CA2005029C - Method for reducing the buildup of slime and film in plant - Google Patents
Method for reducing the buildup of slime and film in plantInfo
- Publication number
- CA2005029C CA2005029C CA002005029A CA2005029A CA2005029C CA 2005029 C CA2005029 C CA 2005029C CA 002005029 A CA002005029 A CA 002005029A CA 2005029 A CA2005029 A CA 2005029A CA 2005029 C CA2005029 C CA 2005029C
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- bacteria
- added
- microorganisms
- circulating water
- toc
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Classifications
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F3/00—Biological treatment of water, waste water, or sewage
- C02F3/34—Biological treatment of water, waste water, or sewage characterised by the microorganisms used
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/50—Treatment of water, waste water, or sewage by addition or application of a germicide or by oligodynamic treatment
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F5/00—Softening water; Preventing scale; Adding scale preventatives or scale removers to water, e.g. adding sequestering agents
- C02F5/08—Treatment of water with complexing chemicals or other solubilising agents for softening, scale prevention or scale removal, e.g. adding sequestering agents
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F5/00—Softening water; Preventing scale; Adding scale preventatives or scale removers to water, e.g. adding sequestering agents
- C02F5/08—Treatment of water with complexing chemicals or other solubilising agents for softening, scale prevention or scale removal, e.g. adding sequestering agents
- C02F5/10—Treatment of water with complexing chemicals or other solubilising agents for softening, scale prevention or scale removal, e.g. adding sequestering agents using organic substances
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F2103/00—Nature of the water, waste water, sewage or sludge to be treated
- C02F2103/02—Non-contaminated water, e.g. for industrial water supply
- C02F2103/023—Water in cooling circuits
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- Chemical & Material Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Hydrology & Water Resources (AREA)
- Engineering & Computer Science (AREA)
- Environmental & Geological Engineering (AREA)
- Water Supply & Treatment (AREA)
- Organic Chemistry (AREA)
- Microbiology (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (AREA)
- Biodiversity & Conservation Biology (AREA)
- Apparatus Associated With Microorganisms And Enzymes (AREA)
- Micro-Organisms Or Cultivation Processes Thereof (AREA)
- Paper (AREA)
- Agricultural Chemicals And Associated Chemicals (AREA)
- Fertilizers (AREA)
- Breeding Of Plants And Reproduction By Means Of Culturing (AREA)
- Purification Treatments By Anaerobic Or Anaerobic And Aerobic Bacteria Or Animals (AREA)
- Peptides Or Proteins (AREA)
- Protection Of Plants (AREA)
- Formation Of Insulating Films (AREA)
- Hydroponics (AREA)
- Preparation Of Compounds By Using Micro-Organisms (AREA)
- Measuring Or Testing Involving Enzymes Or Micro-Organisms (AREA)
- Eye Examination Apparatus (AREA)
- Studio Devices (AREA)
- Advance Control (AREA)
Abstract
In order to reduce the buildup of slime and film in plant which circulates water, microorganisms are added to the circulating water.
Description
A method for reducing the buildup of slime and film in plant The present invention relates to a method for reducing the buildup of slime and film in plant that circulates water.
It is also based on a system for carrying out this method and applications of this method.
Water circulation, in particular the increasingly used closed circulation of the white water on paper machines and cooling water circulation, always involves the problem that and/or film builds up on solid surfaces and in the liquid phase (cf. "Vortrage anla(3lich des 5. PTS-WAF-Lehrgangs, Fortbildungskurs zur Wasser- and Abwasseranalytik, Kontrolle des Einsatzes von mikrobioziden finder Papiererzeugung". ("Lectures in the Fifth PTS-WAF
Course, Further Education on Water and Waste Water Anlysis, Control of the Use of Microbiocides in Paper Production"), organized by the "Papiertechnische Stiftung," Munich, and Hans-Dietrich Held "Kuhlwasser" ("Cooling water") , Vulkan-Verlag Dr. W. Claussen, Essen, 1977, p. 70 to 73).
In the closed circulation of the white water increasingly used for paper machines, microorganisms find very good growth conditions due to the high organic and inorganic nutrient offer present in the white water, and a favourable environment, i.e. a high temperature, a pH value close to the neutral point and a supply of oxygen. Since many of the microorganism are not present in the circulating water as free organisms but settle on the fibrous, filling and fine material and the surfaces of the machine parts, such as pipes, vessels and pumps, there is an undesirable buildup of slime and film. When the slime or film is detached from the surfaces this often leads to the formation of lumps and thus possibly to holes in the paper web. This weakens the paper web, i.e. cause it to tear, thereby resulting in machine standstills. In order to prevent this buildup of slime and film it is known to add biocides, lignosulfonates or enzymes to the white water.
,~~
The use of biocides suppresses the growth of the microorganisms and partly damages them. However, the use of biocides is increasingly criticized. The greater the amount of biocide is, the more damage is done to the environment to which the white water is fed when the circulation is emptied.
