KR100374515B1 - Livestock wastewater treatment method and apparatus - Google Patents

Abstract

PURPOSE: Provided are a method and an apparatus for treating livestock wastewater, and more particularly for acquiring fertilizer using phosphorous and nitrogen contained in the livestock wastewater, and the method and apparatus are capable of reducing treatment cost by not using chemicals and preventing secondary pollution by the chemicals. CONSTITUTION: The method comprises the steps of adding dried straw to livestock wastewater by 18-32 wt.% with respect to the weight of the livestock wastewater; digesting the wastewater mixed with the straw at a temperature of 45-60°C for 15-20 days in anaerobic and high temperature condition in a digester, thereby producing carbon source in which phosphorous and nitrogen generated from digestion gas and remainder of digestion are collected; obtaining pure methane gas by passing the digestion gas through a loess layer or a caustic lime layer; and recycling the methane gas and the carbon source as heat to be supplied to the digester or a household boiler and fertilizer, respectively. The apparatus comprises a digester(200) connected to a wastewater tank(100) through a first pipe(120) and a heating line connected to a heat exchanger(400) installed around itself, a gas cleaning zone(300) with a filter being comprised of an activated carbon layer, a loess layer and a caustic lime layer for purifying digestion gas generated from the digester(200), thereby producing pure methane gas, and the heat exchanger(400) for supplying the pure methane gas generated from the gas cleaning zone(300) to the digester(200).