WO1997003928A1 - Process for treating a surplus activated sludge - Google Patents
Process for treating a surplus activated sludge Download PDFInfo
- Publication number
- WO1997003928A1 WO1997003928A1 PCT/RU1996/000032 RU9600032W WO9703928A1 WO 1997003928 A1 WO1997003928 A1 WO 1997003928A1 RU 9600032 W RU9600032 W RU 9600032W WO 9703928 A1 WO9703928 A1 WO 9703928A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- activated sludge
- surplus activated
- treating
- sulfate
- pulp production
- Prior art date
Links
- 238000000034 method Methods 0.000 title claims abstract description 40
- 239000010802 sludge Substances 0.000 title claims abstract description 40
- 230000008569 process Effects 0.000 title claims abstract description 36
- 238000004519 manufacturing process Methods 0.000 claims abstract description 23
- 238000001914 filtration Methods 0.000 claims abstract description 22
- 238000003756 stirring Methods 0.000 claims abstract description 7
- 238000009993 causticizing Methods 0.000 claims abstract description 6
- 230000008719 thickening Effects 0.000 claims description 4
- 239000003153 chemical reaction reagent Substances 0.000 abstract description 10
- 239000002699 waste material Substances 0.000 abstract description 8
- 230000018044 dehydration Effects 0.000 abstract description 5
- 238000006297 dehydration reaction Methods 0.000 abstract description 5
- 230000009467 reduction Effects 0.000 abstract description 3
- 239000010842 industrial wastewater Substances 0.000 abstract description 2
- 239000000463 material Substances 0.000 abstract description 2
- 239000010841 municipal wastewater Substances 0.000 abstract description 2
- 238000000746 purification Methods 0.000 abstract description 2
- VTYYLEPIZMXCLO-UHFFFAOYSA-L Calcium carbonate Chemical compound [Ca+2].[O-]C([O-])=O VTYYLEPIZMXCLO-UHFFFAOYSA-L 0.000 description 8
- 239000002245 particle Substances 0.000 description 5
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 5
- 229910000019 calcium carbonate Inorganic materials 0.000 description 4
- 239000002244 precipitate Substances 0.000 description 4
- 238000001035 drying Methods 0.000 description 3
- 239000000203 mixture Substances 0.000 description 3
- 150000002894 organic compounds Chemical class 0.000 description 3
- 230000008929 regeneration Effects 0.000 description 3
- 238000011069 regeneration method Methods 0.000 description 3
- 239000007787 solid Substances 0.000 description 3
- 239000000126 substance Substances 0.000 description 3
- CDBYLPFSWZWCQE-UHFFFAOYSA-L Sodium Carbonate Chemical compound [Na+].[Na+].[O-]C([O-])=O CDBYLPFSWZWCQE-UHFFFAOYSA-L 0.000 description 2
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 description 2
- 239000012670 alkaline solution Substances 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- BRPQOXSCLDDYGP-UHFFFAOYSA-N calcium oxide Chemical compound [O-2].[Ca+2] BRPQOXSCLDDYGP-UHFFFAOYSA-N 0.000 description 2
- 239000000292 calcium oxide Substances 0.000 description 2
- ODINCKMPIJJUCX-UHFFFAOYSA-N calcium oxide Inorganic materials [Ca]=O ODINCKMPIJJUCX-UHFFFAOYSA-N 0.000 description 2
- 239000013505 freshwater Substances 0.000 description 2
- 230000004927 fusion Effects 0.000 description 2
- 239000000047 product Substances 0.000 description 2
- 239000000725 suspension Substances 0.000 description 2
- HRPVXLWXLXDGHG-UHFFFAOYSA-N Acrylamide Chemical compound NC(=O)C=C HRPVXLWXLXDGHG-UHFFFAOYSA-N 0.000 description 1
- 235000008733 Citrus aurantifolia Nutrition 0.000 description 1
- 229910021578 Iron(III) chloride Inorganic materials 0.000 description 1
- CERQOIWHTDAKMF-UHFFFAOYSA-N Methacrylic acid Chemical class CC(=C)C(O)=O CERQOIWHTDAKMF-UHFFFAOYSA-N 0.000 description 1
- 235000011941 Tilia x europaea Nutrition 0.000 description 1
- 229940117913 acrylamide Drugs 0.000 description 1
- 239000003513 alkali Substances 0.000 description 1
- 238000005904 alkaline hydrolysis reaction Methods 0.000 description 1
- 150000001413 amino acids Chemical class 0.000 description 1
- 150000001414 amino alcohols Chemical class 0.000 description 1
- 150000003863 ammonium salts Chemical class 0.000 description 1
- 239000008346 aqueous phase Substances 0.000 description 1
- 239000007864 aqueous solution Substances 0.000 description 1
- 239000007900 aqueous suspension Substances 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 229920001577 copolymer Polymers 0.000 description 1
- 238000004090 dissolution Methods 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 230000008020 evaporation Effects 0.000 description 1
