System for recycling PVA (Polyvinyl Alcohol) slurry from printing and dyeing wastewater and desizing wastewater

Abstract

The invention discloses a system for recycling PVA (Polyvinyl Alcohol) slurry from printing and dyeing wastewater and desizing wastewater. The system is characterized by comprising a reaction device, a solid-liquid separation device, a feed grinding device, a dehydration device and a discharge grinding device. The desizing wastewater is reacted and coagulated in a flocculent form in the reaction device, subjected to solid-liquid separation by the solid-liquid separation device, grinded by the feed grinding device, dehydrated and pressed into blocks by the dehydration device, and grinded by the discharge grinding device, so that the recycling of PVA is completed. The system disclosed by the invention adopts a chemical coagulation method, and recycles the PVA from the desizing wastewater through the units, such as a reaction unit, a solid-liquid separation unit, a grinding unit and a dehydration unit. The system has the capabilities of realizing the continuous treatment of the desizing wastewater, achieving a PVA recovery rate of 85-90% from the desizing wastewater, reducing COD (chemical oxygen demand) in the wastewater, largely lowering the loads of wastewater treatment facilities, effectively improving the biodegradability of the wastewater, and benefiting for the treatment of textile wastewater as well as the printing and dyeing wastewater.

Description

technical field [0001] The invention relates to a system for recovering PVA pulp from printing and dyeing desizing wastewater. Background technique [0002] The textile processing process is to spin the fiber into yarn and then weave it into cloth. Before the yarn is woven into cloth, the warp yarn must be sized to improve the strength and weavability of the yarn. Because PVA (polyvinyl alcohol) has good adhesion, size film toughness and wear resistance, it is widely used in the textile industry. However, the sizing material made of PVA has a high concentration of organic pollutants and is difficult to be biodegraded in the subsequent wastewater treatment, thus causing serious environmental problems. [0003] The treatment of desizing wastewater is mainly to solve the high COD content of PVA in desizing wastewater, which is difficult to biochemically treat and has high treatment costs, and brings serious environmental protection problems. With the announcement and implemen...

AI Technical Summary

Problems solved by technology

However, this kind of sizing material composed of PVA has a high concentration of organic pollutants and is difficult to be biodegraded in subsequent wastewater treatment, thus causing serious environmental problems.

[0003] The treatment of desizing wastewater is mainly to solve the high COD content of PVA in desizing wastewater, which is difficult to biochemically treat and has high treatment costs, and brings serious environmental protection problems

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