Since microorganisms tend to become resistant to biocides it is also necessary to change the biocide substances frequently and/or increase their amount. This means a considerable increase in pollution or considerable costs, e.g. for a following adapted clarification plant or a drainage ditch.
Lignosulfonates are used as so-called "complexers"
which prevent the microorganisms from taking in food under certain conditions. Sometimes a biocide must also be used with the lignosulfonate, but in a much smaller amount then if used alone (cf. German patent no. 34 47 686). The problems of biocides thus continue to exist in a milder form.
Enzymes are added to the white water circulation in order to convert the high molecular polymers, which promote the build up of slime and film, into low molecular products which are uncritical for the buildup of slime and film. This method is environmentally safe but has not proved useful in large scale application, presumably because it only allows for a brief reduction of viscosity, while the hydrolysis or other low molecular products formed by the enzymes may even be preferred food for the slime forming microorganism.
Cooling water circulation involves the problem that leaks or points of contact with the circulating product stream, such as the condensation of gases in the cooling circulation which arise during vaporization processes in the circulating product stream, cause organic impurities to pass into the circulating water in most cases. This again lead to the growth of microorganism. Together with the organic and inorganic impurities, these microorganism chiefly form deposits on the surfaces of the heat exchanges, thereby drastically reducing the heat transmission. This necessitates frequent and expensive cleaning of the heat exchangers to maintain the necessary removal of heat for the particular process. In this case, too, biocides are mainly used to reduce the buildup of slime and film on the ~,a.., , ...
~;0~35(~~9 heat exchanger surfaces.
The invention is therefore based on the problem of finding an environmentally safe method for plant with water circulation which reduces the buildup of slime and film in the water circu-lation, thereby reducing the stop periods of the plant.
This problem is solved by a method of the type stated at the outset whose characterizing feature is that microorganisms are added to the circulating water.
Surprisingly enough, when the inventive method is carried out and microorganisms are selectively added to the circulating water in accordance with its organic load, there is a clear reduction in the buildup of slime and film on solid surfaces and in the liquid phase, although the addition of microorgan-isms constitutes an increased organic contamination of the cir-culating water.
The inventive method presents an environmentally safe way of treating the most diverse types of circulating water in such a way as to largely reduce the buildup of slime and film and shorten the stop periods of the plant.
Microorganisms suitable for the inventive method have proved to be in particular bacteria, mainly bacteria of the following taxonomic groups: Aeromonas/Vibrio, Acinetobacter, Alcaligenes, Enterobacteria, Pseudomonas, Bacillus, Lactobacil-lus, Micrococcus, Staphylococcus and Streptococcus, in particu-lar Aeromonas hydrophila, Acinetobacter calcoacetica, Alcalige-nes eutrophus; Escherichia coli; Nitrosomonas, Nitrobacter, Bacillus megaterium, B. macerans, B. polymyra, B. subtilis, B.
stearothermophilus, B. coagulans, B. circulans, B. cereus, B.
pasteurii; Chromatium; Pseudomonas arvilla, P. putida, P.
stutzeri, P. fluorescens, P. denitrificans, P. aeruginosa; Zoo-gloea; Zymomonas; Leuconostoc; Proteus vulgaris; Sporosarcina ureae; Rhodopseudomonas; Nocardia; Mycobacterium; Flavobacte-rium; Agrobacterium; Cytophaga; Sporocytophaga; Streptomyces;
Micromonospora; Clostridium pectinovorum, C. felsineum; Azoto-bacter: Streptococcus; Cellulomonas; Azomonas; Rhizobium; Thio-bacillus, Thiothrix, Streptobacillus, Spaerothilus, Enterobac-ter aerogenes; Serratia; Propionibacterium; Micrococcus; Ar-throbacter, Corynebacterium, Brevibacterium; Photobacterium;
Xanthomonas, Chromobacterium, Vibrio, Acetotbacter, Lactobacillus. In the following, bacteria will therefore be primarily referred to.
However, other microorganisms can also be used in the inventive method, such as fungi, such a fungi of the groups Myxomycetes, Phycomycetes, Ascomycetes, Basidiomycetes, Deuteromycetes, in particular Acrasiales, Asperigillus niger, A. Oryzae, A. wentii; Candida lipolytica, tropicalis;
Saccharomyces; Chaetomium; Cryptococcus.
One can also use mixtures of bacteria or of fungi or mixtures of bacteria with fungi.
The bacteria use according to the invention are nonsessile bacteria, i.e. microorganisms or bacteria are selected which show no, or only little, tendency to settle on surfaces compared to the microorganism or bacteria forming slime and film in the plant.
The tendency of the added microorganisms or bacteria to settle on surfaces can be further reduced according to the invention by adding tensides to the circulating water. A
suitable tenside has in particular proved to be a tenside called "Konsan" available from KW Kalos & Wiechmann GmbH, Hude.
