A procedure has been developed for measuring by photometric method of mass concentrations of lignin substances. The measurement procedure is based on the ability of lignin substances to interact with nitrous acid thus forming nitrozo-derivatives. To assess the pollution of discharged waste and natural waters, calibration curves are plotted based on a series of samples prepared with the reference to the standard sample of lignin substances specific to the production facility.
The measurement technique helps to improve the environmental quality of waste water. It is in demand in the domestic and foreign markets of pulp and paper industry; it can be used for waste water treatment, in the assessments of pollution of natural waters, and for public supervision of the environment. The technique allows the measurement of mass concentration lignin substances to be carried out in the range of 0.5÷25 mg /dm3 in drinking and natural waters and in the range of 3÷100 mg / dm3 in purified water and sewage.
