Abstract
A flotation thickening method under decompression is one of the thickening methods of activated sludge in sewage treatment plants.The new method named as "the sludge supply after decompression" was proposed by one of authors.In the present study,the flotation thickening characteristics,that is,effects of MLSS(Mixed Liquor Suspended Solid) of activated sludge and absolute pressure in a vessel on height of supernatant liquor and treatment time were investigated using this method.As a result,height of supernatant liquor increased rapidly at first and then approached a constant with treatment time.Final height of supernatant liquor increased with decreasing absolute pressure,and decreased with increasing MLSS.Finished time of thickening did not depend on MLSS,but increased with absolute pressure.
