Summary of the invention
The object of this invention is to provide a kind of membrane technique and process the method for crushed coal pressure gasifying process spent water,
For achieving the above object, the technical solution used in the present invention is as follows:
Membrane technique of the present invention is processed the method for crushed coal pressure gasifying process spent water, comprises the steps:
(1) first remove mechanical impurity through mechanical filter and secondary filter from the process spent water of phenol ammonia recovery unit discharge, prevent film result in blockage or damage;
(2) process spent water after filtration adds alkali adjusting pH value to 9 ~ 10.5, makes the phenols in sewage form phenol negative oxygen ion, prevents film to cause dirty blocking up, and then removes most phenols and other organism in sewage by two to three grades of film systems;
(3) fresh water that step (2) is discharged adds acid for adjusting pH to 6 ~ 8, makes free ammonia form ammonium salt, removes the most ammonia nitrogens in sewage by final stage film.
The film adopting in step (2) is reverse osmosis membrane or nanofiltration membrane.
Described mechanical filter adopts vertical mechanical strainer, and filtrate is selected quartz sand, has unique water distribution uniformity mode, makes strainer reach maximum efficiency, can meet for a long time effluent quality requirement.
It is the filler particles scratching film surface that prevents leakage that described secondary filter adopts the effect of accurate filter, and filtering accuracy is 5 μ m, and filter core is PP cotton or wire-wound filter core.
Below the present invention is elaborated:
The waste water that crushed coal pressure gasifying produces is after phenol ammonia recovery unit reclaims most of tar, middle oil, crude phenols and ammonia, then separate to level Four film system by three, remove phenols and ammonia wherein, the fresh water that produces carries out reuse, and dense water cycle is to phenol ammonia recovery unit entrance or for the preparation of coal water slurry.
Process crushed coal pressure gasifying process spent water with membrane technique and face maximum problem and be that the low-pole organism in waste water is easily adsorbed on film, film is caused dirty stifled, film is cleaned too frequent, device cannot steady running and is had a strong impact on life-span of film.Analysis to crushed coal pressure gasifying sewage composition shows, organism is wherein mainly various unit phenol and polyphenol, and phenols is slightly acidic, under sour environment, exist with phenolic hydroxyl group (ROH) form, under alkaline environment with phenol negative oxygen ion (RO
-) form existence.The present invention utilizes this character, adds the pH value of alkali adjusting sewage in the ingress of one-level film, makes the phenols negative ionization in sewage, and polarity specific ionization phenol significantly strengthens, and greatly reduces the adsorption to film, thereby has effectively prevented that the dirt of film is stifled.But because one-level film ingress adds alkali, the ammonia in sewage exists with free ammonia form, and film is very poor to the removal effect of small molecules free ammonia, the present invention, in final stage film entrance acid adding, makes the free ammonia in sewage form ammonium salt, is easy to tunicle and removes.Sewage is after two to three grades of films, and most phenols are removed, and now acid adding reduces pH value again, can not cause film dirty stifled.
The invention discloses membrane technique and process the method for crushed coal pressure gasifying process spent water, can effectively solve the problem that high-concentration phenolic wastewater biochemical treatment difficulty is large, investment is large, running cost is high producing in crushed coal pressure gasifying process.Crushed coal pressure gasifying process spent water first passes through gas liquor tripping device and phenol ammonia recovery unit, reclaim wherein after most of tar, middle oil, crude phenols and ammonia, pass through again mechanical filter and secondary filter, then separate to level Four film system by three, remove phenols and ammonia wherein, the fresh water that produces can be back to circulating water system or other user, and dense water cycle is to phenol ammonia recovery unit entrance or for the preparation of coal water slurry.Embrane method is processed crushed coal pressure gasifying process spent water and is had advantages of that investment is little, running cost is low.
Embodiment
Embodiment 1
As shown in Figure 1, membrane technique of the present invention is processed the method for crushed coal pressure gasifying process spent water, and concrete implementation step is as follows:
1, as follows from the process spent water index of phenol ammonia recovery unit discharge:
CODcr:3000 ~ 4500 mg/l, phenols: 800-1200mg/L, NH3-N:150~250 mg/l, oils: 200 mg/l, temperature: 35 ~ 45 DEG C, pH value: 7.0 ~ 9.5.
2, process spent water is first removed mechanical impurity through mechanical filter and secondary filter, prevents the film of rear system result in blockage or damage.
Described mechanical filter adopts vertical mechanical strainer, and filtrate is selected quartz sand, has unique water distribution uniformity mode, makes strainer reach maximum efficiency, can meet for a long time effluent quality requirement.
