Process and reactor for anaerobic purification of waste water in a sludge-bed

摘要

In an anaerobic water treatment process, water (11) bearing a load of inorganic impurities is introduced to the lower region of a basin containing an agglomerated biological mass (7) of fluidised sludge forming a bed. A three-phase separation system (3): (i) holds back sludge, (ii) drains off treated water (63) and (iii) captures and taps off gas especially methane and carbon dioxide formed in the water treatment process. The novelty is that: (a) the gas is captured and drawn off by a number of gas capture hoods (40) located in the sludge bed; (b) the gas capture hoods (40) are arrayed in the same level providing almost complete coverage of the sludge bed; (c) not more than one third of the gas produced in the sludge bed escapes above the line of hoods to rise away from the sludge.