The detection principle of COD and NH3-N is based on the optimization of reagent kits, while the selectivity and sensitivity of metal ions is mainly from Au nanoparticles. An excellent correlation of pollutant concentrations between the detected and verified ones is obtained, showing the feasibility of using this mobile automatic instrument for detection of COD, NH3-N and metal ions.

(1)To effective shorten the analytical time from 3 h to 15 min, which enhances the ability toward monitoring and auditing.
(2)The detection is based on the optimized reagents and the results are reliable and comparable to the standard method.
(3)Developed based on the microfluidic system and only 1 mL of wastewater is need for analysis.
(4)Can be customized according to the different needs, purposes and costs.

The developed technology is powerful on the examination of wide variety of water and wastewater. Since the detection only needs 15 min and 1 mL of sample, this cutting-edge technology can be applied to all kinds of industries and local government for auditing as well as for understanding the treatment performance of facilities. This technology can also be used to tract the possible pollution sources in river and natural water bodies.