- 239000004744 fabric Substances 0.000 description 1
- -1 for example chalk Inorganic materials 0.000 description 1
- 229910052602 gypsum Inorganic materials 0.000 description 1
- 239000010440 gypsum Substances 0.000 description 1
- 150000002484 inorganic compounds Chemical class 0.000 description 1
- 229910010272 inorganic material Inorganic materials 0.000 description 1
- 229910052500 inorganic mineral Inorganic materials 0.000 description 1
- RBTARNINKXHZNM-UHFFFAOYSA-K iron trichloride Chemical compound Cl[Fe](Cl)Cl RBTARNINKXHZNM-UHFFFAOYSA-K 0.000 description 1
- 239000004571 lime Substances 0.000 description 1
- 239000008267 milk Substances 0.000 description 1
- 210000004080 milk Anatomy 0.000 description 1
- 235000013336 milk Nutrition 0.000 description 1
- 239000011707 mineral Substances 0.000 description 1
- 230000002035 prolonged effect Effects 0.000 description 1
- 102000004169 proteins and genes Human genes 0.000 description 1
- 108090000623 proteins and genes Proteins 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 239000010865 sewage Substances 0.000 description 1
- 229910000029 sodium carbonate Inorganic materials 0.000 description 1
- 239000007790 solid phase Substances 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 238000005406 washing Methods 0.000 description 1
Classifications
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
- D21C11/00—Regeneration of pulp liquors or effluent waste waters
- D21C11/0064—Aspects concerning the production and the treatment of green and white liquors, e.g. causticizing green liquor
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F11/00—Treatment of sludge; Devices therefor
- C02F11/12—Treatment of sludge; Devices therefor by de-watering, drying or thickening
- C02F11/121—Treatment of sludge; Devices therefor by de-watering, drying or thickening by mechanical de-watering
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F11/00—Treatment of sludge; Devices therefor
- C02F11/12—Treatment of sludge; Devices therefor by de-watering, drying or thickening
- C02F11/14—Treatment of sludge; Devices therefor by de-watering, drying or thickening with addition of chemical agents
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F11/00—Treatment of sludge; Devices therefor
- C02F11/12—Treatment of sludge; Devices therefor by de-watering, drying or thickening
- C02F11/14—Treatment of sludge; Devices therefor by de-watering, drying or thickening with addition of chemical agents
- C02F11/143—Treatment of sludge; Devices therefor by de-watering, drying or thickening with addition of chemical agents using inorganic substances
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F11/00—Treatment of sludge; Devices therefor
- C02F11/12—Treatment of sludge; Devices therefor by de-watering, drying or thickening
- C02F11/14—Treatment of sludge; Devices therefor by de-watering, drying or thickening with addition of chemical agents
- C02F11/143—Treatment of sludge; Devices therefor by de-watering, drying or thickening with addition of chemical agents using inorganic substances
- C02F11/145—Treatment of sludge; Devices therefor by de-watering, drying or thickening with addition of chemical agents using inorganic substances using calcium compounds
Definitions
- the present invention relates to a process for treating settlings formed during the biological purification of municipal and industrial waste water and may be used in various fields of industry, in particular in paper and pulp production.
- the main disadvantage of the known process consists an low effectiveness and high duration of a process for dehydrating the settlings by filtering, which is caused by an unfavorable structure of said settlings that firmly retain water and have a high specific filtration resist-ance.
- the known process requires the use of expensive alkaline reagents /see Y ⁇ . N. Nelepin, "Sulfate Pulp Production”, “Lesnaya Promyshlennost", Moscow, 1990, p. 531/.
- the present invention is made in order to solve the above problems included in the prior arts, and an object of this invention is to provide a new process for treating a surplus activated sludge enabling intensification of the process for dehydrating the settlings by filtering, avoiding the use of expensive chemical reagents, a complete utilization of the process products so obtained (a clarified alkaline hydrolyzate and an ash residue) as well as utilization of the sulfate-pulp production waste with minimal costs.
