A sensitive on-site visual method for determination of trace arsenic in groundwater based on molybdenum blue colorimetry combined with a membrane filtration technique was developed.

No abstract

No 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.

No abstract