It is the filler particles scratching film surface that prevents leakage that described secondary filter adopts the effect of accurate filter, and filtering accuracy is 5 μ m, and filter core is PP cotton or wire-wound filter core.
3, the process spent water after filtration adds alkali adjusting pH value to 9.5, then enters one-level low-pressure membrane (one-level A), is separated into one-level A fresh water and the dense water of one-level A, and the dense water of one-level A enters the concentrated film (one-level B) of one-level, is separated into one-level B fresh water and the dense water of one-level B.Remove most of phenols in sewage by one-level film, the effect that one-level film entrance adds alkali has two, and one is to prevent that sewage from causing dirty blocking up to film, and another is to be more conducive to removing of phenols.
4, one-level A fresh water and one-level B fresh water enter secondary film after merging, and further remove phenols, are separated into the dense water of secondary fresh water and secondary, and secondary concentrate recirculation is to one-level low-pressure membrane entrance.
5, secondary fresh water adds acid for adjusting pH value to 6.5, then enters three grades of film removal of ammonia and nitrogen, is separated into final fresh water and three grades of dense water.The effect of acid adding is for the free ammonia in water is converted into ammonium ion, thereby removes.
One-level low-pressure membrane and one-level concentrate HL8040 film or the ESNA1-K1 film of Hydranautics company product, the AD8040 film of secondary film, three grades of films employing GE products or the SWC film that Hydranautics company produces that film adopts GE company to produce.
Final fresh water index is as follows:
Sequence number |
Project |
Numerical value |
Sequence number |
Project |
Numerical value |
1 |
pH |
6~8 |
7 |
COD(mg/L) |
40 |
2 |
Colourity |
10 |
8 |
NH3-N(mg/L) |
5 |
3 |
Electricity is led (μ s/cm) |
<50 |
9 |
SO
4 2-(mg/L)
|
<20 |
4 |
Turbidity (mg/L) |
Do not detect |
10 |
Na
+(mg/L)
|
<10 |
5 |
Cl
-(mg/L)
|
<10 |
11 |
Suspended substance (mg/L) |
Do not detect |
6 |
Total hardness (mg/L) is (with CaCO
3Meter)
|
<20 |
? |
? |
? |
6, the dense water that membrane separation unit is discharged is for the preparation of coal water slurry, and final fresh water is back to coal water slurry ash water system.
7, when film cleans, adopt the alkali lye of NaOH preparation to carry out on-line cleaning, alkali lye pH value is controlled between 11 ~ 13.
Embodiment 2
As shown in Figure 1, membrane technique of the present invention is processed the method for crushed coal pressure gasifying process spent water, and concrete implementation step is as follows:
1, as follows from the process spent water index of phenol ammonia recovery unit discharge:
CODcr:3500 ~ 4500 mg/l, phenols: 900-1200mg/L, NH3-N:150~250 mg/l, oils: 200 mg/l, temperature: 35 ~ 45 DEG C, pH value: 7.0 ~ 9.5.
2, process spent water is first removed mechanical impurity through mechanical filter and secondary filter, prevents the film of rear system result in blockage or damage.
Described mechanical filter adopts vertical mechanical strainer, and filtrate is selected quartz sand, has unique water distribution uniformity mode, makes strainer reach maximum efficiency, can meet for a long time effluent quality requirement.
It is the filler particles scratching film surface that prevents leakage that described secondary filter adopts the effect of accurate filter, and filtering accuracy is 5 μ m, and filter core is PP cotton or wire-wound filter core.
3, the process spent water after filtration adds alkali adjusting pH value to 9.0, then enters one-level low-pressure membrane (one-level A), is separated into one-level A fresh water and the dense water of one-level A, and the dense water of one-level A enters the concentrated film (one-level B) of one-level, is separated into one-level B fresh water and the dense water of one-level B.Remove most of phenols in sewage by one-level film, the effect that one-level film entrance adds alkali has two, and one is to prevent that sewage from causing dirty blocking up to film, and another is to be more conducive to removing of phenols.
4, one-level A fresh water and one-level B fresh water enter secondary film after merging, and further remove phenols, are separated into the dense water of secondary fresh water and secondary, and secondary concentrate recirculation is to one-level low-pressure membrane entrance.
5, secondary fresh water adds acid for adjusting pH value to 6.0, then enters three grades of film removal of ammonia and nitrogen, is separated into final fresh water and three grades of dense water.The effect of acid adding is for the free ammonia in water is converted into ammonium ion, thereby removes.