- the above technical result is achieved in accordance with the present invention by treating a pre-thickened surplus activated sludge with white slime obtained at the stage of causticizing green liquor in the process of the sulfate-pulp production, with stirring and in a volume ratio of white slime : surplus activated sludge equal to 1 : 5 - 10 followed by dehydration by means of filtering, drying and burning down of the dehydrated settlings.
- the present process differs from the known one in that it provides for the treatment of the pre-dehydrated surplus activated sludge with white slime obtained at the stage of causticizing green liquor in the process of the sulfate-pulp production, with stirring and in a volume ratio of white slime : surplus activated sludge equal to 1 : 5 - 10.
- White slime used in the present process for treating the surplus activated sludge is a sulfate-pulp production waste being a black suspension with a density of 1.25 - 1.35 Kg/cub. dm and having the following chemical composition, % wt.:
- Using white slime in accordance with the present process allows solution of two problems at once: on the one hand, to intensify and lower the price of the process for treating the surplus activated sludge and, on the other hand, to significantly simplify and lower the price of the process for utilizing white slime.
- a process for treating the surplus activated sludge thickened when p-resettling the precipitate, by means of white slime containing alkali residues is accompanied with practically a complete alkaline hydrolysis of the bioorganic part of the sludge (constituting not less than 83 % wt. on dry residue) with the formation of salts of amino acids, amino alcohols and a number of protein derivatives.
- calcium carbonate constituting the major contents of white slime is uniformly distributed, when stirred thoroughly, among undissolved large fibres and solid particles present in the surplus activated sludge in the amount up to 17 % wt. on dry basis.
- the present process is carried out. m the following manner.
- the surplus activated sludge is subjected to pre-thickening in a radial or vertical pond. Most preferably, thickening is carried out up to the surplus activated sludge concentration of 18 - 40 g/1.
- the surplus activated sludge is fed to a mixer where it is treated with white slime, while stirring.
- White slime is used in a volume ratio to the surplus activated sludge equal to 1 : 5 - 10 which allows achievement of a maximal efficiency of post-filtering.
- a filtering rate reduces significantly. It is not to the purpose of technology to use white slime in the amounts exceeding the claimed ratio.
- stirring is carried out at a temperature of between 75 and 104 C. It is also possible to use lower temperatures, up to room temperature, but in this case a process for treating becomes more prolonged.
- the treatment is carried out to a complete dissolution of a bioorganic part of the surplus activated sludge. Then, a mixture so obtained which contains an alkaline hydrolyzate, undissolved fibres and solid particles present in the surplus activated sludge, as well as calcium carbonate uniformly distributed among the particles of sludge settlings as a result of stirring, are fed to a vacuum filter or a pressure filter and subjected to dehydration.
- a clarified alkaline hydrolyzate obtained upon filtration may be used, without a subsequent treatment, in the manufacturing cycle of the sulfate-pulp production at the stage of reagent regeneration.
- a dehydrated precipitate formed on a filter surface is readily removed from the filter surface, thereupon it is subjected to heat drying in drier drums and fed to burn down in an utilization plant furnace.
- An ash residue comprising calcium oxide is used in the manufacturing cycle of the sulfate-pulp production at the stage of a green liquor causticizing.
- a concentration of 80 g/l, 0.75 1 of a white slime suspension is added and thoroughly stirred for 15 minutes at 95 C.
- a mixture so obtained is fed to a vacuum filter and subjected to dehydration of the settlings.
- a filtration rate is determined to be 40 I/sq. m/min.
- a clarified alkaline hydrolyzate is fed to be used in the manufacturing cycle of the sulfate-pulp production.
- a dehydrated precipitate formed on a filter surface is removed and subjected to heat drying at 850 C, thereupon it is burned down.
- An ash residue obtained is fed to the stage of a green liquor causticizing.
- the present process for treating the surplus activated sludge allows intensification of the filtration process, avoiding the use of expensive chemical reagents (at. the expense of using waste of the sulfate-pulp production), a complete utilization of products obtained when treating the sludge (an ash residue and a clarified alkaline hydrolyzate) as well as utilization of the sulfate-pulp production waste, that is white slime, with simplification of the production procedures and techniques and significant reduction of material costs.
