R & D of PCB Detoxification by Ultra-Violet Irradiation Generated by Poly-Phase AC Glow Discharge

利用自行研制的紫外光(UV)光源，对多氯联苯(PCBS)的光脱氯技术进行了实验研究。多氯联苯是一种有毒的有机氯废物，对地球环境有害，而且足够稳定，几乎不会被热或化学分解。所研究的方法可以在中等温度(&lt；50℃)和大气压下处理多氯联苯，对环境友好。在一个特殊的多极磁场中，多个电极之间的多相交流辉光放电可以有效地发射紫外光。光能利用率高，功率容量易于扩展，成本低。一种是，对于在矿物油中稍微混合(&lt；100ppm)的印刷电路板样品，紫外线脱氯是无效的。类似的石油已经作为大量的极地运输…的废油被大量持有更多电力公司的订货员。多氯联苯的脱氯被矿物油本身中断，矿物油本身吸收强烈的紫外光。另一种是，即使对于高氯化的印刷电路板样品，如果用异丙醇之类的溶剂很好地调节紫外光的传输长度，紫外光脱氯反应也几乎完全进行。由高氯联苯(&gt；70%)和氯代苯组成的类似样品一直被用作铁路公司列车变压器的绝缘油。样品溶液装在1升和10升两种体积的石英管容器中。将小容器插入直径10厘米、长50厘米的小型UV光源中。较大的放入直径20 cm、长70 cm的大源中。该小型光源由六极磁场中六相交流辉光放电产生，电极数为6个，氢气压力为0.1Torr。较大的一次是在12个电极的12极场中进行12相放电。由于多相放电电流现在可以连续，而不需要任何交流分断，所以发光是连续的，时间波动很小。此外，由于放电等离子体被有效地限制而没有端损，所以光被有效地发射出来，强度很强。在未来，我们将与两家公司进行验证，以便将我们的研究应用于实际应用。两家公司已经开发了使用紫外线脱氯和生物分解相结合的方法的多氯联苯脱毒中试工厂。较少

We investigated experimentally practical use of a detoxification technology of polychloride biphenyls (PCBs) by photo-dechlorination process with use of an originally developed ultraviolet (UV) irradiation source. The PCBs are one of toxic organic-chloride wastes, which are harmful to the earth environment and are stable enough to be hardly decomposed thermally or chemically. The studied method can process PCBs under a moderte (<50℃) temperature and an atmospheric pressure, which is friendly with the environment. The UV light is efficiently emitted from poly-phase ac glow discharges among multiple electrodes in a special multi-pole magnetic field. The light efficiency is high and the power capacity is easily enlarged with a low cost.We got two principal results from the experiments. The one is that UV dechlorination was not effective for a PCB sample which is mixed slightly (<100ppm) in mineral oil. The similar oil has been hold in abundances asa waste oil of huge number of pole transf … More ormers at electric power companies. The dechlorination of PCBs was interrupted by mineral oil itself which absorbs strongly UV light. The other is that UV dechlorination reaction proceeded almost completely even for a highly chlorinated PCB sample, if the UV transmission lenght is well adjusted by a solvent like isopropyl alcohol. The similar sample which is composed of highly chlorinated biphenyls (>70%) and chlorinated benzenes has been hold very much as insulation oil of train's transformers belonging to rail road companies.Sample solutions were contained in two kinds of a quartz tube container with a volume of 1 or 10 litter. The small container was inserted into a small UV light source with a diameter of 10cm and a lenght of 50cm. The larger one was set into a large source with a diameter of 20cm and a length of 70cm. The small light source was generated by a six-phase ac glow discharge in six-pole magnetic field with 6 electrodes at a pressure 0.1 Torr of H2 gas. The large one was by a twelve-phase discharge in twelve-pole field with 12 electrodes. Since the multi-phase discharge current can now continuously without any ac breaking, the light emission is continuously with small temporal fluctuation. Furthermore, since the discharge-plasma is effectively confined without end loss, the light is efficiently emitted with strong intensity.In future, we are going to corroborate with two companies in order to apply our study to practical use. The companies already developed a PCB detoxification pilot plant by using a combined method of UV dechlorination and biological decomposition. Less