According to the inventive method the bacteria are added in a relatively large quantity. Furthermore, they are not used in lumps, flakes or colonies but preferably as single bacteria. Due to their large quantity and their single form the bacteria have a very large total surface, so that they lead to strong absorption or intake of the nutrients existing in the circulation. This results in a competition for the food present in the circulating water, which is won by the added nonsessile bacteria, due to their high food intake, and lost by the slime and film forming microorganisms.
In order to allow the bacteria to be added to the circulating water in an optimal single form, the invention preferably assume dry bacteria or mixed cultures or dry bacteria which are stirred by stirring means, well known in the art, into a predetermined volume, whereby after an activation period of e.g. one to ten hours the single activated bacteria can be added to the circulating water.
Mixed cultures of dry bacteria have proven to be particu-a ~ooso~s ~.-- 5 larly suitable for the inventive method Which are marketed under the name "DBC plus" by Enviroflow Flow Laboratories, Inc., A Flow General Company, McLean, Va., U.S.A.
The "DBC plus" mixed culture is selected in accordance with the nutrient offer in the circulating water. The flora analysis of the new "DBC plus" types of dry bacteria mixtures and the main taxonomic group is as follows: Aeromonas, Acinotobacter, Alcaligenes, Enterobacteria, Pseudomonas other gram-negatives, Bacillus, Lactobacillus, Micrococcus, Staphylococcus, Strepto-coccus and other gram-positives and those whose classification is questionable.
Thus, "DBC plus type A2" is particularly suitable for the circulating water of paper machines as well as for processes in petrochemistry Where phenolic compounds may pass into the cool-ing water.
Further, "DBC plus type L" is suitable for the cooling water circulation in refineries where hydrocarbons can break into the cooling water circulation, as well as in the cooling circulation of oil mills, i.e. in the processing of vegetable oils. Furthermore, "DBC plus type L1" is used in particular in cooling circulations in the chemical industry, especially when ketones must be expected in the cooling water.
The quantity of bacteria added to the circulating water based on the quantity of organic substances in the Water is preferably 1 to 101° bacteria per kg of the total organic car-bon (TOC) of the organic substances, in particular 10 to 109 bacteria per kg of TOC and most preferably 102 to 108 bacteria per kg of TOC.
In dry bacteria, in particular "DBC plus" bacteria, this corresponds to about 10-6 to 50 g per kg of TOC, or 10-5 to 5 g per kg of TOC, or 10-' to 0.5 g per kg of TOC.
Other additives are preferably also mixed into the circu-lating Water along with the bacteria. The addition of tensides was already referred to above for reducing the sessility of the bacteria and other microorganisms on the surfaces of the ma-chine parts. It is also advantageous to promote the growth of the added bacteria by adding supplines (cf. Hans G. Schlegel, "Allgemeine Mikrobiologie" ("General Microbiology"), 6th ed.
"""~" 1985, p. 174) .
The addition of lignosulfonates, as described in German Patent No. 34 47 686, can also be advantageous although no biocides at all are used in the inventive method.
It is also advantageous in the inventive method to add enzymes which catalyze the breakdown of the organic substances contained in the circulating water. The enzymes used may, for example, be amylases, proteases, pectinases, cellulases, acylases, aldolases, alcanoxygenases, alkoholdehydrogenases, dehydrogenases, phosphatases, dehydrases, dehydratases, oxygenases, oxidases, permeases, kinases, carboxylases, lipases, phosphorylases, decarboxylases, reductases, oxidoreductases and hemicellulases.
The type of enzyme used depends on the application in question. For example, cellulases and hemicellulases preferably added to the white water of paper machines, while proteases are added to the cooling circulation in food processing, and lipases are added in particular to the cooling circulation in oil mills and other food processing plant.
The quantity of enzyme or enzymes added is preferably IU (International Units) to 500,000 IU per kg of TOC.
However, a quantity of maximally 10,000 or maximally 1000 IU
per kg of TOC is generally sufficient.
Further, a high content of dissolved oxygen in the circulating water is advantageous in the inventive method.
This accelerates the breakdown of the organic substances, thereby reducing the high load of these substances in the circulating water.
The oxygen can be supplied by aerating the circulating water with oxygen or by adding oxygen-releasing compounds, such as H202 or peroxides.
In the inventive method, the bacteria and further additives are preferably added continuously, which also includes the addition of smaller portions over time. This maintains the dominance of the added type of bacteria, thereby ensuring the process stability.
The bacteria and other additives may be added in time-proportional fashion, i.e. a certain amount preferably added continuously for a certain time, e.g. one day. Instead, they may also be continuously added in proportion to quantity.
That is, the TOC content is constantly analyzed ,possibly automatically, and the amount of added bacteria and other additives regulated in accordance with the analyzed TOC
content. Addition in proportion to quantity is preferable in particular for processes involving great fluctuations of the TOC content.
The invention is also based on a system for carrying out the inventive method, comprising a feed area in which the bacteria and/or other microorganisms and possibly the other additives are continuously added to the circulating water.
