Recycling method of papermaking advanced treatment wastewater based on chemical decalcification

A technology of chemical decalcification and advanced treatment is applied in the field of advanced treatment of papermaking wastewater, which can solve the problems of recycling without advanced treatment, discharge of wastewater, waste of water resources, etc., so as to reduce the cost of membrane cleaning and regeneration and achieve good economic benefits. , the effect of reducing waste water discharge

Inactive Publication Date: 2013-08-28
BOYING XIAMEN SCI & TECH
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0015] The purpose of the present invention is to provide a chemical-based wastewater treatment method for the problems of high cost, low efficiency, mostly discharged wastewater after treatment, no advanced treatment and recycling, and waste of water resources in the existing papermaking wastewater treatment methods. The combination of decalcification technology, electrochemical technology and membrane technology has lower cost and higher efficiency, making it a recycling method for papermaking advanced wastewater treatment

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  • Recycling method of papermaking advanced treatment wastewater based on chemical decalcification

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Embodiment 1

[0042] 800 tons / day papermaking advanced treatment wastewater recycling method.

[0043] The water quality indicators of the papermaking advanced treatment wastewater were determined as shown in Table 1.

[0044] serial number project unit measured value serial number project unit measured value 1 COD Cr mg / L 150 4 Chroma 100 2 SS mg / L 120 5 Ca mg / L 400 3 Conductivity μS / cm 1600 6 hardness mmol / L 9.9

[0045] (1) Chemical decalcification

[0046] After the papermaking biochemical treatment, the effluent from the secondary sedimentation tank (that is, the papermaking advanced treatment wastewater) flows into the primary decalcification reaction tank through the pipeline, and first adds an appropriate amount of lime saturated solution to adjust the pH value to 8.5 through the dosing device under stirring to remove the false hardness ( bicarbonate), it flows into the secondary decalcification reaction tan...

Embodiment 2

[0061] 5000 tons / day papermaking advanced treatment wastewater recycling method.

[0062] The water quality indicators of the papermaking advanced treatment wastewater have been determined and are shown in Table 3.

[0063] serial number project unit measured value serial number project unit measured value 1 COD Cr mg / L 100 4 Chroma 150 2 SS mg / L 120 5 Ca mg / L 150 3 Conductivity μS / cm 1800 6 hardness mmol / L 4

[0064] (1) Chemical decalcification

[0065] After the papermaking biochemical treatment, the effluent from the secondary sedimentation tank (that is, the papermaking advanced treatment wastewater) flows into the primary decalcification reaction tank through the pipeline, and first adds an appropriate amount of lime saturated solution to adjust the pH value to 9 under stirring through the dosing device to remove the false hardness ( bicarbonate), it flows into the secondary decalcification react...

Embodiment 3

[0080] 20,000 tons / day papermaking advanced treatment wastewater recycling method.

[0081] The water quality index of the papermaking advanced treatment wastewater was determined as shown in Table 5.

[0082] serial number project unit measured value serial number project unit measured value 1 COD Cr mg / L 150 4 Chroma 120 2 SS mg / L 80 5 Ca mg / L 200 3 Conductivity μS / cm 1200 6 hardness mmol / L 5

[0083] (1) Chemical decalcification

[0084] After the papermaking biochemical treatment, the effluent from the secondary sedimentation tank (that is, the papermaking advanced treatment wastewater) flows into the primary decalcification reaction tank through the pipeline, and first adds an appropriate amount of lime saturated solution to adjust the pH value to 9.5 through the dosing device under stirring to remove the false hardness ( bicarbonate), it flows into the secondary decalcification reaction pool, and...

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Abstract

The invention discloses a recycling method of papermaking advanced treatment wastewater based on chemical decalcification. The recycling method comprises the following steps of chemical decalcification, filtering, electrolysis, membrane separation (ultra-filtration/MBR) and desalination. By combination of a chemical decalcification technology, an electrochemical technique and a membrane technology, 70-85% of papermaking advanced treatment wastewater can be recycled after being processed. Thus, wastewater emission is reduced; environmental pollution of the wastewater is avoided; waste of water resources is reduced; and the cost of regenerated circulating water is lower than the price of running water. Therefore, the recycling method is economical and reasonable; good economic benefit is generated; water consumption targets of tons of paper and wastewater discharge targets are greatly reduced; and the economic and technical indexes of enterprises are improved.

Description

technical field [0001] The invention relates to a treatment method for papermaking advanced treatment wastewater, in particular to a recycling method for papermaking advanced treatment wastewater based on chemical decalcification technology, electrochemical technology and membrane technology. Background technique [0002] Pulping and papermaking wastewater refers to the cooking waste liquid (also known as black liquor, red liquor) produced by chemical pulping, the middle water produced in the pulp washing and bleaching process and the white water produced in the papermaking process. Generally, 1t of organic matter and 400kg of alkalis and sulfides are dissolved in black liquor for every 1t of sulphate pulp produced; about 900kg of organics and 200kg of oxides (calcium, magnesium, etc.) in the liquid. The discharge of waste liquid into rivers not only seriously pollutes water sources, but also causes a lot of waste of resources. The paper industry is a traditional large wat...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C02F9/06C02F103/28
CPCY02A20/131
Inventor 张世文江中央陈艺许雅玲
Owner BOYING XIAMEN SCI & TECH
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