- a filtration rate in accordance with the known process is 4 l/sq. m/min. Besides, reduction in a dehydration process time according to the present process results in the decrease of energy consumed to realize thereof.
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Environmental & Geological Engineering (AREA)
- Life Sciences & Earth Sciences (AREA)
- Hydrology & Water Resources (AREA)
- Water Supply & Treatment (AREA)
- Organic Chemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Mechanical Engineering (AREA)
- Paper (AREA)
- Treatment Of Sludge (AREA)
- Separation Of Suspended Particles By Flocculating Agents (AREA)
Abstract
The present invention relates to a process for treating settlings formed during the biological purification of municipal and industrial waste water and may be used in various fields of industry, in particular in paper and pulp production. A pre-thickened surplus activated sludge is subjected to treatment with white slime obtained at the state of causticizing green liquour in the sulfate-pulp production, while stirring. White slime is used in a volume ratio to the surplus activated sludge equal to 1 : 5 - 10. Thereupon, the sludge so treated is subjected to dehydration by filtering, preferably at a temperature of between 75 and 104 °C. The dehydrated settlings are dried and burned down. An ash residue so obtained as well as a clarified alkaline hydrolyzate are used in the manufacturing process of the sulfate-pulp production. The present process for treating the surplus activated sludge allows intensification of the filtration process, avoiding the use of expensive chemical reagents, a complete utilization of products obtained when treating the sludge as well as utilization of the sulfate-pulp production waste, that is white slime, with simplification of the production procedures and techniques and significant reduction of material costs.
Description
PROCESS FOR TREATING A SURPLUS ACTIVATED SLUDGE
TECHNICAL FIELD
The present invention relates to a process for treating settlings formed during the biological purification of municipal and industrial waste water and may be used in various fields of industry, in particular in paper and pulp production.
BACKGROUND ART
There have been known processes for treating a surplus activated sludge with special reagents followed by its separation into water and thickened settlings by means of filtering or settling. In most cases, an aqueous solution of ferric chloride and lime milk /see O. I. Yakovleva et al., "Sewage Treatment", "Lesnaya Promyshlennost", Moscow, 1975, pp. 40 - 43/, as well as various ammonium salts /see US Patent No. 4240904, Int. Cl. CO2F 11/14, 1980/ and organic compounds /see USSR Inventor's Certificate No. 827424, Int. CI. CO2F 11/14, 1981/ are used for this purpose.
There have been also known processes for treating a surplus activated sludge by separating into water and thickened settlings by means of filtering and using auxiliary filtering substances such as, for example inorganic compounds, for example chalk, gypsum /as in the above mentioned USSR Inventor"s Certificate No. 827424/, or high-molecular organic compounds, for example copolymer of acr-ylamide with methacrylic acid derivatives /see GE Patent Specification No. 1466185, Int. 01. C02C 3/00, 1977/.
Of the major drawbacks of the aforementioned processes is the use of expensive chemical reagents, practically in the
complete absence of their regeneration.
The closest prior art has been described in a process for treating a surplus activated sludge, comprising the steps of presettling followed by filtering, avoiding the step of treatment by reagents. Settlings formed as a result of dehydrating the surplus activated sludge are treated just on a filtering cloth with an aqueous alkaline solution or white sulfate liquor. In this case, a highly concentrated alkaline solution of the surplus activated sludge is obtained folowed by its evaporation and sending to burn down /see USSR Inventor's Certificate No. 1038237. Int. Cl. CO2F 11/14, 1933/.
The main disadvantage of the known process consists an low effectiveness and high duration of a process for dehydrating the settlings by filtering, which is caused by an unfavorable structure of said settlings that firmly retain water and have a high specific filtration resist-ance. Moreover, the known process requires the use of expensive alkaline reagents /see Yυ. N. Nelepin, "Sulfate Pulp Production", "Lesnaya Promyshlennost", Moscow, 1990, p. 531/.
SUMMARY OF THE PRESENT INVENTION
The present invention is made in order to solve the above problems included in the prior arts, and an object of this invention is to provide a new process for treating a surplus activated sludge enabling intensification of the process for dehydrating the settlings by filtering, avoiding the use of expensive chemical reagents, a complete utilization of the process products so obtained (a clarified alkaline hydrolyzate and an ash residue) as well as utilization of the sulfate-pulp production waste with minimal costs.
