3425 results about "Sewage sludge treatment" patented technology

An apparatus and method for treating organic waste sludge such as sewage sludge is disclosed wherein the sludge is first dewatered, moved to a day hopper for storage, and then successively passed through first and second reactors. As the sludge is passed through the first reactor, in a continuous fashion, the sludge and acid are thoroughly mixed and has the pH thereof substantially lowered due to the addition of acid in the first reactor. The sludge is then moved through the second reactor where the sludge is subjected to a base material to substantially raise the pH thereof. The treated sludge is then pumped from the second reactor to a pugmill and then to a dryer which dries the material. The dried material is then suitable for use as a fertilizer.

The invention provides supercritical dissolved air cavitation equipment and a method for reinforcing sludge reduction by adopting the same, belonging to the technical field of municipal sewage sludge treatment. The equipment is characterized in that when sludge flows through a shrinking spray pipe at a high speed, air is injected into a dissolved air cavitation cavity from an air suction pipe to be mixed with the sludge, then the air and the sludge enter a primary diffusion pipe and a secondary diffusion pipe in sequence and then are sprayed into an oxidation reaction kettle from cavitation nozzles, and finally the sludge subjected to dissolved air cavitation treatment is discharged from a sludge output pipe. The supercritical dissolved air cavitation equipment can operate in combination with a biochemical reaction tank, a reflux and excess sludge tank or a sludge homogenization tank. The equipment and the method have the beneficial effects that as a target vortex cavitation generator is combined with the oxidation reaction kettle, the conditions of supercritical wet oxidation reaction are achieved, the refractory organics in the sludge are directly decomposed into CO2, H2O and the like, and refractory organic macromolecular chains are broken into micromolecular chains and are further oxidized into fatty acids, so that the BOD (biochemical oxygen demand) / COD (chemical oxygen demand) ratio is increased, and favorable conditions are created for subsequent biochemical reaction, thus reducing the sludge; and after the equipment and the method are used by sewage plants, the sludge yield is reduced by 60-70%.