改性枸杞枝作为反硝化脱氮碳源的研究

为提高枸杞枝作为反硝化碳源的效能，采用甲醇（体积占比分别为0、20%、50%、100%）-水-NaOH （0.01 g·mL^-1）体系（分别简称为0组、20%组、50%组、100%组）对枸杞枝进行改性处理，研究原枸杞枝的静态释碳、改性前后枸杞枝的静态反硝化特性、表面形态和脱氮动力学.结果表明，原枸杞枝释碳过程同时符合二级动力学方程和Ritger-Peppas方程；第I阶段（1~3 d）为碳源快速释放期，第II阶段（4~21 d）为碳源稳定释放期；改性后枸杞枝纤维素和半纤维素含量占比增加了8.7%~35.2%；不同甲醇-水-NaOH体系改性枸杞枝平均反硝化速率依次为20%组>50%组>0组>100%组>对照组，20%甲醇-水-NaOH组反硝化速率最高（0.76 mg·g^-1·d^-1），表明20%甲醇-水-NaOH （0.01 g·mL^-1）是枸杞枝改性的最佳条件；改性后的枸杞枝表面结构粗糙、不规则且有大量的孔洞产生，适合脱氮微生物附着生长，其反硝化脱氮过程符合Monod动力学方程（R²=0.96）.

Study on the modified Chinese wolfberry branches as carbon source for denitrification

The Chinese wolfberry branches were modified by the mixture of methanol (0, 20%, 50% and 100% volumetric ratio respectively, hereinafter referred as 0, 20%, 50% and 100% group), water and NaOH (0.01 g·mL^-1) to improve its denitrification efficiency as carbon source. The denitrification characteristics, surface morphology and denitrification kinetics of both raw and modified Chinese wolfberry branches, and the static carbon release characteristics of raw branches were extensively studied. The carbon release process of the raw branches fitted the second-order kinetic equation and Ritgre-Peppas equation quite well. Phase I (1~3 d) was the rapid carbon release stage, and Phase II (4~21 d) was the stable release period. The cellulose and hemicellulose content of the modified branches were 8.7%~35.2% higher than those of the raw branches. The average denitrification rates were in the sequence of 20% group > 50% group > 0 group > 100% group > the control group. The denitrification rate of the 20% group was the highest (0.76 mg·g^-1·d^-1), which indicated that 20% methanol-water-NaOH (0.01 g·mL^-1) was the optimum condition for the modification of the Chinese wolfberry branches. The surface of the modified branches was rough, irregular and had many voids, which was suitable for the growth of denitrifying microorganisms. The denitrification process of the modified branches followed the Monod kinetic equation (R²=0.96).