NO₂^--N,which could enhance the removal capacity of NH4⁺-N and NO₂^--N simultaneously.The optimal preparation conditions of SA/TA-Fe were determined as SA solution concentration of 20 g/L,a mass ratio of TA-Fe to SA of 2:1 and a cross-linking time of 12 h,the prepared SA/TA-Fe had the best adsorption catalytic removal effect on NH4⁺-N and NO₂^--N.