The feed area is preferably provided with a dosing means for automatically adding the microorganisms or bacteria, and optionally one or more other dosing means for automatically adding the other additives.
The individual components are fed in places as separate as possible in the feed area. For example, if proteases are used as the enzymes, they are added at a place upstream of the place where the bacteria are added. This is because the proteases are intended to settle with their active centers on the organic substances in the circulation and catalyze their breakdown. If the active centers of the proteases came in direct contact with the added bacteria, they would accelerate the breakdown of bacterioprotein and thus damage the added bacteria.
For this reason. H202, for example, is added at a place or at places located upstream of the place where the enzyme and the bacteria are added, since H202 in excessive concentration is a cellular poison and can damage the enzymes.
The addition of H202 is therefore preferably distributed over the entire system.
The inventive method is suitable in particular for reducing the buildup of slime and film in plant which circulates the white water of paper machines, and in plant which circulates cooling water.
It is also based on a system for carrying out this method and applications of this method.
Water circulation, in particular the increasingly used closed circulation of the white water on paper machines and cooling water circulation, always involves the problem that and/or film builds up on solid surfaces and in the liquid phase (cf. "Vortrage anla(3lich des 5. PTS-WAF-Lehrgangs, Fortbildungskurs zur Wasser- and Abwasseranalytik, Kontrolle des Einsatzes von mikrobioziden finder Papiererzeugung". ("Lectures in the Fifth PTS-WAF
Course, Further Education on Water and Waste Water Anlysis, Control of the Use of Microbiocides in Paper Production"), organized by the "Papiertechnische Stiftung," Munich, and Hans-Dietrich Held "Kuhlwasser" ("Cooling water") , Vulkan-Verlag Dr. W. Claussen, Essen, 1977, p. 70 to 73).
In the closed circulation of the white water increasingly used for paper machines, microorganisms find very good growth conditions due to the high organic and inorganic nutrient offer present in the white water, and a favourable environment, i.e. a high temperature, a pH value close to the neutral point and a supply of oxygen. Since many of the microorganism are not present in the circulating water as free organisms but settle on the fibrous, filling and fine material and the surfaces of the machine parts, such as pipes, vessels and pumps, there is an undesirable buildup of slime and film. When the slime or film is detached from the surfaces this often leads to the formation of lumps and thus possibly to holes in the paper web. This weakens the paper web, i.e. cause it to tear, thereby resulting in machine standstills. In order to prevent this buildup of slime and film it is known to add biocides, lignosulfonates or enzymes to the white water.
,~~
The use of biocides suppresses the growth of the microorganisms and partly damages them. However, the use of biocides is increasingly criticized. The greater the amount of biocide is, the more damage is done to the environment to which the white water is fed when the circulation is emptied.
Since microorganisms tend to become resistant to biocides it is also necessary to change the biocide substances frequently and/or increase their amount. This means a considerable increase in pollution or considerable costs, e.g. for a following adapted clarification plant or a drainage ditch.
Lignosulfonates are used as so-called "complexers"
which prevent the microorganisms from taking in food under certain conditions. Sometimes a biocide must also be used with the lignosulfonate, but in a much smaller amount then if used alone (cf. German patent no. 34 47 686). The problems of biocides thus continue to exist in a milder form.
Enzymes are added to the white water circulation in order to convert the high molecular polymers, which promote the build up of slime and film, into low molecular products which are uncritical for the buildup of slime and film. This method is environmentally safe but has not proved useful in large scale application, presumably because it only allows for a brief reduction of viscosity, while the hydrolysis or other low molecular products formed by the enzymes may even be preferred food for the slime forming microorganism.
Cooling water circulation involves the problem that leaks or points of contact with the circulating product stream, such as the condensation of gases in the cooling circulation which arise during vaporization processes in the circulating product stream, cause organic impurities to pass into the circulating water in most cases. This again lead to the growth of microorganism. Together with the organic and inorganic impurities, these microorganism chiefly form deposits on the surfaces of the heat exchanges, thereby drastically reducing the heat transmission. This necessitates frequent and expensive cleaning of the heat exchangers to maintain the necessary removal of heat for the particular process. In this case, too, biocides are mainly used to reduce the buildup of slime and film on the ~,a.., , ...
~;0~35(~~9 heat exchanger surfaces.
The invention is therefore based on the problem of finding an environmentally safe method for plant with water circulation which reduces the buildup of slime and film in the water circu-lation, thereby reducing the stop periods of the plant.
This problem is solved by a method of the type stated at the outset whose characterizing feature is that microorganisms are added to the circulating water.
Surprisingly enough, when the inventive method is carried out and microorganisms are selectively added to the circulating water in accordance with its organic load, there is a clear reduction in the buildup of slime and film on solid surfaces and in the liquid phase, although the addition of microorgan-isms constitutes an increased organic contamination of the cir-culating water.
