An instrument for on-line chemical oxygen demand and nitrate in water monitoring

2016 ◽  
Author(s):  
Wei-Wei Feng ◽  
Dan Li ◽  
Zong-Qi Cai ◽  
Yong-Chun Zhang ◽  
Xiao Xu
2012 ◽  
Vol 41 (8) ◽  
pp. 883-887 ◽  
Author(s):  
冯巍巍 FENG Wei-wei ◽  
李玲伟 LI Ling-wei ◽  
李未然 LI Wei-ran ◽  
孙西艳 SUN Xi-yan ◽  
付龙文 FU Long-wen ◽  
...  

2012 ◽  
Vol 616-618 ◽  
pp. 1930-1934
Author(s):  
Mo Jie Sun ◽  
Xing Shuang Wei ◽  
Wei Zhang ◽  
Song Liu

The chemical oxygen demand (COD) is an important indicator of the characterization of organic substances in water content, reflecting the situation of water pollution. This system takes the IC, A/D and AT89C52 as key module, according to Lambert-Bill’s law and colorimetric principle, uses silicon photovoltaic cells and operational amplifier to realize photoelectric conversion. Incident light and transmitted light intensity of liquid are measured. The microcontroller can be automatically calculated the solution of the chemical oxygen demand (COD) value. The system also has real-time clock, over-range alarm and other functions.


2015 ◽  
Vol 73 (3) ◽  
pp. 697-706 ◽  
Author(s):  
Yingke Xie ◽  
Zhiyu Wen ◽  
Zhihong Mo ◽  
Zhiqiang Yu ◽  
Kanglin Wei

An automatic, miniature and multi-parameter on-line water quality monitoring system based on a micro-spectrometer is designed and implemented. The system is integrated with the flow-batch analysis and spectrophotometric detection method. The effectiveness of the system is tested by measuring chemical oxygen demand (COD) and ammonia-nitrogen in water. The results show that the modified system provides a cost-effective, sensitive, reproducible and reliable way to measure COD and ammonia-nitrogen in water samples with automatic operation and low toxic chemical consumption. In addition, the experiment results show that the relative error of the system is less than 10%, the limit of detection is 2 mg/L COD and 0.032 mg/L ammonia-nitrogen, respectively, and the relative standard deviation was 6.6% at 15.0 mg/L COD (n = 7) and 5.0% at 0.300 mg/L ammonia-nitrogen (n = 7). Results from the newly designed system are consistent with the data collected through the Chinese national standard analysis methods.


Sign in / Sign up

Export Citation Format

Share Document