TWO-STAGE ADVANCED OXIDATION PROCESS AS AN ALTERNATIVE TO THE THERMAL AND UV PERSULFATE OXIDATION FOR TOC ANALYSIS

摘要

An online total organic carbon (TOC) analyzer, which uses a revolutionary oxidation process, is proving to overcome many of the recognized barriers associated with online TOC measurement. The analyzer uses a patented two-stage advanced oxidation technique as an alternative to the standard oxidation methods of thermal and ultraviolet (UV) persulfate oxidation. The sample is oxidized by hydroxyl radicals, which are created by exposing high pH reagents to ozone. The analyzer is designed to eliminate current difficulties encountered when determining TOC online. It can oxidize a very wide range of samples and effluents without any need for filtration. Samples are therefore fully representative. The process itself is a self-cleaning technology and it does not require any cleaning of the reactor or other wetted parts. The oxidation technique is also not affected by the presence of salts or calcium in the sample. It is possible to measure fatty and fibrous materials without any risk of clogging or contamination. The volume of the sample injected into the reactor of the analyzer is automatically adjusted for the optimum measuring range. The analyzer has three ranges, which can cover organic loads from 0 to 25,000 milligrams carbon per liter (mgC/1) with three different sample volumes. Prior to the oxidation process, total inorganic carbon (TIC) in the sample is removed by the addition of an acid reagent and is measured. The analyzer does not allow any TIC carryover to the TOC phase. Ozone is applied to a high pH reagent to produce hydroxyl radicals (a strong oxidizing agent), which are then used for the complete and effective oxidation of the sample. Acid is added to remove the total organic carbon content of the oxidized sample as carbon dioxide (CO2) gas. The carbon dioxide is then measured with an infrared detector. The analyzer does not require any calibration between services. The accuracy of the analyzer is ±3% of the reading or ±0.5 mgC/1. The analyzer helps to control and