Surfactant for sludge dewatering and sludge dewatering method

Abstract

The invention relates to surface active agent used for filthy mud dehydration. The addition of dodecyl benzyl dimethyl ammonium chloride is 1.42 to 2.07 percent by weight of the solid content of the filthy mud. The surface active agent has the advantages of low specific impedance value of the filthy mud after the surface active agent is added and high solid content ratio of filter mass after dehydration. In a method for filthy mud dehydration with the surface active agent, pressure filtration dehydration is carried out with a plate and frame filter press, the filthy mud injection pressure is progressively increased, the sewage and filthy mud to be regulated is injected into a filter press at certain injection pressure, and when the filter press is full, filtrate discharging flux is V1; when the filtrate discharging flux is lower than one half of V1, the filthy mud injection pressure is increased to a higher level, and the filtrate discharging flux is increased to V2; when the filtrate discharging flux is lower than one half of V2, the filthy mud injection pressure is increased to a higher level again, so that the filthy mud injection pressure is progressively increased to the preset pressure in this way, then feeding is stopped and the pressure is maintained, and finally the membrane extrusion is carried out. The method has the advantages of uniform increase of the density of mud cakes and small filtration resistance in filtration.

Description

technical field [0001] The invention relates to a surfactant and a sludge dehydration method for sludge dewatering, in particular to a quaternary ammonium salt surfactant and a sludge dehydration method for sewage sludge dehydration. Background technique [0002] The key to sludge treatment is sludge dehydration, which generally contains about 80% water. The water in sludge can be divided into four types according to its existing state: 1) interstitial water, which is free water surrounded by sludge particles, generally accounting for about 70% of the total water content of sludge; 2) capillary water, capillary water It is the water between the sludge particles or in the particle cracks that is combined with the sludge particles due to capillary action, accounting for about 20% of the total water; 3) Adsorbed water, which is adsorbed on the surface of the sludge particles due to the effect of surface tension Moisture, due to the small size of sludge particles, has a strong ...

AI Technical Summary

Problems solved by technology

[0020] In the dehydration method with patent No. 200610047281.1, the injection pressure during dehydration adopts a constant pressure working method, because the filter cake is in a very dense state when it is just formed, The filtration resistance increases, the filtration performance is low, and the water content of the sludge after final dehydration is 65% to 70% by weight

Images