Study On Photoacoustic Spectroscopy And Sonoluminescence

Environmental pollution has become the most concerned issue to human being in the twenty-first century. Among all the pollution, air pollution and water pollution have been a direct threat to the world's economic and social development. Detection of gas concentration and water pollution has always been a concerned issue to the scientists of many countries.Acetylene is the main exhaust gas discharged into the atmosphere by human activities. As the characteristic gas of oil-filled power transformer, acetylene is the symbol of the fault condition. Acetylene is colorless, highly flammable at room temperature, and both physical and chemical properties are active. The leak of acetylene may cause damage and bad consequence to both electrical equipments and people. Detecting of the concentration of the acetylene is of great significance to human life and the safety operation of transformer.The history of photoacoustic is more than 130 years since it has been found in 1880. It is a trace gas detecting technology. and has many advantages, such as high sensitivity, wide detection range.etc. The laser beam is focused in the gas cell which is full of acetylene; the quartz tuning fork will sense the photoacoustic signal. The system is small, inexpensive and free of the background noise, which can be applied in varieties of fields by choosing proper light source.The wastewater of non-ferrous metallurgical industries is the source of the heavy metal pollution in the water. On the other side, sewage often contains a number of organic compounds. Atomic spectrometry and chromatography are the main methods used in water detection, which involved complex processing of samples. A method of detecting water pollution by using sonoluminescence is introduced and some results are showed and analyzed.