水中总磷小型自动化检测系统的关键技术研究

Study on Key Technology of Automatic Phosphorus Detection System in Water

系统面向水中总磷的在线监测,对基于顺序注射-分光光度法的总磷小型自动化在线检测系统的关键技术进行了研究。系统由消解单元、流路单元、光学检测单元和控制单元组成。实验结果显示,系统在磷酸盐浓度为0.05～1 mg/L范围内有线性的光电压响应,灵敏度为0.850 2 V/(mg·L^(-1)),线性相关系数为0.999 9,检测下限为0.014 mg/L。可以实现对国家地表水环境质量标准中规定的I-V类水进行检测。此外,研究了环境温度对系统检测的影响,结果表明,在25～59℃范围内,随着环境温度的升高,检测灵敏度随之增加;当环境温度大于65℃时,检测的光电压信号产生畸变。研究结果对总磷的在线监测具有重要意义。

This system was aimed at the on-line monitoring of total phosphorus in water,and the key technology of the on-line detection system of total phosphorus based on sequential injection-spectrophotometry was studied.The system consisted of a digestion unit,a fluidic unit,an optical detection unit and a control unit.The results show that The detection system has a linear photovoltage response within the range of 0.05~1 mg/L phosphate concentration,the sensitivity of the detection system was 0.850 2 V /(mg·L^-1 ),the linear correlation coefficient was 0.999 9 and the detection limit was 0.014 mg/L.It can realize the detection of I-V water stipulated in the national surface water environmental quality standard.In addition,the influence of ambient temperature on the detection system was studied.The results show that the sensitivity of the test increases with the increase of the ambient temperature in the range of 25~59 ℃.When the ambient temperature is higher than 65 ℃,the detected photovoltage signal was distortion.The results of the study are of great significance to the on-line monitoring of total phosphorus.