A Novel Thermal Sensor for the Sensitive Measurement of Chemical Oxygen Demand

作者：Yao Na; Liu Zhuan; Chen Ying; Zhou Yikai^*; Xie Bin

来源：Sensors (Switzerland), 2015, 15(8): 20501-20510.

DOI：10.3390/s150820501

• chemical oxygen demand
• thermal sensor
• flow injection analysis system
• sodium hypochlorite

A novel rapid methodology for determining the chemical oxygen demand (COD) based on a thermal sensor with a flow injection analysis system was proposed and experimentally validated. The ability of this sensor to detect and monitor COD was based on the degree of enthalpy increase when sodium hypochlorite reacted with the organic content in water samples. The measurement results were correlated with COD and were compared against the conventional method using potassium dichromate. The assay required only 5-7 min rather than the 2 h required for evaluation by potassium dichromate. The linear range was 5-1000 mg/L COD, and the limit of detection was very low, 0.74 mg/L COD. Moreover, this method exhibited high tolerance to chloride ions; 0.015 mol/L chloride ions had no influence on the response. Finally, the sensor was used to detect the COD of different water samples; the results were verified by the standard dichromate method.

• 出版日期2015-8
• 单位华中科技大学; 湖北省疾病预防控制中心