Crude terephthalic acid production wastewater treatment system

Abstract

The invention discloses a crude terephthalic acid production wastewater treatment system. The treatment system comprises a treatment pond body, wherein a water inlet and a water outlet are formed in two sides of the treatment pond body, wastewater enters the treatment pond body from the water inlet, sequentially flows through a baffling adjustment region, a multi-layer filter system, an absorption region, a facultative anaerobic sedimentation region, a secondary sedimentation region and a water outlet region and finally flows out from the water outlet; a distillation tower is arranged below the absorption region, crystallization towers are arranged on two sides of the distillation tower, washing regions are arranged in the crystallization towers, an acid washing region is arranged below the crystallization towers, and a recrystallization chamber is arranged in the acid washing region. According to the crude terephthalic acid production wastewater treatment system, a treatment process is completed, the recovery efficiency of crude terephthalic acid is improved, the pollution coefficient is reduced, and meanwhile, the recycling and reusing of resources are realized; the crude terephthalic acid production wastewater treatment system meets actual use requirements.

Description

technical field [0001] The invention relates to a crude terephthalic acid production wastewater treatment system, which belongs to the technical field of wastewater comprehensive treatment in chemical equipment. Background technique [0002] Terephthalic acid, also known as p-phthalic acid, is the most productive dicarboxylic acid, mainly produced from p-xylene, and is the main raw material for polyester production. It is solid at room temperature, does not melt when heated, sublimes above 300°C, and can be melted at 425°C if heated in a closed container; hardly soluble in water at room temperature, mainly used to manufacture synthetic polyester resins, synthetic fibers and plasticizers, etc. . The purification method of crude terephthalic acid: including the following steps: drying crude terephthalic acid, ball milling, and sieving to make the particle size reach 1-5 μm, soaking in water at a temperature of 60°C-100°C, and stirring , clarification, then skimming, finally ...

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Problems solved by technology

Some domestic enterprises have implemented crude terephthalic acid recovery measures to greatly reduce COD, but the treatment process is not perfect, the recovered crude terephthalic acid has a small particle size (generally 5-10um) and is difficult to filter, and the water content is high (50% Above), high impurities, difficult to be directly used as chemical raw materials, wasting resources and affecting the environment

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