Deep treatment system and process for paper-making wastewater

Abstract

The invention discloses a deep treatment system and a process for paper-making wastewater. In the deep treatment system for paper-making wastewater, a bactericide dosing device is adopted to pump a bactericide to a raw water pump and a sucking hole in front of a return water pump which is connected with a return water pool respectively, the added bactericide can be uniformly mixed under the stirring action of the water pump, and the problem that use effect of the bactericide can be degraded when the bactericide is used in a pool is solved; in addition, the weak oxidation environment-friendly bactericide used in the deep treatment system and the process has the rapid degradation characteristic, is free of residue after being used, does not affect the application after the wastewater is treated and is free of drug resistance, and even if the bactericide is used for a long time, the content of microorganisms in white water is not greatly increased under the condition that the use amount of the bactericide is not changed. The deep treatment system disclosed by the invention is very high in treatment efficiency, that is, the designed capacity is 3000m<3>/d, and has the remarkable characteristics that the wastewater can be recycled in a quality-divided manner according to demands of water use sites, and the comprehensive wastewater recycling rate can be greater than 90%.

Description

technical field [0001] The invention relates to the field of papermaking wastewater treatment, in particular to a papermaking wastewater advanced treatment system and process. Background technique [0002] my country's paper industry wastewater discharge and COD discharge rank first in my country's various industrial discharges. The paper industry has the most serious pollution to the water environment. It is not only the primary issue of pollution prevention and control in my country's paper industry, but also the national industrial wastewater treatment standard. and water conservation are the primary issues. How to eliminate the pollution of papermaking wastewater and make use of the precious resources in the waste liquid is a work of great social significance and economic value, which should be attached great importance to. With the development of the economy, our country is increasingly facing the problems of shortage of fresh water resources and shortage of raw materia...

AI Technical Summary

Problems solved by technology

However, at present, about 50% of the total discharge from the papermaking industry has not yet been treated up to the standard, and the recycling of papermaking wastewater after treatment is even rarer. Therefore, the task of pollution prevention and recycling of papermaking wastewater is arduous

[0003] At present, there is a problem of insufficient treatment depth in the treatment of papermaking wastewater. Although the degree of pollution of wastewater is reduced to a certain extent, the treated papermaking wastewater is still dangerous to the environment and cannot be reused. Therefore, the preliminary treated wastewater is further treated. is of great significance

However, the traditional advanced treatment of papermaking wastewater has the following problems: 1. The degree of pre-treatment is not enough, which can easily cause clogging of ultrafiltration membranes and reverse osmosis membranes. The increase in cleaning frequency results in low wastewater treatment efficiency and reduces the use of ultrafiltration membranes and reverse osmosis membranes. life

2. The advanced treatment of traditional papermaking is all through reverse osmosis, resulting in a large amount of reverse osmosis concentrated brine (30%-40%), but due to the high salt content of concentrated brine, there are few usable points, which still causes a large amount of wastewater to be discharged into the environment

3. Traditional papermaking wastewater sterilization devices such as ultraviolet disinfection and adding sodium hypochlorite have low sterilization efficiency, and oxidative bactericides are harmful to papermaking equipment, chemical retention rate, and operator safety

In the papermaking process, adding too much oxidant not only leads to higher processing costs, but also increases the consumption of dyes and other wet-end additives (such as brighteners, sizing agents), increases corrosion, and shortens the life of the felt.

Some oxidants also lead to the formation of AOX

In addition, the excess addition of some oxidants is sufficient to control the microbial load in the liquid, but is ineffective in controlling the biofilm because it is difficult to penetrate into the biofilm matrix

[0005] The Chinese invention patent with the publication number of 103214154A discloses a regeneration and recycling device for advanced papermaking wastewater treatment, which is equipped with a chemical decalcification system, a multimedia filtration system, an electrolysis system, a biological aerated filter (BAF), and an ultrafiltration system. And the reverse osmosis system can effectively treat the wastewater in depth, so that the papermaking wastewater can be recycled. It uses the biological aerated filter to purify the wastewater, which takes up a relatively large space, and is selective for the killing of microorganisms. incomplete

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