Sawai T, Sawai T, Shimokawa T
Radioisotopes. 1979 Jun;28(6):355-60. doi: 10.3769/radioisotopes.28.6_355.
The leachate generated from landfill contains humic substances such as humic acid and fluvic acid. It shows, in general, high chemical oxygen demand (COD) and biological oxygen demand (BOD), and colors in dark brown. When the leachate collected on the No. 15 landfill in Tokyo Bay was irradiated by gamma-rays from a 60Co source in bubbling air, the total organic carbon (TOC) decreased with increasing dose and the brown color was bleached. The effects of pH, flow rate, and dose rate on the decrease of TOC, the variations of UV spectrum, and the formation of carbon dioxide by the irradiation were examined. The decreasing rate of TOC increased with an increase of the flow rate up to approximately 1l/min and showed a maximum value in the region of pH 4 approximately 6. It was also dependent on the dose rate and increased with a decrease of the dose rate. The radiation chemical yield, G(--TOC), reached 162 at low dose rate of 1.3 X10(4) rad/h. This result suggests that a radiation-induced chain reaction occurred. The amount of TOC decreased was almost equal to that of carbon dioxide formed. This result shows that the organic substances were decomposed by irradiation to carbon dioxide as a final product and it was ejected from the solution.
垃圾填埋场产生的渗滤液含有腐殖酸和富里酸等腐殖物质。一般来说，它的化学需氧量（COD）和生化需氧量（BOD）较高，呈深棕色。当对东京湾15号垃圾填埋场收集的渗滤液在鼓泡空气中用钴60源发出的伽马射线照射时，总有机碳（TOC）随剂量增加而减少，棕色被漂白。研究了pH值、流速和剂量率对TOC减少、紫外光谱变化以及照射产生二氧化碳的影响。TOC的减少速率随着流速增加到约1升/分钟而增加，在pH值约4至6的范围内达到最大值。它还取决于剂量率，随剂量率降低而增加。在1.3×10⁴拉德/小时的低剂量率下，辐射化学产率G（-TOC）达到162。这一结果表明发生了辐射诱导的链式反应。TOC减少的量几乎与形成的二氧化碳的量相等。这一结果表明，有机物质通过照射分解为最终产物二氧化碳并从溶液中排出。
