New Method of Analyzing TOC by Efficient UV Oxidation and Turbidity Measurement

Abstract

Utilizing a U-shaped black light source designed to irradiate UV light in multiple directions and a fl at-type reactor made of fluorocarbon resin, we have proven that up to approximately 50 mg-C • L -1 of organic compounds can be completely decomposed to CO 2 . The optimum conditions were over 5,000 mg • L -1 of anatase-type titanium oxide, pH of 3-5, heating of the sample to 60-80℃, and circulation of 100-200 cm • min -1 of gas to increase the light exposure area and to suspend the titanium oxide inside the reactor. Also, the produced CO 2 was completely absorbed by alkaline 0.05-0.1 mol • L -1 strontium chloride solution, and measured as the turbidity of strontium carbonate particles. Adopting this new principle, we have produced a prototype of a compact and low-cost TOC analyzer, and have tested the performance for various organic compounds in solution, sewage, and industrial wastewater, for examples. By this measurement method, the amount of inorganic carbon in water can also be analyzed.

Evaluation of the Water-treatment Ability of Silica-doped Titanium Dioxide-coated Glass Plates Using a Cationic Coupling Reagent Based on a Flow Analytical System

“…24 The analyzer presented a linear range of between 3.0 and 30 mg L -1 and a limit of quantification of 3.0 mg L -1 for TOC measurements. In these experiments, two UV lamps emitting at 352 nm (National-FL20S-BLB lamp, Matsushita Electric Industrial Co., Ltd., Osaka, Japan) were arranged in parallel to generate a light irradiance of 2.0 mW cm -2 .…”