利用可生物降解聚合物为碳源和生物膜载体脱氮及其动力学特性研究

Denitrification and Kinetic Characteristics Using Biodegradable Polymers as Carbon Source and Biofilm Carrier

以闭合循环养殖系统去除硝酸盐为目的,研究了以一种非水溶性可生物降解多聚物材料(BDPs)PBS颗粒作为反硝化碳源和生物膜载体的填料床反应器对于废水中硝酸盐的去除效果及动力学特征.结果表明,在温度为(29±1)℃,进水NO 3--N浓度为25～334 mg/L的条件下,进水NO 3--N负荷0.107～1.098 kg/(m3.d)为最适进水负荷.当进水负荷为1.098 kg/(m3.d)时,可达到最大NO 3--N体积去除负荷0.577 kg/(m3.d).进一步增加进水NO 3--N负荷则NO 3--N体积去除负荷开始下降.动力学研究结果表明,以PBS作为碳源和生物膜载体的反硝化速率遵循一级反应动力学.用Eckenfelder模型拟合,并求出常数n值和K值,建立的动力学模型采用该参数可以预测出水NO 3--N浓度.对模型的预测值与实际值采用统计软件SPSS16.0做方差分析表明,p>0.05,分别为p=0.553>0.05和p=0.632>0.05,模型预测值与实际值无显著性差异.

The PBS material that in the form of insoluble biodegradable polymers pellets was investigated as the solid carbon source and the biofilm carrier for nitrate removal from wastewater.The denitrification of nitrate removal and kinetic process were carried out in a packed-bed reactor in order to remove nitrate in recirculation aquaculture system.The experimental results indicated that the optimal influent loading rate was in the range of 0.107-1.098 kg/（m^3.d）,when the water temperature was（29 ± 1）℃ and the influent nitrate concentration was in the range of 25-334 mg/L.The maximum nitrate volumetric removal rate of 0.577 kg/（m^3.d） was achieved at the influent loading rate of 1.098 kg/（m^3.d）.When the influent loading rate exceeded 1.098 kg/（m3.d）,the nitrate volumetric removal rate was declined.The kinetic experimental results show that the denitrification rate of PBS as the solid carbon source and the biofilm carrier corresponds to first-order kinetics.Based on the kinetics characteristics,constants n and K used in Eckenfelder model were deduced,which can be successfully applied for the prediction of effluent nitrate concentration.The two groups’predictive values and actual values were analyzed by using SPSS 16.0 software for Paired-Samples t test analysis.The Paired-Samples t test analysis indicates that the corresponding p〉0.05 values are 0.553 and 0.632,which proved that no significant differences exist between the predictive values and actual values of the model.