A zero-discharge method for high-concentration wastewater

Abstract

The present invention relates to the field of industrial wastewater treatment, and specifically relates to a high concentration wastewater zero-emission method. According to the high concentration wastewater zero-emission method, nanofiltration, disc tube reverse osmosis (dt-ro) and evaporation crystallization are used for treatment of high concentration wastewater. Firstly the nanofiltration is used for removing hardness and other multivalent ions and some organic matters in wastewater, then the disc tube reverse osmosis (dt-ro) is used for deep concentration treatment of the high concentration wastewater with the hardness and some organic matters being removed, and salt solids in concentration water are crystallized by evaporation crystallization treatment of reverse osmosis concentration water after disc tube reverse osmosis deep concentration treatment, and then are concentrated for drying treatment. The disc tube reverse osmosis producing water and the evaporation and crystallization producing water produced in the treatment process both can be reused in the production process. According to the high concentration wastewater zero-emission method, the high concentration wastewater emission problem can be solved, meanwhile the recovery of water resources is maximized, and high concentration wastewater zero-emission is basically realized.

Description

technical field

[0001] The invention relates to the field of industrial wastewater treatment, in particular to a zero-discharge method for high-concentration wastewater. In particular, it refers to a zero-discharge method that uses membrane separation technology to treat high-concentration wastewater. More specifically, it relates to a zero-discharge method for treating high-concentration wastewater with "nanofiltration + disc reverse osmosis + evaporation crystallization". Background technique

[0002] In recent years, the high-concentration wastewater produced by petrochemical enterprises has become a difficult problem to deal with. This wastewater can neither be discharged nor reused, which has brought great troubles to various enterprises. Therefore, there is an urgent need to seek new separation technologies to solve the problem of treatment and discharge of such wastewater.

[0003] Nanofiltration (NF) is a membrane separation technology between ultrafiltration and r...

Examples

Embodiment 1

[0062] For a schematic diagram of the process, see figure 1 . The water quality characteristics of the high-concentration wastewater in this embodiment are: wastewater pH 7, conductivity 10000 μs / cm, COD cr 100mg / L, Na + 2000mg / L, Cl - 2500mg / L, total hardness (CaCO 3 )1500mg / L, SS100mg / L, dissolved silicon 50mg / L, NH 4 -N 50mg / L.

[0063] The steps of processing high-concentration wastewater by the zero discharge method of high-concentration wastewater of the present invention are as follows:

[0064] (1) Nanofiltration: The high-concentration wastewater enters the nanofiltration unit for nanofiltration treatment to remove multivalent ions such as hardness and some organic substances in the high-concentration wastewater. After separation and concentration by the nanofiltration unit, nanofiltration product water and nanofiltration concentrated water are obtained. The nanofiltration product water enters step (2) for treatment, and sodium carbonate is added to the nanofil...

Embodiment 2

[0080] For a schematic diagram of the process, see figure 1 . The water quality characteristics of the high-concentration wastewater in this embodiment are: wastewater pH 7.5, conductivity 15000 μs / cm, COD cr 300mg / L, Na + 3000mg / L, Cl - 3500mg / L, total hardness (CaCO 3 )2200mg / L, SS300mg / L, dissolved silicon 80mg / L, NH 4 -N 200mg / L.

[0081]The operation steps of embodiment 2 are the same as embodiment 1. Wherein, the difference from Example 1 is that sodium sulfate is added to the nanofiltration concentrated water to precipitate calcium ions, and the dosage of sodium sulfate is Ca 2+ : The molar ratio of sodium sulfate is 1:1; the supernatant of the remaining nanofiltration concentrated water is adsorbed by granular activated carbon, and the dosage of granular activated carbon is granular activated carbon:COD The mass ratio is 10:1;

[0082] In the above steps, the nanofiltration membrane module of the nanofiltration unit in step (1) adopts a sulfonated polyethersulf...

Embodiment 3

[0095] For a schematic diagram of the process, see figure 1 . The water quality characteristics of the high-concentration wastewater in this embodiment are: wastewater pH 8, conductivity 20000 μs / cm, COD cr 500mg / L, Na + 4000mg / L, Cl - 5000mg / L, total hardness (CaCO 3 )3000mg / L, SS500mg / L, dissolved silicon 100mg / L, NH 4 -N 500mg / L.

