| 摘要 |
Method and apparatus for treatment of wastewater sludges, particularly dilute sludges from biological or physical-chemical sewage treatment processes and having 0.7% to 3.0% dry solids. The wastewater sludges are mixed with at least four additives in a reaction tank (22), including a pathogen-killing agent (14), a chemical coagulating agent such as alum (16), a flocculating agent (18) such as an organic polymer, and a filter aid (20); coagulated particles are formed in the reaction tank into a large stable floc of gelatinous aggregates; a low-shear pump (24) transfers the suspended mixture in the reaction tank directly to a filter unit (57) without breaking down the flocculated gelatinous aggregates; and the suspended mixture is dewatered to form an effluent, and a manageable filter cake having the consistency of wet sand with 20% to 35% dry solids. Both the effluent and the filter cakes are decontaminated and detoxified for direct sanitary disposal without further processing. The system time requirements are less than 45 minutes from the input of the wastewater sludges to their discharge in the form of effluent and filter cakes. |
