Abstract: The present invention discloses a method of retreating a viscous semi-solid dewatered sludge having a water content of 70-85%, which is characterized by comprising the steps of: (1) adding a desiccant into said dewatered sludge, and stirring the resulting mixture to produce a mixed sludge having a water content of 50-60%; and (2) drying the mixed sludge to produce a dried granular sludge, which has a water content of 45% or less. The method of retreating the sludge of the present invention can decrease the treatment energy consumption, have a simple dry waste gas treatment, greatly reduce the cost for treating the sludge, accomplish the clean production and the sludge's innocuity, stabilization, minimization, and recycle.

Abstract: An air-drying device for sludge comprises at least one air-drying mechanism, a dosing mechanism, and a dehumidifying and heating mechanism. There two air-drying mechanisms. The dosing mechanism connects with the beginning end of the first air-drying mechanism (5) whose terminal end communicates with the beginning end of the second air-drying mechanism (8), with a discharge port (21) is arranged above the communicating position. The terminal end of the second air-drying mechanism communicates with the beginning end of the first air-drying mechanism to form a loop configuration. The device has high efficiency and low energy consumption. The detention time of the sludge in the drying device is adjustable so that the water content of the discharging material is adjustable.

Abstract: A method of integration of concentration-dehydration and aerobic air-drying of sewage sludge comprises the following steps: (a) conditioning by an organic agent (3); (b) gravitationally concentrating (5) the residual sludge conditioned by the organic agent; (c) conditioning by inorganic agents (7); (d) mechanically dehydrating (8); (e) crushing and dispersing (10); and (t) aerobically air-drying (11).