[0096] The operation steps of embodiment 3 are the same as embodiment 1. Wherein, the difference from Example 1 is that the nanofiltration concentrated water is added with a mixture of sodium carbonate and sodium sulfate for precipitation of calcium ions, and the dosage of the mixture of sodium carbonate and sodium sulfate is Ca 2+ The molar ratio of (sodium carbonate+sodium sulfate) is 1:1; the supernatant of nanofiltration concentrated water adopts powdered activated carbon for activated carbon adsorption, and the dosage of powdered activated carbon is powdered activated carbon: the mass ratio of COD is 8:1;

[0097] In the above-mentio...

technical field

[0001] The invention relates to the field of industrial wastewater treatment, in particular to a zero-discharge method for high-concentration wastewater. In particular, it refers to a zero-discharge method that uses membrane separation technology to treat high-concentration wastewater. More specifically, it relates to a zero-discharge method for treating high-concentration wastewater with "nanofiltration + disc reverse osmosis + evaporation crystallization". Background technique

[0002] In recent years, the high-concentration wastewater produced by petrochemical enterprises has become a difficult problem to deal with. This wastewater can neither be discharged nor reused, which has brought great troubles to various enterprises. Therefore, there is an urgent need to seek new separation technologies to solve the problem of treatment and discharge of such wastewater.

[0003] Nanofiltration (NF) is a membrane separation technology between ultrafiltration and r...

Examples

Embodiment 1

[0062] For a schematic diagram of the process, see figure 1 . The water quality characteristics of the high-concentration wastewater in this embodiment are: wastewater pH 7, conductivity 10000 μs / cm, COD cr 100mg / L, Na + 2000mg / L, Cl - 2500mg / L, total hardness (CaCO 3 )1500mg / L, SS100mg / L, dissolved silicon 50mg / L, NH 4 -N 50mg / L.

[0063] The steps of processing high-concentration wastewater by the zero discharge method of high-concentration wastewater of the present invention are as follows:

[0064] (1) Nanofiltration: The high-concentration wastewater enters the nanofiltration unit for nanofiltration treatment to remove multivalent ions such as hardness and some organic substances in the high-concentration wastewater. After separation and concentration by the nanofiltration unit, nanofiltration product water and nanofiltration concentrated water are obtained. The nanofiltration product water enters step (2) for treatment, and sodium carbonate is added to the nanofil...

Embodiment 2

[0080] For a schematic diagram of the process, see figure 1 . The water quality characteristics of the high-concentration wastewater in this embodiment are: wastewater pH 7.5, conductivity 15000 μs / cm, COD cr 300mg / L, Na + 3000mg / L, Cl - 3500mg / L, total hardness (CaCO 3 )2200mg / L, SS300mg / L, dissolved silicon 80mg / L, NH 4 -N 200mg / L.

[0081]The operation steps of embodiment 2 are the same as embodiment 1. Wherein, the difference from Example 1 is that sodium sulfate is added to the nanofiltration concentrated water to precipitate calcium ions, and the dosage of sodium sulfate is Ca 2+ : The molar ratio of sodium sulfate is 1:1; the supernatant of the remaining nanofiltration concentrated water is adsorbed by granular activated carbon, and the dosage of granular activated carbon is granular activated carbon:COD The mass ratio is 10:1;

[0082] In the above steps, the nanofiltration membrane module of the nanofiltration unit in step (1) adopts a sulfonated polyethersulf...

Embodiment 3

[0095] For a schematic diagram of the process, see figure 1 . The water quality characteristics of the high-concentration wastewater in this embodiment are: wastewater pH 8, conductivity 20000 μs / cm, COD cr 500mg / L, Na + 4000mg / L, Cl - 5000mg / L, total hardness (CaCO 3 )3000mg / L, SS500mg / L, dissolved silicon 100mg / L, NH 4 -N 500mg / L.

[0096] The operation steps of embodiment 3 are the same as embodiment 1. Wherein, the difference from Example 1 is that the nanofiltration concentrated water is added with a mixture of sodium carbonate and sodium sulfate for precipitation of calcium ions, and the dosage of the mixture of sodium carbonate and sodium sulfate is Ca 2+ The molar ratio of (sodium carbonate+sodium sulfate) is 1:1; the supernatant of nanofiltration concentrated water adopts powdered activated carbon for activated carbon adsorption, and the dosage of powdered activated carbon is powdered activated carbon: the mass ratio of COD is 8:1;

[0097] In the above-mentio...

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