Abstract: Dioxins are eliminated from soot by conversion into oil and water. A gas stream of smoke and dioxin-entraining ash is passed through a curtain of water in a separator to separate the dioxin-entraining ash from the gas stream. The ash-water mixture is separated by a centrifuge, the separated ash is mixed with water and the mixture is again separated by a centrifuge into ash and an emulsion-like oil-water mixture in which dioxins are dissolved. This separated ash is also washed with water and the various wash waters and the dioxin-containing oil-water mixture are admixed and electrolyzed in a primary electrolyzer equipped with a carbon anode and a stainless steel cathode to decompose the dioxin components. The remaining aqueous liquid is electrolyzed in a secondary electrolyzer with an aluminum anode and a stainless steel cathode to generate hydrogen by electrolysis of water and metal hydroxides by electrolysis of aluminum.

Abstract: For eliminating dioxins from soot containing dioxins adhering to incineration ash by decomposing them, in an easy and simple manner and at low cost, into a harmless and useful oil and water and recovering the oil and water, a mixed gas 3 composed of smoke and dioxin-entraining ash is passed through a particulate matter separator 6, where the mixed gas passes through a curtain of water 5 to cause the dioxin-entraining ash to be taken up in water. The ash-water mixture is separated into ash and water on a centrifuge 12. The ash is washed with washing water 22 to elute the oleaginous dioxins entrained by the ash to give an emulsion-like oil-water mixture and the resulting mixture is separated, by means of a centrifuge 23, into ash and the emulsion-like oil-water mixture in which dioxins are dissolved. This ash is washed first with acidified water 26, then with alkaline washing water 28 and further with neutral water 29, followed by separation into moist ash and aqueous washings.

Abstract: A method and a system which enable simple and inexpensive removal of heavy metals from a heavy-metal-containing substance. In this method, a substance containing heavy metals and water are introduced into a mixing bath in proportions by weight of 1:3 to 1:6. A strong acid is added to the mixture, and the mixture is stirred while its pH is maintained at a pH lower than 4. As a result of stirring of the substance at a pH 4, heavy metals are extracted into the liquid as metal ions. The metal-ion-containing liquid is input to a heavy metal precipitation bath, and the pH of the liquid is increased to a pH higher than 10 by addition of alkali to the liquid. Gas bubbles of carbonic acid gas are input to the liquid from a lower portion of the heavy metal precipitation bath, and they are broken into a large quantity of small gas bubbles of carbonic acid gas by turbine blades. The large quantity of gas bubbles of carbonic acid are brought into contact with the metal-ion-containing liquid having a pH higher than 10.

Abstract: A positive electrode made of titanium having its surface electrolytically plated with platinum is disposed at the central position of an electrolytic ionized water producer. A cylindrical anion membrane is annularly arranged spaced from the positive electrode, a cylindrical cation membrane is annularly arranged spaced from the anion membrane, and a cylindrical negative electrode is annularly arranged spaced from the cation membrane. The opposite ends of the positive electrode, the anion membrane, the cation membrane and the negative electrode are watertightly closed with a base cover and a top cover, and a cylindrical first space is formed inside of the anion membrane. An annular second space is defined between the anion membrane and the cation membrane and an annular third space is defined between the cation membrane and the negative electrode. Water is introduced into the second space.

Abstract: A mixture of an oil sludge and an oil-contained waste water is first separated into a first oil-contained water and an oily dust containing metal-contained dust, fine metal powder and small fragments. Secondly, the oily dust is washed and separated into a harmless oil-free dust and a second oil-contained water containing the metal. Finally, both the first and second oil-contained water are separated into oil, harmless water and metal hydroxide by electrolysis. Thus, the mixture of the oil sludge and the oil-contained waste water is separated into components, which are in turn recovered, recycled, or converted into new materials, and the purification of the waste water can be realized.

Abstract: A mixture of an oil sludge and an oil-contained waste water is first separated into a first oil-contained water and an oily dust containing metal-contained dust, fine metal powder and small fragments. Secondly, the oily dust is washed and separated into a harmless oil-free dust and a second oil-contained water containing the metal. Finally, both the first and second oil-contained water are separated into oil, harmless water and metal hydroxide by electrolysis. Thus, the mixture of the oil sludge and the oil-contained waste water is separated into components, which are in turn recovered, recycled, or converted into new materials, and the purification of the waste water can be realized.