According to the revised version of Waste Control Act to enter into force in 2017, Wastes could only be recycled assuming that the use of recycled wastes is safe for the environment and human health by environmental safety assessment. Even before this revision of the law, inorganic sludges could have been recycled as alternative materials for filler and cover materials by mixing with soil. However, in case of inorganic sludge from car-washing facilities, the revised law provides that the waste has to be landfilled. To assess the possibility of recycling this waste, we investigate the characteristics of the generation and concentration level of hazardous substances and evaluate the safety of recycling this material to assess whether this process meets the environmental standards. We obtained a total of eight sludge samples from car-wash shops, such as those in gas stations, car-repair shops and car-wash facilities. According to the results of leaching tests, most of the samples(8) fell under the detection limit and thus could be legally treated as general waste. However, in the results of contents some heavy metals, such as hexavalent chromium, lead, copper and zinc, exceeded the standards for soil contamination. We can conclude that the recycling of inorganic sludge from car-wash facilities could cause pollution in soil media when recycled and should not be recycled for filler and cover materials.

A lot of sludges occur during an activated sludge treatment process of the washing wastewater and by-product waste in the cuttlefish processing manufacture. The sludges give also out a bad smell, and their amicable reclamation is very difficult because of the limited area of the filling-up. To reduce the heavy weight and large volume of the sludges, they was burning up. After the burning up at 350℃ for 2hrs the weight(volume) of the sludges were reduced to 5% level of the initial value. In contents of the bad heavy metals for human after the burning up, cadmium and lead metal were slightly detected, while mercury and the bad others not detected.