The inventive method presents an environmentally safe way of treating the most diverse types of circulating water in such a way as to largely reduce the buildup of slime and film and shorten the stop periods of the plant.
Microorganisms suitable for the inventive method have proved to be in particular bacteria, mainly bacteria of the following taxonomic groups: Aeromonas/Vibrio, Acinetobacter, Alcaligenes, Enterobacteria, Pseudomonas, Bacillus, Lactobacil-lus, Micrococcus, Staphylococcus and Streptococcus, in particu-lar Aeromonas hydrophila, Acinetobacter calcoacetica, Alcalige-nes eutrophus; Escherichia coli; Nitrosomonas, Nitrobacter, Bacillus megaterium, B. macerans, B. polymyra, B. subtilis, B.
stearothermophilus, B. coagulans, B. circulans, B. cereus, B.
pasteurii; Chromatium; Pseudomonas arvilla, P. putida, P.
stutzeri, P. fluorescens, P. denitrificans, P. aeruginosa; Zoo-gloea; Zymomonas; Leuconostoc; Proteus vulgaris; Sporosarcina ureae; Rhodopseudomonas; Nocardia; Mycobacterium; Flavobacte-rium; Agrobacterium; Cytophaga; Sporocytophaga; Streptomyces;
Micromonospora; Clostridium pectinovorum, C. felsineum; Azoto-bacter: Streptococcus; Cellulomonas; Azomonas; Rhizobium; Thio-bacillus, Thiothrix, Streptobacillus, Spaerothilus, Enterobac-ter aerogenes; Serratia; Propionibacterium; Micrococcus; Ar-throbacter, Corynebacterium, Brevibacterium; Photobacterium;
Xanthomonas, Chromobacterium, Vibrio, Acetotbacter, Lactobacillus. In the following, bacteria will therefore be primarily referred to.
However, other microorganisms can also be used in the inventive method, such as fungi, such a fungi of the groups Myxomycetes, Phycomycetes, Ascomycetes, Basidiomycetes, Deuteromycetes, in particular Acrasiales, Asperigillus niger, A. Oryzae, A. wentii; Candida lipolytica, tropicalis;
Saccharomyces; Chaetomium; Cryptococcus.
One can also use mixtures of bacteria or of fungi or mixtures of bacteria with fungi.
The bacteria use according to the invention are nonsessile bacteria, i.e. microorganisms or bacteria are selected which show no, or only little, tendency to settle on surfaces compared to the microorganism or bacteria forming slime and film in the plant.
The tendency of the added microorganisms or bacteria to settle on surfaces can be further reduced according to the invention by adding tensides to the circulating water. A
suitable tenside has in particular proved to be a tenside called "Konsan" available from KW Kalos & Wiechmann GmbH, Hude.
According to the inventive method the bacteria are added in a relatively large quantity. Furthermore, they are not used in lumps, flakes or colonies but preferably as single bacteria. Due to their large quantity and their single form the bacteria have a very large total surface, so that they lead to strong absorption or intake of the nutrients existing in the circulation. This results in a competition for the food present in the circulating water, which is won by the added nonsessile bacteria, due to their high food intake, and lost by the slime and film forming microorganisms.
In order to allow the bacteria to be added to the circulating water in an optimal single form, the invention preferably assume dry bacteria or mixed cultures or dry bacteria which are stirred by stirring means, well known in the art, into a predetermined volume, whereby after an activation period of e.g. one to ten hours the single activated bacteria can be added to the circulating water.
Mixed cultures of dry bacteria have proven to be particu-a ~ooso~s ~.-- 5 larly suitable for the inventive method Which are marketed under the name "DBC plus" by Enviroflow Flow Laboratories, Inc., A Flow General Company, McLean, Va., U.S.A.
The "DBC plus" mixed culture is selected in accordance with the nutrient offer in the circulating water. The flora analysis of the new "DBC plus" types of dry bacteria mixtures and the main taxonomic group is as follows: Aeromonas, Acinotobacter, Alcaligenes, Enterobacteria, Pseudomonas other gram-negatives, Bacillus, Lactobacillus, Micrococcus, Staphylococcus, Strepto-coccus and other gram-positives and those whose classification is questionable.
Thus, "DBC plus type A2" is particularly suitable for the circulating water of paper machines as well as for processes in petrochemistry Where phenolic compounds may pass into the cool-ing water.
Further, "DBC plus type L" is suitable for the cooling water circulation in refineries where hydrocarbons can break into the cooling water circulation, as well as in the cooling circulation of oil mills, i.e. in the processing of vegetable oils. Furthermore, "DBC plus type L1" is used in particular in cooling circulations in the chemical industry, especially when ketones must be expected in the cooling water.
The quantity of bacteria added to the circulating water based on the quantity of organic substances in the Water is preferably 1 to 101° bacteria per kg of the total organic car-bon (TOC) of the organic substances, in particular 10 to 109 bacteria per kg of TOC and most preferably 102 to 108 bacteria per kg of TOC.
