两种释碳材料的制备及其性能研究

应用固定化技术制备了包埋淀粉的聚乙烯醇(PVA)释碳材料和海藻酸钠(SA)释碳材料,采用红外光谱和扫描电镜对其物化特性进行分析,研究了二者的释碳性能以及作为碳源对硝态氮的去除效果.结果表明,PVA释碳材料中淀粉混合较好,释碳过程满足二级动力学方程,单位质量材料释放的饱和COD达到99.60mg/(g·L).在温度为18~22℃,pH7.2~8.0,硝态氮浓度为35mg/L的条件下,PVA释碳材料的平均反硝化速率为18.5g/(m3·d),SA释碳材料的平均反硝化速率为15.5g/(m3·d),在稳定运行15d后,出水硝态氮浓度逐渐升高,脱氮效果开始下降.

Preparation and properties of two kinds of carbon releasing material

Two kinds of carbon releasing material containing starch were prepared with PVA (polyvinyl alcohol) and SA (sodium alginate) by immobilization technique. Fourier transform infrared spectroscopy (FTIR) was used to investigate the changes in characteristics of the two materials. Their surface and inside morphology were observed by scanning electron microscopy (SEM). Moreover, their COD releasing abilities were investigated. Starch was able to be mixed better with PVA than with SA. Carbon-releasing process of PVA material containing starch follows second-order kinetic equation, and the release curve displayed a better double-reciprocal relationship. The saturated COD concentration released from per gram PVA material was 99.60 mg/(g·L). The effect of the two materials as sole carbon source on denitrification efficiency was studied at 18~22℃ with initial NO3--N concentration of 35mg/L and pH of 7.2~8.0. The average denitrification dynamic rates were equal to 18.5 g/(m3·d)and 15.5 g/(m3·d) for PVA and SA material, respectively. A time-dependent decrease in nitrate removal efficiency was observed after 15 days.