GB/T 31195-2014

This standard specifies a chloride ion calibration method for determining chemical oxygen demand (COD) in wastewater with high chloride and high ammonia content. It is applied in environmental monitoring and industrial wastewater treatment contexts, particularly for effluents from chemical, pharmaceutical, and landfill leachate processes where conventional COD tests are interfered with by elevated chloride levels. The method ensures accurate COD measurement by correcting for chloride interference, enabling reliable assessment of organic pollution in these challenging water matrices.