In dry bacteria, in particular "DBC plus" bacteria, this corresponds to about 10-6 to 50 g per kg of TOC, or 10-5 to 5 g per kg of TOC, or 10-' to 0.5 g per kg of TOC.
Other additives are preferably also mixed into the circu-lating Water along with the bacteria. The addition of tensides was already referred to above for reducing the sessility of the bacteria and other microorganisms on the surfaces of the ma-chine parts. It is also advantageous to promote the growth of the added bacteria by adding supplines (cf. Hans G. Schlegel, "Allgemeine Mikrobiologie" ("General Microbiology"), 6th ed.
"""~" 1985, p. 174) .
The addition of lignosulfonates, as described in German Patent No. 34 47 686, can also be advantageous although no biocides at all are used in the inventive method.
It is also advantageous in the inventive method to add enzymes which catalyze the breakdown of the organic substances contained in the circulating water. The enzymes used may, for example, be amylases, proteases, pectinases, cellulases, acylases, aldolases, alcanoxygenases, alkoholdehydrogenases, dehydrogenases, phosphatases, dehydrases, dehydratases, oxygenases, oxidases, permeases, kinases, carboxylases, lipases, phosphorylases, decarboxylases, reductases, oxidoreductases and hemicellulases.
The type of enzyme used depends on the application in question. For example, cellulases and hemicellulases preferably added to the white water of paper machines, while proteases are added to the cooling circulation in food processing, and lipases are added in particular to the cooling circulation in oil mills and other food processing plant.
The quantity of enzyme or enzymes added is preferably IU (International Units) to 500,000 IU per kg of TOC.
However, a quantity of maximally 10,000 or maximally 1000 IU
per kg of TOC is generally sufficient.
Further, a high content of dissolved oxygen in the circulating water is advantageous in the inventive method.
This accelerates the breakdown of the organic substances, thereby reducing the high load of these substances in the circulating water.
The oxygen can be supplied by aerating the circulating water with oxygen or by adding oxygen-releasing compounds, such as H202 or peroxides.
In the inventive method, the bacteria and further additives are preferably added continuously, which also includes the addition of smaller portions over time. This maintains the dominance of the added type of bacteria, thereby ensuring the process stability.
The bacteria and other additives may be added in time-proportional fashion, i.e. a certain amount preferably added continuously for a certain time, e.g. one day. Instead, they may also be continuously added in proportion to quantity.
That is, the TOC content is constantly analyzed ,possibly automatically, and the amount of added bacteria and other additives regulated in accordance with the analyzed TOC
content. Addition in proportion to quantity is preferable in particular for processes involving great fluctuations of the TOC content.
The invention is also based on a system for carrying out the inventive method, comprising a feed area in which the bacteria and/or other microorganisms and possibly the other additives are continuously added to the circulating water.
The feed area is preferably provided with a dosing means for automatically adding the microorganisms or bacteria, and optionally one or more other dosing means for automatically adding the other additives.
The individual components are fed in places as separate as possible in the feed area. For example, if proteases are used as the enzymes, they are added at a place upstream of the place where the bacteria are added. This is because the proteases are intended to settle with their active centers on the organic substances in the circulation and catalyze their breakdown. If the active centers of the proteases came in direct contact with the added bacteria, they would accelerate the breakdown of bacterioprotein and thus damage the added bacteria.
For this reason. H202, for example, is added at a place or at places located upstream of the place where the enzyme and the bacteria are added, since H202 in excessive concentration is a cellular poison and can damage the enzymes.
The addition of H202 is therefore preferably distributed over the entire system.
The inventive method is suitable in particular for reducing the buildup of slime and film in plant which circulates the white water of paper machines, and in plant which circulates cooling water.
Claims (25)
1. A method for reducing the buildup of slime and film in a plant which circulates water, characterized in that microorganisms are added to the circulating water.
2. The method of claim 1, characterized in that the microorganisms added are bacteria or mixtures of bacteria.
3. The method of claim 2, characterized in that bacteria of the taxonomic groups Aeromonas/Vibrio Acinetobacter Alcaligenes Enterobacteria Pseudomonas Bacillus Lactobacillus Micrococcus Staphylococcus Streptococcus or mixtures thereof are added.
4. The method of claim 2 or 3, characterized in that the bacteria used are dry bacteria or mixed cultures of dry bacteria.
5. The method of claim 4, characterized in that the mixed cultures of dry bacteria used are mixed cultures available under the name "DBC plus" from Enviroflow Flow Laboratories Inc., U.S.A.
6. The method of any one of the above claims, characterized in that the quantity of microorganisms or bacteria added to the circulating water based on the quantity of organic substances in the circulating water is 1 to 10 10 microorganisms or bacteria per kg of the total organic carbon (TOC) of the organic substances.
7. The method of claim 6, characterized in that the quantity of microorganisms or bacteria added is 10 to 10 9 microorganisms or bacteria per kg of TOC.
