多量程原位水质总磷总氮一体式在线监测仪

Multi-range In-situ Water Quality Total Phosphorus Total Nitrogen Integrated Online Monitor

针对地表水和城镇污水对于总磷(TP)总氮(TN)联合测定的需求,基于国标法提出了联合测定原理,利用顺序注射技术和微控技术建立水质总磷总氮多量程在线监测系统,完成了TP和TN的测定。总磷的测定量程分为0~1.2,1.2~2.5,2.5~5μg·mL^-1;总氮测定量程分为0~10,10~20,20~40μg·mL^-1。测定范围涵盖地表水环境I^V类水和城镇污水处理厂排放标准中总磷、总氮的标准限值。利用交替最小二乘拟合算法建立了总磷与总氮测定的回归模型。实验结果表明,其校正决定系数≥0.9964,最低检出限分别为0.01μg·mL^-1和0.05μg·mL^-1,重复性相对标准偏差(RSD)分别为1.36%~3.84%、0.78%~3.69%,贵州七大水库实际水样数据比对中,总磷相对误差≤±3.7838%,总氮相对误差≤±3.69%。系统运行稳定,可以精准、高效地分析不同地表水样的总磷总氮,为环境保护和污水排放提供了技术支持,尤其适用于实验室、站房式、便携式在线水质监测。

Aiming at the demand for joint determination of total phosphorus and total nitrogen in surface water and urban sewage,the principle of joint determination is proposed based on the national standard method. The sequential monitoring system and micro-control technology were used to establish a multi-range online monitoring system for total phosphorus and total nitrogen in water,and the determination of total phosphorus and total nitrogen index was completed. The total phosphorus index is measured in the range of 0-1.2,1.2-2.5,2.5-5 μg·mL^-1 . The total nitrogen index is measured in the range of 0-10,10-20,20-40 μg·mL^-1 . The measurement range covers the standard limits of total phosphorus and total nitrogen in the surface water environment I-V water and urban sewage treatment plant discharge standards. A regression model for determination of total phosphorus and total nitrogen was established by alternating least squares fitting algorithm. The experimental results show that the correction coefficient of the model is more than 0.996 4. The relative standard deviations of TP and TN repeatability were 1.36%-3.84% and 0.78%-3.69% respectively. Comparison of actual water samples in seven reservoirs in Guizhou,the relative error of total phosphorus is below ±3.7838%,the relative error of total nitrogen is below ±3.69%. The system runs steadily,and can accurately and efficiently analyze the total phosphorus total nitrogen index of different surface water samples,and provide technical support for environmental protection and sewage discharge,especially for laboratory,station type and portable on-line water quality monitoring.