Treatment System for Soil Polluted by VCOCs Utilizing Photocatalysis

利用光催化技术处理 VCOCs 污染土壤的系统

基本信息

批准号：
15310047
负责人：
HASHIMOTO Kazuhito
金额：
$ 10.11万
依托单位：
The University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2003
资助国家：
日本
起止时间：
2003 至 2005
项目状态：
已结题

项目摘要

Volatile chlorinated organic compounds (VCOCs) such as trichloroethylene (TCE) and tetrachloroethylene (PCE) have been widely used as solvent for dry cleaning of clothes, washing of semiconductors, and so on. They have been disposed out of control, causing the soil and groundwater pollutions. These pollutions are serious environmental problems because these chemicals are carcinogenic and toxic. We have designed and proposed a treatment system for soil polluted by VCOCs utilizing "TiO_2 photocatalyst sheets". The sheet consists of TiO_2 powder and adsorbent (activated carbon). The adsorbent traps VCOCs evaporated from the soil and also traps undesirable intermediates such as phosgene and dichloroacetyl chloride (DCAC) observed by TiO_2-mediated photocatalytic degradation of TCE in gas phase.The system utilizing the photocatalyst sheets and solar light was investigated in the actual polluted field. One field was an old factory site, and the other was an active cleaning shop. The polluted … More soil in the old factory site was mixed with "Hotsoil (CaO)" to volatilize the chemicals (PCE), and the photocatalyst sheets were covered over the soil. As the status has been kept for three weeks, the photocatalyst sheets have illuminated by solar light for the period. PCE concentrations in gas phase of the soil decreased drastically for initial two days, and they were below detectable limit after seven days. The PCE concentrations in the soil were also below 0.01 mg/L whose concentration is Japan's environmental limit of PCE. The other system to treat the polluted soil under the ground in the active cleaning shop was an aspiration treatment of VCOCs gases from the polluted soil through the well by vacuum pomp. The aspirated gases were led to an adsorption device having the photocatalytic sheets. When the sheets saturated by VCOCs gas, we hanged out the sheets under solar light and reused them in the device. The results in the actual fields show that the system using photocatalyst sheets and solar light is effective on the treatment of the soil polluted by VCOCs. Less

挥发性氯化有机化合物（VCOC），例如三氯乙烯（TCE）和四氯乙烯（PCE）已被广泛用作衣服的偿付能力，清洗半导体等等。它们已经失控，导致土壤和地下水污染。这些污染是严重的环境问题，因为这些化学物质是致癌和有毒的。我们已经设计并提出了一种使用“ TIO_2光催化片”的VCOC污染的插座。该纸由Tio_2粉末和吸附剂（活性碳）组成。吸附剂捕获了从土壤中蒸发的VCOC，还捕获了不良的中间体，例如通过TIO_2介导的光催化降解的气相中的phosgene和二氯乙酰氯化物（DCAC）在气相中进行的TCE降解。该系统利用了PactatalyStalstystalystheStlesseets和Solar seal and pifted pifted pifted pifted pifted and pifted pifted。一个田地是一个旧的工厂地点，另一个是一家活跃的清洁店。被污染的……旧工厂场所中的更多土壤与“热土（CAO）”混合，以挥发化学物质（PCE），并在土壤上覆盖了光催化剂片。由于状态已保存了三个星期，因此在此期间，光催化剂纸通过太阳能照明了。土壤中的PCE浓度大幅度降低了两天，并且在7天后它们的限制低于可检测到的极限。土壤中的PCE浓度也低于0.01 mg/L的浓度是日本PCE的环境极限。在活跃的清洁店中处理地面下污染土壤的另一个系统是对VCOC通过真空蓬松的井中从污染土壤中的气体进行抽吸处理。吸气气体被带到具有光催化片的吸附装置。当床单被VCOCS气体饱和时，我们在太阳能灯下悬挂了床单，并将其重新放在设备中。实际领域的结果表明，使用光催化剂片和太阳光的系统有效地处理VCOC污染的土壤。较少的