Activated carbon filter treatment of laundry waste water in nuclear power plants and filter recovery by heating in vacuum Original Research Article

Laundry waste water including such organic compounds as surfactants is generated from washing workers’ clothes in nuclear power plants. An activated carbon filter (ACF) to remove them for water purification and vacuum heating (VH) treatment for the spent ACF recovery were studied. For the purification test, 2×10−2 m3 of simulated waste water (SWW) were circulated in an experimental apparatus at 1.5×10−3 m3/min, passing through the ACF (0.205×1.2 m) roll continuously, until total organic carbon (TOC) concentration was lowered from 100 ppm to 10 ppm. To measure TOC, 1×10−5 m3 of SWW were sampled every 10 min. After that, the ACF roll was removed and treated by VH at 800°C for 2 h. Then, the second allotment of SWW was introduced. The purification test was started again to check the VH effect. The dependence of ACF adsorption rate and amount adsorbed, on the recovery number was checked. It took about 5 h to lower TOC. This adsorption performance was recovered by VH treatment. The dependence of ACF adsorption rate on the recovery number peaked at 10 times, and then dropped gradually. In contrast, the adsorption amount of organic compounds was simply lowered. This was attributed to the effect of macropore length reduction being transiently larger than the influence of the specific surface area lowering.