Abstract: A method and an apparatus for treating organic wastewater and sludge which remarkably reduce the generated amount of sludge at a much lower running cost, and which reduce the size and the capacity of the solubilization tank. The method and apparatus for treating sludge employs a biological treatment system, wherein a biological treatment of wastewater is carried out, and a solid-liquid separation unit for separating a solid from a liquid in the wastewater after the biological treatment, to obtain a treated wastewater and a sludge. The apparatus has a means for obtaining a withdrawn sludge from a part of the sludge and an alkali-treatment tank, wherein an alkali-treatment of the withdrawn sludge is carried out. The apparatus also has a biological solubilization tank which solubilizes the sludge after the alkali-treatment under an anaerobic, anoxic or microaerophilic condition, and a means for recycling the solubilized sludge to the biological treatment system.

Abstract: A method and an apparatus for treating organic wastewater and sludge which remarkably reduce the generated amount of sludge at a much lower running cost, and which reduce the size and the capacity of the solubilization tank. The method and apparatus for treating sludge employs a biological treatment system, wherein a biological treatment of wastewater is carried out, and a solid-liquid separation unit for separating a solid from a liquid in the wastewater after the biological treatment, to obtain a treated wastewater and a sludge. The apparatus has a means for obtaining a withdrawn sludge from a part of the sludge and an alkali-treatment tank, wherein an alkali-treatment of the withdrawn sludge is carried out. The apparatus also has a biological solubilization tank which solubilizes the sludge after the alkali-treatment under an anaerobic, anoxic or microaerophilic condition, and a means for recycling the solubilized sludge to the biological treatment system.

Abstract: A method and an apparatus for treating organic wastewater and sludge which remarkably reduce the generated amount of sludge at a much lower running cost, and which reduce the size and the capacity of the solubilization tank. The method and apparatus for treating sludge employs a biological treatment system, wherein a biological treatment of wastewater is carried out, and a solid-liquid separation unit for separating a solid from a liquid in the wastewater after the biological treatment, to obtain a treated wastewater and a sludge. The apparatus has a means for obtaining a withdrawn sludge from a part of the sludge and an alkali-treatment tank, wherein an alkali-treatment of the withdrawn sludge is carried out. The apparatus also has a biological solubilization tank which solubilizes the sludge after the alkali-treatment under an anaerobic, anoxic or microaerophilic condition, and a means for recycling the solubilized sludge to the biological treatment system.

Abstract: Provided are a method and an apparatus for treating organic wastewater and sludge, which remarkably reduce the generated amount of sludge at much lower running cost, and which get the size smaller the capacity of the solubilization tank. The method and apparatus for treating sludge has: an biological treatment system, which applies biological treatment to wastewater, a solid-liquid separation unit for separating a solid from a liquid in the wastewater after treating the biologically, to obtain a treated wastewater and a returned sludge. And the apparatus has means for obtaining a withdrawn sludge from a part of the returned sludge, an alkali-treatment tank, which applies alkali-treatment to the withdrawn sludge. The apparatus, also, has a biological solubilization tank, which solubilizes the sludge after treating the alkali-treatment under an anaerobic, anoxic, or microaerophilic condition, and a means for returning sludge to recycle the solubilized sludge to the biological treatment system.