The above technical result is achieved in accordance with the present invention by treating a pre-thickened surplus activated sludge with white slime obtained at the stage of
causticizing green liquor in the process of the sulfate-pulp production, with stirring and in a volume ratio of white slime : surplus activated sludge equal to 1 : 5 - 10 followed by dehydration by means of filtering, drying and burning down of the dehydrated settlings.
The present process differs from the known one in that it provides for the treatment of the pre-dehydrated surplus activated sludge with white slime obtained at the stage of causticizing green liquor in the process of the sulfate-pulp production, with stirring and in a volume ratio of white slime : surplus activated sludge equal to 1 : 5 - 10.
White slime used in the present process for treating the surplus activated sludge is a sulfate-pulp production waste being a black suspension with a density of 1.25 - 1.35 Kg/cub. dm and having the following chemical composition, % wt.:
It is common knowledge that upon regeneration of a waste black liquor during the sulfate-pulp process, a fusion cake (a mineral part of the waste black liquor) is formed with sodium carbonate being its main component. Then, the fusion cake is dissolved and green liquor formed therewith is subjected to causticization by adding calcium oxide to obtain a strong white liquor and a calcium carbonate precipitate, that is white slime. Usually, a subsequent utilization of white slime requires its repeated washing with fresh water using special chemical reagents /see USSR Inventor's Certificate No. 827424, C 02 F 11/14, 1981/. The necessity of using fresh water and expensive organic compounds significantly complicates the
process and rises its cost.
Using white slime in accordance with the present process allows solution of two problems at once: on the one hand, to intensify and lower the price of the process for treating the surplus activated sludge and, on the other hand, to significantly simplify and lower the price of the process for utilizing white slime.
A process for treating the surplus activated sludge thickened when p-resettling the precipitate, by means of white slime containing alkali residues is accompanied with practically a complete alkaline hydrolysis of the bioorganic part of the sludge (constituting not less than 83 % wt. on dry residue) with the formation of salts of amino acids, amino alcohols and a number of protein derivatives. In turn, calcium carbonate constituting the major contents of white slime, is uniformly distributed, when stirred thoroughly, among undissolved large fibres and solid particles present in the surplus activated sludge in the amount up to 17 % wt. on dry basis. This results in the change of an unfavorable structure of the surplus activated sludge settlings which, under nor-mal conditions (that is, in the absence of treatment with special reagents), firmly retain water and have a high specific filtration resistance. Solid particles and large fibres of the surplus activated sludge join with particles of calcium carbonate and lose water with the formation of a solid phase which is readily separated from an aqueous phase by filtration. Thus, in accordance with the present process, white slime being the sulfate-pulp production waste, on the one hand, replaces an expensive alkaline agent and, on the other hand, performs functions of an auxiliary filtering substance.
The present process is carried out. m the following manner.
The surplus activated sludge is subjected to
pre-thickening in a radial or vertical pond. Most preferably, thickening is carried out up to the surplus activated sludge concentration of 18 - 40 g/1. Upon thickening, the surplus activated sludge is fed to a mixer where it is treated with white slime, while stirring. White slime is used in a volume ratio to the surplus activated sludge equal to 1 : 5 - 10 which allows achievement of a maximal efficiency of post-filtering. When treating the sludge with white slime taken in the amount less than that mentioned above, a filtering rate reduces significantly. It is not to the purpose of technology to use white slime in the amounts exceeding the claimed ratio. Most preferably, stirring is carried out at a temperature of between 75 and 104 C. It is also possible to use lower temperatures, up to room temperature, but in this case a process for treating becomes more prolonged. The treatment is carried out to a complete dissolution of a bioorganic part of the surplus activated sludge. Then, a mixture so obtained which contains an alkaline hydrolyzate, undissolved fibres and solid particles present in the surplus activated sludge, as well as calcium carbonate uniformly distributed among the particles of sludge settlings as a result of stirring, are fed to a vacuum filter or a pressure filter and subjected to dehydration. A clarified alkaline hydrolyzate obtained upon filtration may be used, without a subsequent treatment, in the manufacturing cycle of the sulfate-pulp production at the stage of reagent regeneration. A dehydrated precipitate formed on a filter surface is readily removed from the filter surface, thereupon it is subjected to heat drying in drier drums and fed to burn down in an utilization plant furnace. An ash residue comprising calcium oxide is used in the manufacturing cycle of the sulfate-pulp production at the stage of a green liquor causticizing.
