Low-emission papermaking wastewater processing and comprehensive utilization method

Abstract

The invention belongs to the technical field of wastewater processing and comprehensive utilization, and discloses a low-emission papermaking wastewater processing and comprehensive utilization method. Residual papermaking wastewater, reused by plain boiled water in an inner production part, of paper machine net part plain boiled water is firstly subjected to fine fiber and filler recovery through an inclined wire and efficient shallow-layer air-flotation processing for producing corrugating base paper and bobbin paper, and the processed wastewater is subjected to on-line calcium removal to enter an UMIC anaerobic processing system to remove most parts of COD (Chemical Oxygen Demand); the processed wastewater is subjected to aerobic processing with an activated sludge method, and sludge processed by processing is used for making bricks after being subjected to filter pressing; aerobic processing reclaimed water is divided into three parts, wherein the reclaimed water 1 is mixed with the paper machine net part plain boiled water to be reused, the reclaimed water 2 is subjected to deep processing, and the reclaimed water 3 enters a city pipe network to be subjected to nanotube processing to be discharged. According to the method, the fresh water use amount of papermaking can be reduced, a wastewater emission amount is reduced, pollution discharge is lightened, the use efficiency of chemical additives in a production process is improved, and equipment corrosion is lightened.

Description

technical field [0001] The invention belongs to the technical field of wastewater treatment and comprehensive utilization, and in particular relates to a low-emission papermaking wastewater treatment and comprehensive utilization method. Background technique [0002] As we all know, the papermaking process consumes a lot of fresh water, discharges a lot of waste water, and causes serious pollution. With the continuous strengthening of people's awareness of environmental protection, the requirements for paper industry wastewater and pollution discharge are becoming more and more stringent. At present, the existing technologies of wastewater treatment in papermaking enterprises are mainly primary and secondary treatment, such as sedimentation or air flotation, anaerobic or aerobic activated sludge method, etc., because the treatment degree is not deep, the suspended solids and dissolved wastewater cannot be removed efficiently It is generally difficult to achieve a high propo...

AI Technical Summary

Problems solved by technology

At present, the existing technologies of wastewater treatment in papermaking enterprises are mainly primary and secondary treatment, such as sedimentation or air flotation, anaerobic or aerobic activated sludge method, etc., because the treatment degree is not deep, the suspended solids and dissolved wastewater cannot be removed efficiently It is generally difficult to achieve a high proportion of treated water reuse, and the wastewater discharged per ton of paper is generally more than 8-10 tons, so the problem of large wastewater discharge and heavy pollution load is still very prominent

Due to the use of sizing and various chemical additives in the current papermaking system, the pH value of the white water system is relatively low, generally between 5.5-6.0, which is relatively acidic. The use of chemical additives such as filters has a great influence on the effect. Due to the unsatisfactory effect, the amount of retention and drainage aids is large, which increases the cost of use and the pollution of discharged wastewater; the acidic white water system also affects the quality of paper products. , reduce the physical strength of paper products; increase the corrosion of equipment, and make the white water system smelly, polluting the operating environment

In the prior art, the utilization efficiency of biogas produced by anaerobic treatment of papermaking wastewater is not high, resulting in waste and environmental pollution; the papermaking sludge after aerobic treatment has a high water content and is difficult to dehydrate, which has also become a difficult problem in the treatment of papermaking solid waste

[0003] To sum up, the problems existing in the existing technology are: because the existing technology cannot efficiently remove the suspended solids and dissolved colloidal substances in the wastewater, the treated reclaimed water cannot replace the high proportion of clear water for reuse, and can only be discharged in large quantities. And there is the problem of ion accumulation in the papermaking system, which will seriously affect the operation of the paper machine and product quality

Therefore, in the prior art, the amount of clear water used in the production process is large, the waste water is discharged more, and the pollution load is heavy; the pH value of white water is low, the use effect of chemical additives such as retention and drainage aids is poor, and the acidification of the system is serious; the sludge in the secondary sedimentation tank and anaerobic treatment It is also difficult to comprehensively utilize the biogas

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