应用质子变化滴定测量法监测氨氧化的化学计量关系

开发了一套监测批式废水生物处理系统质子变化的自动滴定测量装置.装置由批式反应器、数据自动采集与保存系统和药品自动投加系统组成.通过实际测量活性污泥氨氧化反应中氢离子产生量与氨消耗量的化学计量比值,考察自动滴定测量装置的测试精度.在1L的反应器中改变氨氮浓度(以N计)分别为1.67、3.33、8.33、16.66和30.00mg/L下实测比值与其理论值十分接近,相对误差在2.09%～6.34%之间;保持氨氮浓度16.66mg/L,在1、2、3和4L的反应器中实测比值相对误差在2.09%～-18.57%之间,随反应器体积增大而明显增大.反应器系统中的碳酸氢盐和氨盐缓冲体系,特别是在较大容积反应器中的滴定动态效应是导致测试误差的重要原因.研究成果为滴定测量方法在废水生物处理过程中监测质子变化提供了一种重要方法.

Monitoring the Stoichiometric Relation of Ammonium Oxidation with the Titrimetry of Hydrogen Ion Variation

A set of automatically titrimetric system to monitor the hydrogen ion variation during biological wastewater treatment process in a batch bioreactor was developed, which consists of a batch bioreactor, data auto-acquisition and preservation unit, and titrant auto-dosing unit. The accuracy of measurement for the system was evaluated by measuring the stoichiometric ratio of hydrogen ion production amount to ammonium consumption amount of ammonium oxidation in an activated sludge system. The ratios measured in a 1L bioreactor with NH⁺₄-N concentrations of 1.67, 3.33, 8.33, 16.66 and 30.00 mg/L as N respectively were very close to the theoretical value, and the relative errors were among 2.09%-6.34%. However, the relative errors in bioreactors of 1, 2, 3 and 4 L with NH⁺₄-N concentration of 16.66mg/L as N were among 2.09%- -18.57%, and increased significantly with accretion of the volume of bioreactor. The buffers of bicarbonate and the ammonium, especially the titrimetric dynamic effects in a larger bioreactor are the primarily factors resulting in errors. This study provides an important approach for monitoring hydrogen ion variation in the process of biological wastewater treatment by titrimetry.