BEST MODE FOR CARRYING OUT THE INVENTION
To 5 I of an aqueous suspension of the surplus activated sludge having, after settling in a radial pond, a concentration of 80 g/l, 0.75 1 of a white slime suspension is added and thoroughly stirred for 15 minutes at 95 C. A mixture so obtained is fed to a vacuum filter and subjected to dehydration of the settlings. In this case, a filtration rate is determined to be 40 I/sq. m/min. A clarified alkaline hydrolyzate is fed to be used in the manufacturing cycle of the sulfate-pulp production. A dehydrated precipitate formed on a filter surface is removed and subjected to heat drying at 850 C, thereupon it is burned down. An ash residue obtained is fed to the stage of a green liquor causticizing.
INDUSTRIAL APPLILIABILITY
The present process for treating the surplus activated sludge allows intensification of the filtration process, avoiding the use of expensive chemical reagents (at. the expense of using waste of the sulfate-pulp production), a complete utilization of products obtained when treating the sludge (an ash residue and a clarified alkaline hydrolyzate) as well as utilization of the sulfate-pulp production waste, that is white slime, with simplification of the production procedures and techniques and significant reduction of material costs. For the purpose of comparison, a filtration rate in accordance with the known process is 4 l/sq. m/min. Besides, reduction in a dehydration process time according to the present process results in the decrease of energy consumed to realize thereof.
Claims
1. A process for treating a surplus activated sludge in which the surplus activated sludge is pre-thickened, dehydrated by filtration and the dehydrated settlings are dried and burned down, wherein prior to the stage of filtration, a pre-thickened surplus activated sludge is treated with white slime obtained at the stage of causticizing green liquor in the process of the sulfate-pulp production, with stirring and in a volume ratio of white slime : surplus activated sludge equal to 1 : 5 - 10.
2. A process of claim 1 wherein said thickening is carried out to the surplus activated sludge concentration equal to 13 - 40 g/1.
3. A process of claim 1 or 2 wherein said white slime treatment is carried out at a temperature of between 75 and 104 C.
Priority Applications (6)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9506587A JPH11510090A (en) | 1995-07-18 | 1996-02-12 | Excess activated sludge treatment method |
| AU46802/96A AU4680296A (en) | 1995-07-18 | 1996-02-12 | Process for treating a surplus activated sludge |
| BR9609736-1A BR9609736A (en) | 1995-07-18 | 1996-02-12 | Process for handling an overrun |
| EP96902522A EP0842125A1 (en) | 1995-07-18 | 1996-02-12 | Process for treating a surplus activated sludge |
| NO980210A NO980210D0 (en) | 1995-07-18 | 1998-01-16 | Process for treating activated sludge excess |
| FI980091A FI980091A0 (en) | 1995-07-18 | 1998-01-16 | Procedure for the treatment of excess sludge |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| RU9595112218A RU2079454C1 (en) | 1995-07-18 | 1995-07-18 | Method of processing excessive activated sludge |
| RU95112218 | 1995-07-18 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| WO1997003928A1 true WO1997003928A1 (en) | 1997-02-06 |
Family
ID=20170155
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| PCT/RU1996/000032 WO1997003928A1 (en) | 1995-07-18 | 1996-02-12 | Process for treating a surplus activated sludge |
Country Status (11)
| Country | Link |
|---|---|
| EP (1) | EP0842125A1 (en) |
| JP (1) | JPH11510090A (en) |
| KR (1) | KR19990028251A (en) |
| CN (1) | CN1196033A (en) |
| AU (1) | AU4680296A (en) |
| BR (1) | BR9609736A (en) |
| CA (1) | CA2224683A1 (en) |
| FI (1) | FI980091A0 (en) |
| NO (1) | NO980210D0 (en) |
| RU (1) | RU2079454C1 (en) |
| WO (1) | WO1997003928A1 (en) |
