Sludge dewatering high-alkalinity tail water treatment device and method

Abstract

The invention relates to a sludge dewatering high-alkalinity tail water treatment device. The device comprises a sedimentation tank a, a neutralization reaction tank a, a neutralization reaction tankb, a clean water tank, a sedimentation tank b, a spray dryer, a PLC control system, gas-liquid mixing equipment a, gas-liquid mixing equipment b, a pH meter a, a pH meter b, a dosing tank a, a dosingtank b, a dosing tank c, a screw pump, a CO2 supply system, a submerged pump a and a submerged pump b, wherein the sedimentation tank a, the neutralization reaction tank a, the sedimentation tank b, the clean water tank and the neutralization reaction tank b are sequentially connected; the dosing tank a is connected with a channel in front of the sedimentation tank a, and a polymeric ferric sulfate flocculant is contained in the dosing tank a; cationic polyacrylamide flocculants are contained in the dosing tanks b and c and are respectively connected with the sedimentation tanks b and c. Compared with an inorganic acid alkali reduction process, a CO2 alkali reduction device is more economical and environment-friendly, the operation cost can be reduced by more than 30%, the CO2 utilizationrate reaches 70% or above, meanwhile, calcium carbonate recovery is achieved, and clean production and resource recycling in the sludge dewatering industry are promoted.

Description

technical field [0001] The invention relates to the technical field of environmental protection, in particular to a sludge dewatering high-alkaline tail water treatment device. Background technique [0002] In the treatment of internal source pollution in rivers and lakes, the integrated treatment technology of sludge mechanical dehydration and chemical modification is often used to modify, dehydrate and solidify the dredged mud. During the chemical modification process, alkaline modification materials (lime, curing agent, etc.) are often added. , modifiers, etc.), resulting in a pH of about 12.5 in the filter press tail water. After the press filter tail water is mixed with the dredged mud supernatant, the general pH range is 11-13, the water volume variation coefficient is 2-4, and the tail water hardness > 500mg / L, SS>30mg / L. At present, the commonly used technology is to use inorganic acids such as hydrochloric acid and sulfuric acid to neutralize the mixed tail w...

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Problems solved by technology

However, since the inorganic acid is a strong acid, there are great potential safety hazards in storage and use; the amount of tail water from sludge dehydration varies greatly, and when the pH is about 8, it is difficult to adjust and control the pH, and quality accidents are prone to occur in engineering applications. - , SO 4 2- Ions cause a large secondary pollution to the environment; at the same time, the high alkaline tail water neutralization process consumes a lot of acid and high operating costs

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