利用淀粉/PCL共混物作为反硝化固体碳源和生物膜载体的研究

Denitrification Using Starch/PCL Blends as Solid Carbon Source and Biofilm Carrier

以双螺杆挤出机制备了淀粉/聚己内酯（PCL,polycaprolactone）共混物（SPCL5）,研究了其浸出性能及吸水性能,并在序批试验中研究了其作为反硝化固体碳源和生物膜载体的特性.结果表明,SPCL5颗粒前3d浸出的有机物浓度较高,随后逐渐降至1.31 mg/L.SPCL5颗粒吸水率在1d左右达到饱和,约为30.97％.SPCL5可作为固体碳源用于去除低碳氮比（C/N）水中的硝酸盐.以活性污泥接种时,SPCL5颗粒在1d后就有显著的脱氮效果.驯化结束后,SPCL5颗粒的平均反硝化速率（以N计）为0.020 8 mg/（g·h）.剪切力是影响反硝化速率的重要因素,转速从70 r/min提高至140 r/min时,平均反硝化速率提升近1倍,达到0.0403 mg/（g·h）.进水NO3-N浓度为15～50 mg/L时对反硝化速率无显著影响,反硝化为零级反应.红外光谱结果表明利用后的共混物中淀粉和PCL均发生了降解.

The starch/polycaprolactone （PCL） blends （SPCL5） were prepared by twin-screw extruder. The water absorption and leaching characteristics of SPCL5 were studied, and the feasibility and efficiency also investigated in batch experiment using SPCL5 as carbon source and biofilm carrier simultaneously. The results showed that a high release of DOC was observed during the first 3 d after leaching, and then DOC decreased significantly to 1.31 mg/L. The water absorption of SPCL5 was equilibrated in the l＇t d which reached 30.97%. SPCL5 could serve as solid carbon source for denitrification from low CIN nitrate-contaminated water. A high denitrification performance was observed after just 1 d acclimatization. After inoculation, the average denitrification rate of SPCL5 was 0. 020 8 nag/（ g. h）. Hydrodynamic shear force played an important role in denitrification process. The denitrifieation rate increased by about 100% when the rotating speed increasing from 70 r/min to 140 r/min. A negligible effect on denitrification rate was received when the influent concentration of NO3-N ranged from 15-50 mg/L, and the denitrification was a zero-order reaction. The IR analysis confirmed the biodegradation of starch and PCL in SPCL5blends.