Families Citing this family (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| SE9803384L (en) * | 1998-03-02 | 1999-09-03 | Kemira Kemi Ab | Process for treating process water |
| RU2167969C1 (en) * | 2000-05-10 | 2001-05-27 | Грудинин Владимир Павлович | Method of washing lime sludge of strong white lye |
| CN1295399C (en) * | 2003-12-01 | 2007-01-17 | 中国农业科学院土壤肥料研究所 | Technology of repairing rock dome using mixed polymer of daily sludge and waste plastics |
| WO2013066225A1 (en) * | 2011-11-04 | 2013-05-10 | Metso Paper Sweden Ab | Method for the causticizing process for producing white liquor |
| CN102491618A (en) * | 2011-11-29 | 2012-06-13 | 曾秀仪 | Depth dehydration method for residual sludge |
| CN106396308B (en) * | 2016-10-27 | 2019-12-31 | 环境保护部华南环境科学研究所 | Recycling method of residual activated sludge |
| CN109279758B (en) * | 2018-11-21 | 2021-08-10 | 湖南骏泰新材料科技有限责任公司 | Efficient green mud washing method |
| CN110424179B (en) * | 2019-08-26 | 2021-09-21 | 华南理工大学 | Method for modifying solid waste after incineration of papermaking sludge to be used as papermaking filler |
| CN112726252B (en) * | 2020-11-30 | 2022-11-25 | 山东华泰纸业股份有限公司 | Comprehensive utilization method of waste residues in paper mill |
| CN112796144A (en) * | 2020-12-28 | 2021-05-14 | 山东泗水金立得纸业有限公司 | Method for recycling kaolin from sludge of carbon-free copy paper production line |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1466185A (en) * | 1973-03-07 | 1977-03-02 | Andco Inc | Dewatering of slimes |
| US4030968A (en) * | 1975-12-22 | 1977-06-21 | Consolidated-Bathurst Limited | Disposal of paper pulp mill sludge |
| US4240904A (en) * | 1977-06-27 | 1980-12-23 | Stamicarbon, B.V. | Process for biological purification of waste water |
| GB2066304A (en) * | 1979-11-20 | 1981-07-08 | Vn Proizv Ob Celljuloszno | Method for recovery of wastewater residues |
| SU1038287A1 (en) * | 1979-11-20 | 1983-08-30 | Всесоюзное научно-производственное объединение целлюлозно-бумажной промышленности | Method of treating excessive active slurry |
-
1995
- 1995-07-18 RU RU9595112218A patent/RU2079454C1/en active
-
1996
- 1996-02-12 EP EP96902522A patent/EP0842125A1/en not_active Withdrawn
- 1996-02-12 WO PCT/RU1996/000032 patent/WO1997003928A1/en active IP Right Grant
- 1996-02-12 CA CA002224683A patent/CA2224683A1/en not_active Abandoned
- 1996-02-12 JP JP9506587A patent/JPH11510090A/en active Pending
- 1996-02-12 KR KR1019970709562A patent/KR19990028251A/en not_active Abandoned
- 1996-02-12 AU AU46802/96A patent/AU4680296A/en not_active Abandoned
- 1996-02-12 BR BR9609736-1A patent/BR9609736A/en not_active Application Discontinuation
- 1996-02-12 CN CN96196796A patent/CN1196033A/en active Pending
-
1998
- 1998-01-16 FI FI980091A patent/FI980091A0/en unknown
- 1998-01-16 NO NO980210A patent/NO980210D0/en unknown
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1466185A (en) * | 1973-03-07 | 1977-03-02 | Andco Inc | Dewatering of slimes |
| US4030968A (en) * | 1975-12-22 | 1977-06-21 | Consolidated-Bathurst Limited | Disposal of paper pulp mill sludge |
| US4240904A (en) * | 1977-06-27 | 1980-12-23 | Stamicarbon, B.V. | Process for biological purification of waste water |
| GB2066304A (en) * | 1979-11-20 | 1981-07-08 | Vn Proizv Ob Celljuloszno | Method for recovery of wastewater residues |
| SU1038287A1 (en) * | 1979-11-20 | 1983-08-30 | Всесоюзное научно-производственное объединение целлюлозно-бумажной промышленности | Method of treating excessive active slurry |
Also Published As
| Publication number | Publication date |
|---|---|
| KR19990028251A (en) | 1999-04-15 |
| FI980091L (en) | 1998-01-16 |
| NO980210L (en) | 1998-01-16 |
| AU4680296A (en) | 1997-02-18 |
| NO980210D0 (en) | 1998-01-16 |
| FI980091A0 (en) | 1998-01-16 |
| CN1196033A (en) | 1998-10-14 |
| CA2224683A1 (en) | 1997-02-06 |
| RU2079454C1 (en) | 1997-05-20 |
| EP0842125A1 (en) | 1998-05-20 |
| BR9609736A (en) | 1999-12-21 |
| JPH11510090A (en) | 1999-09-07 |
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