8. The method of claim 7, characterized in that the quantity of microorganisms or bacteria added it 10 2 to 10 8 microorganisms or bacteria per kg of TOC.
9. The method of any one of the above claims, characterized in that the microorganisms or bacteria are added to the circulating water in the form of free microorganism or bacteria to a very large extent.
10. The method of any one of the above claims, characterized in that further additives in the form of enzymes, supplines, tensides and/or lignosulfonates are added to the circulating water.
11. The method of claim 10, characterized in that the quantity of the enzyme or enzymes added is 10 IU
(International Units) to 500,000 IU per kg of TOC.
(International Units) to 500,000 IU per kg of TOC.
12. The method of claim 11, characterized in that the quantity of the enzyme or enzymes added is 10 to 10,000 IU per kg of TOC.
13. The method of claim 12, characterized in that the quantity of the enzyme or enzymes added is 10 to 1000 IU per kg of TOC.
14. The method of any of the above claims, characterized in that oxygen is additionally added to the circulating water.
15. The method of claim 14, characterized in that the oxygen is added by aerating the circulating water with air or oxygen or in the form of oxygen-releasing compounds.
16. The method of any one of the above claims, characterized in that the addition of one or more of the microorganisms, the other additives and the oxygen takes place continuously.
17. The method of claim 16, characterized in that the addition of one or more of the microorganisms, the other additives and the oxygen takes place in proportion to time or to quantity.
18. A system for carrying out the inventive method of any one of the above claims, characterized in that a feed area in which the microorganisms or bacteria are added continuously to the circulating water.
19. The system of claim 18, characterized in that the feed area is provided with a dosing means for adding the microorganisms or bacteria.
20. The system of claim 18 or 19, characterized in that the dosing means for adding the microorganisms or bacteria has a stirring means for separating the microorganisms or bacteria into single form.
21. The system of any one of claims 18 to 20, characterized in that the microorganisms or bacteria, on the one hand, and the other additives, on the other hand, are added at separate places in the feed area.
22. The application of the method of any one of claims 1 to 17 in plant which circulates the white water of paper machines.
23. The application of the method of any one of claims 1 to 17 in plant which circulates cooling water.
24. The system of claim 18, wherein one or more other additives are added continuously to the circulating water.
25. The system of claim 19, wherein one or more other dosing means are provided for adding the other additives.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DEP3841596.8 | 1988-12-09 | ||
| DE3841596A DE3841596A1 (en) | 1988-12-09 | 1988-12-09 | METHOD FOR REDUCING SLIME AND COATING IN PLANTS |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2005029A1 CA2005029A1 (en) | 1990-06-09 |
| CA2005029C true CA2005029C (en) | 1999-09-14 |
Family
ID=6368853
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002005029A Expired - Fee Related CA2005029C (en) | 1988-12-09 | 1989-12-08 | Method for reducing the buildup of slime and film in plant |
Country Status (5)
| Country | Link |
|---|---|
| EP (1) | EP0372520B2 (en) |
| AT (1) | ATE81838T1 (en) |
| CA (1) | CA2005029C (en) |
| DE (2) | DE3841596A1 (en) |
| FI (1) | FI102161B (en) |
Families Citing this family (22)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2687659B1 (en) * | 1992-02-24 | 1994-08-26 | Texel | PROCESS FOR THE TREATMENT OF FLORA CONTAMINATING PAPER CIRCUITS USING BACTERIA. |
| CA2106609A1 (en) * | 1992-09-28 | 1994-03-29 | Irene Yeatman Aldridge | Proteases to inhibit and remove biofilm |
| DE4410271C2 (en) * | 1994-03-24 | 1999-02-25 | Lumos Trading & Investments Co | Process for reducing the formation of slime and deposits in systems in which water from paper and pulp machines is circulated, as well as in systems in which cooling water is circulated |
| DE4421504C2 (en) * | 1994-06-20 | 1998-04-16 | Lumos Trading & Investments Co | Process for the preservation of aqueous solutions or dispersions, plant for carrying out the process and its use |
| FR2726546B1 (en) * | 1994-11-07 | 1997-01-31 | Europ Services | DEVICE FOR CURING AND / OR DESCALING WASTEWATER PIPES BY CIRCULATION OF A BACTERIAL CULTURE IN THEIR BREAST, AND PROCESS FOR IMPLEMENTING THE SAID DEVICE |
