缓释碳源净水基质吸附-生物协同脱氮的机理研究

Research on the adsorption-biological synergistic denitrification mechanism of slow-release carbon source water purification substrate

以聚乙烯醇(PVA)、海藻酸钠(SA)、玉米芯(Y)为原料制备了PVA-SA(基质Ⅰ)和PVA-SA-Y(基质Ⅱ),研究了缓释碳源净水基质的释碳性能、吸附性能、脱氮性能及机理。结果表明,基质Ⅰ、基质Ⅱ的释碳量分别为0.30~1.00、0.30~1.60 mg/g,平衡吸附量分别为0.317 8、0.9079 mg/g ,总氮平均去除率分别为10.90%、 32.40%,Y疏松多孔的结构特征是提高基质Ⅱ吸附、脱氮性能的关键,高通量测序结果表明基质Ⅱ中脱氮单胞菌属( Denitratisoma )、食酸菌属( Acidovorax )等与反硝化顺利进行相关的菌种比例较高。基于脱氮过程中COD、氨氮、亚硝酸盐氮、硝酸盐氮浓度的变化情况,提出了缺氧条件下基质的脱氮模型。根据模型计算,基质Ⅱ通过同化和反硝化削减的COD量与基质Ⅰ相似,通过吸附途径削减的氨氮比基质Ⅰ高11.2百分点,通过反硝化作用去除的硝酸盐氮比基质Ⅰ高43.0百分点。

The carbon release performance,adsorption performance,nitrogen removal performance and mechanism of polyvinyl alcohol (PVA)-sodium alginate (SA)(matrix Ⅰ) and PVA-SA-corn cob (Y)(matrix Ⅱ) were researched. The results showed that the range of carbon release concentration of matrix Ⅰ and matrix Ⅱ were 0.30- 1.00,0.30-1.60 mg/g,respectively;equilibrium absorption capacity of matrix Ⅰ and matrix Ⅱ were 0.317 8, 0.907 9 mg/g ,respectively;and the mean TN removal rate of matrixⅠ and matrix Ⅱ were 10.90% and 32.40%,respectively. The loose porous structure of Y played a significant role in improving the performance of adsorption and denitrification of matrix Ⅱ. And high-throughput sequencing results showed that the proportion of strains related to denitrification such as Denitratisoma , Acidovorax in matrix Ⅱ was higher. In addition,nitrogen removal model under hypoxia of matrix was proposed based on the change of COD,ammonia nitrogen,nitrite nitrogen,nitrate nitrogen concentration during the process of denitrification. According to the computation of the model,it was found that matrix Ⅰ and matrix Ⅱ had similar capabilities on reducing the amount of COD by assimilation and denitrification,but matrix Ⅱ had better capability on ammonia nitrogen removal by adsorption (11.2 percent points higher than matrix Ⅰ) and nitrate nitrogen removal by denitrification (43.0 percent points higher than matrix Ⅰ).