以聚丁二酸丁二醇酯为碳源去除含盐水体硝酸盐及其动力学模型

以固体碳源反硝化工艺应用于闭合循环养殖废水的脱氮提供理论和技术参数为目的，研究了以一种非水溶性可生物降解多聚物材料（BDPs）聚丁二酸丁二醇酯（PBS）作为反硝化碳源和生物膜载体的填料床反应器对含盐水体硝酸盐的去除效果及动力学特征。结果表明：水力停留时间对NO3--N去除效果影响较大，NO3--N去除率随水力停留时间延长而提高。在温度为(29±1)℃，进水NO3--N质量浓度为25～236 mg/L的条件下，进水NO3--N负荷低于0.32 kg/(m3·d)时，NO3--N体积去除负荷随进水NO3--N负荷的增加呈线性上升；进水NO3--N负荷为0.32 kg/(m3·d)时达到最大NO3--N体积去除负荷为0.21 kg/(m3·d)；进一步提高进水NO3--N负荷则NO3--N体积去除负荷开始下降且出水中出现NO2--N积累。动力学研究结果表明以PBS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，求出反应速度常数K值和常数n值且相关性良好。采用该动力学模型参数可以预测出水NO3--N浓度并用于实际闭合循环养殖系统的工程设计和优化运行。

Kinetic model for nitrate removal from saline water using polybutylene succinate as energy source

The insoluble biodegradable polymers pellets that constituted with polybutylene succinate were investigated as the simultaneous solid carbon source and the biofilm carrier for the nitrate removal in synthetic saline wastewater. The denitrification performance and kinetic procedure were evaluated as plug-flow mode in order to provide the technical parameters for potential-applications in recirculating aquaculture system (RAS). The experimental results indicated that hydraulic retention time played an important role on the nitrate removal efficiency. The maximum nitrate volumetric removal rate of 0.21 kg/(m3·d) was achieved at an influent loading rate of 0.32 kg/(m3·d), when the temperature was (29±1)℃ and the nitrate concentrations of 25-236 mg/L, respectively. Under influent loading rate below 0.32 kg/(m3·d), the nitrate volumetric removal rate increased linearly with the influent loading rate, and the maximum nitrate volumetric removal rate was achieved at 0.21 kg/(m3·d) when the influent loading rate at 0.32 kg/(m3·d). Further increasing of loading rate results in the declined performance and nitrite accumulate in effluent, respectively. The kinetic results show that the denitrification procedure of polybutylene succinate as the solid carbon source and the biofilm carrier follow first-order rate. Based on the kinetics characteristics, constants n and K were deduced by used of Eckenfelder model, which could be applied successfully for the prediction of effluent nitrate concentration. The verification of kinetic model was demonstrated validly that could be applied for the design and management of the RAS.