| DE19501350C1 (en) * | 1995-01-18 | 1996-04-04 | Henkel Kgaa | Reducing deposit of mucin(s) in circulating |
| FR2762593B1 (en) * | 1997-04-25 | 1999-07-30 | Rhodia Chimie Sa | PROCESS FOR REDUCING OR DELETING BACTERIAL ORIGIN DEPOSITS IN CLOSED CIRCUIT WATER INSTALLATIONS |
| JP3452347B2 (en) * | 1998-08-06 | 2003-09-29 | 株式会社東京バイオックス | Water purification agent and water purification method |
| AU2001269939A1 (en) * | 2000-06-19 | 2002-01-02 | Novozymes Biotech, Inc. | Methods for eliminating the formation of biofilm |
| WO2002032815A2 (en) * | 2000-10-17 | 2002-04-25 | Earth Alive Resources Inc. | Treatment of sludge from wastewater treatment facilities |
| DE10062812B4 (en) * | 2000-12-18 | 2009-07-09 | Georg Fritzmeier Gmbh & Co. Kg | Microbiological composition |
| DE10221225A1 (en) * | 2002-05-13 | 2003-11-27 | Fritzmeier Georg Gmbh & Co | Composition and process for eliminating mold infestation |
| TWI297052B (en) | 2002-10-18 | 2008-05-21 | Yuen Foong Yu Paper Mfg Co Ltd | |
| DE10252634A1 (en) * | 2002-11-11 | 2004-05-27 | Umwelttechnik Georg Fritzmeier Gmbh & Co. | Purification of sewage or other substances laden with harmful organic matter and detergent or clarifying agent also useful laundry and cleaning surfaces involve introduction of photosensitizer releasing singlet oxygen when stimulated |
| US20080233093A1 (en) * | 2007-03-23 | 2008-09-25 | Novozymes Biologicals, Inc. | Preventing and Reducing Biofilm Formation and Planktonic Proliferation |
| DE102012223682A1 (en) | 2012-12-19 | 2014-06-26 | BSH Bosch und Siemens Hausgeräte GmbH | Water-bearing domestic appliance with internal surface and method of operation |
| DE102014220554A1 (en) | 2014-10-10 | 2016-04-14 | BSH Hausgeräte GmbH | Method for controlling microorganisms in a water-conducting domestic appliance and household appliance suitable therefor |
| DE102015223583B4 (en) | 2015-11-27 | 2022-08-25 | BSH Hausgeräte GmbH | Water-bearing household appliance with an electrochemically polarizable inner surface and method for its operation |
| DE102015223616B4 (en) | 2015-11-30 | 2019-08-14 | BSH Hausgeräte GmbH | Household appliance with electrolytic biofilm control and method for its operation |
| DE102020213078A1 (en) * | 2020-10-16 | 2022-04-21 | Sms Group Gmbh | Process for eliminating legionella from cooling circuit water contaminated with organic substances and inorganic particles |
| DE102020213077A1 (en) * | 2020-10-16 | 2022-04-21 | Sms Group Gmbh | Process for the treatment of cooling circuit water contaminated with organic substances and inorganic particles |
| EP4403526A1 (en) | 2023-01-23 | 2024-07-24 | BlueActivity® GmbH | Process for water treatment in open recooling plants |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2472540A1 (en) * | 1979-12-28 | 1981-07-03 | Ribaud Marcel | Anaerobic biological system for purificn. of effluent - using specified mixed culture which is fed continuously |
| DE3447686C1 (en) * | 1984-12-28 | 1986-10-30 | Jörg Dipl.-Ing. Dr. Seewalchen Oberkofler | Process for reducing slime formation in systems with a water cycle and application of the process |
| FR2607490B1 (en) * | 1986-11-28 | 1990-04-27 | Brun Christian | BIOLOGICAL PROCESS FOR THE TREATMENT OF VEGETABLE AND ANIMAL FAT BY BACTERIA IN PURIFICATION PLANTS AND THE IMPLEMENTATION OF SAID PROCESS |
| US4810385A (en) * | 1987-05-12 | 1989-03-07 | Sybron Chemicals, Inc. | Device for seeding bacterial cultures to systems to assist in biodegrading waste |
-
1988
- 1988-12-09 DE DE3841596A patent/DE3841596A1/en active Granted
-
1989
- 1989-12-05 FI FI895814A patent/FI102161B/en not_active IP Right Cessation
- 1989-12-06 EP EP89122477A patent/EP0372520B2/en not_active Expired - Lifetime
- 1989-12-06 DE DE8989122477T patent/DE58902560D1/en not_active Expired - Lifetime
- 1989-12-06 AT AT89122477T patent/ATE81838T1/en not_active IP Right Cessation
- 1989-12-08 CA CA002005029A patent/CA2005029C/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| FI102161B1 (en) | 1998-10-30 |
| CA2005029A1 (en) | 1990-06-09 |
| ATE81838T1 (en) | 1992-11-15 |
| FI102161B (en) | 1998-10-30 |
| EP0372520A3 (en) | 1990-09-12 |
| DE58902560D1 (en) | 1992-12-03 |
| EP0372520B1 (en) | 1992-10-28 |
| EP0372520B2 (en) | 1999-06-16 |
| DE3841596A1 (en) | 1990-06-13 |
| DE3841596C2 (en) | 1991-05-29 |
| EP0372520A2 (en) | 1990-06-13 |
| FI895814A0 (en) | 1989-12-05 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| MKLA | Lapsed |