One-level low-pressure membrane and one-level concentrate HL8040 film or the ESNA1-K1 film of Hydranautics company product, the AD8040 film of secondary film, three grades of films employing GE products or the SWC film that Hydranautics company produces that film adopts GE company to produce.
Final fresh water index is as follows:
Sequence number |
Project |
Numerical value |
Sequence number |
Project |
Numerical value |
1 |
pH |
6~8 |
7 |
COD(mg/L) |
40 |
2 |
Colourity |
10 |
8 |
NH3-N(mg/L) |
5 |
3 |
Electricity is led (μ s/cm) |
<50 |
9 |
SO
4 2-(mg/L)
|
<20 |
4 |
Turbidity (mg/L) |
Do not detect |
10 |
Na
+(mg/L)
|
<10 |
5 |
Cl
-(mg/L)
|
<10 |
11 |
Suspended substance (mg/L) |
Do not detect |
6 |
Total hardness (mg/L) is (with CaCO
3Meter)
|
<20 |
? |
? |
? |
8, the dense water that membrane separation unit is discharged is for the preparation of coal water slurry, and final fresh water is back to coal water slurry ash water system.
9, when film cleans, adopt the alkali lye of NaOH preparation to carry out on-line cleaning, alkali lye pH value is controlled between 11 ~ 13.
Embodiment 3
As shown in Figure 1, membrane technique of the present invention is processed the method for crushed coal pressure gasifying process spent water, and concrete implementation step is as follows:
1, as follows from the process spent water index of phenol ammonia recovery unit discharge:
CODcr:3500 ~ 4500 mg/l, phenols: 900-1200mg/L, NH3-N:150~250 mg/l, oils: 200 mg/l, temperature: 35 ~ 45 DEG C, pH value: 7.0 ~ 9.5.
2, process spent water is first removed mechanical impurity through mechanical filter and secondary filter, prevents the film of rear system result in blockage or damage.
Described mechanical filter adopts vertical mechanical strainer, and filtrate is selected quartz sand, has unique water distribution uniformity mode, makes strainer reach maximum efficiency, can meet for a long time effluent quality requirement.
It is the filler particles scratching film surface that prevents leakage that described secondary filter adopts the effect of accurate filter, and filtering accuracy is 5 μ m, and filter core is PP cotton or wire-wound filter core.
3, the process spent water after filtration adds alkali adjusting pH value to 10.5, then enters one-level low-pressure membrane (one-level A), is separated into one-level A fresh water and the dense water of one-level A, and the dense water of one-level A enters the concentrated film (one-level B) of one-level, is separated into one-level B fresh water and the dense water of one-level B.Remove most of phenols in sewage by one-level film, the effect that one-level film entrance adds alkali has two, and one is to prevent that sewage from causing dirty blocking up to film, and another is to be more conducive to removing of phenols.
4, one-level A fresh water and one-level B fresh water enter secondary film after merging, and further remove phenols, are separated into the dense water of secondary fresh water and secondary, and secondary concentrate recirculation is to one-level low-pressure membrane entrance.
5, secondary fresh water adds acid for adjusting pH value to 8.0, then enters three grades of film removal of ammonia and nitrogen, is separated into final fresh water and three grades of dense water.The effect of acid adding is for the free ammonia in water is converted into ammonium ion, thereby removes.
One-level low-pressure membrane and one-level concentrate HL8040 film or the ESNA1-K1 film of Hydranautics company product, the AD8040 film of secondary film, three grades of films employing GE products or the SWC film that Hydranautics company produces that film adopts GE company to produce.
Final fresh water index is as follows:
Sequence number |
Project |
Numerical value |
Sequence number |
Project |
Numerical value |
1 |
pH |
6~8 |
7 |
COD(mg/L) |
40 |
2 |
Colourity |
10 |
8 |
NH3-N(mg/L) |
5 |
3 |
Electricity is led (μ s/cm) |
<50 |
9 |
SO
4 2-(mg/L)
|
<20 |
4 |
Turbidity (mg/L) |
Do not detect |
10 |
Na
+(mg/L)
|
<10 |
5 |
Cl
-(mg/L)
|
<10 |
11 |
Suspended substance (mg/L) |
Do not detect |
6 |
Total hardness (mg/L) is (with CaCO
3Meter)
|
<20 |
? |
? |
? |
10, the dense water that membrane separation unit is discharged is for the preparation of coal water slurry, and final fresh water is back to coal water slurry ash water system.
11, when film cleans, adopt the alkali lye of NaOH preparation to carry out on-line cleaning, alkali lye pH value is controlled between 11 ~ 13.