Recently, the Ministry of Ecology and Environment released two standards, “Water quality azide determination spectrophotometry (draft for comments)” and “Determination of water color chromaticity dilution method (draft for comments)”. Water quality-Determination of azides-Spectrophotometric method is the first release, which specifies the spectrophotometric method for the determination of azide in surface water, groundwater, domestic sewage and industrial wastewater. . The Water Quality Determination of chroma-Dilution multiple method specifies a dilution factor method for determining the color in domestic sewage and industrial wastewater. Since the date of implementation of this standard, the “4 dilution factor method” in the “Determination of water color chromaticity” (GB 11903-1989) approved by the former National Environmental Protection Agency on December 25, 1989 is in the corresponding environmental quality standards and pollution. Implementation of the emission control (control) standard is stopped.