DE2601701A1 - IMPROVED PROCEDURE FOR ADJUSTING THE NITRIFICATION EFFECTIVENESS OF A BIOLOGICAL FILTER - Google Patents

Description

PATENT LAWYERS

DipL-lng. P. WiRTH ■ Dr. V. SCHMIED-KOWARZ! K DipWng. G. DANNENBERG Dr. P. WEINHOLD Dr. D. GUDEL

281134 6 FRANKFÜRT AM MAIN

TELEPHONE COSH) _{? 870] 4} GR. ESCHENHEIMER STRASSE 39

SK / SK

PA-706

Syntex (U.S.A.), Inc.

3401 Hillvieui Avenue

PaIo Alte, ca.94304 / USA

Improved procedure for setting the Nitrification efficiency of a biological

The present invention relates to an implement for Reduction of the time necessary for nitrification activity ("nitrifying activity") of a biological filter and the reliability of the setting of the biological filter Filters to improve. The process can be used in treatment in wastewater treatment plants, in aquaculture systems closed loop and commonly used in water purification processes; it requires the setting of a corresponding one pH and temperature range of the water running through a biological filter medium, the addition of an output quantity of an autotrophic nitrifying bacterium together with etuia 0.1-633 ppm copper ions and etuia 1-560 ppm iron ions irr, circulating water, the circulation of water through the biological filter medium until the concentration of ammonia and Nitrite drops below 0.1 'ppm, and the subsequent use of the biological filter at will. The present invention

609831/0862

dung further refers to its packaged combination of a specific source of copper ions in combination with a broader specific soluble iron source and an activating amount of nitrifying bacteria.

It is well known that in a biological filter such as that used in a closed loop aquaculture system ("closed-loop aquaculture system") or an waste water treatment plant is used, autotrophic bacteria are used to convert the ammonia present in the water into nitrite and the to convert the nitrite obtained into nitrate. In the system ammonia usually appears from the heterotrophic breakdown of the organic Waste material. In contrast to heterotrophic bacteria, the autotrophic bacteria require an inorganic substrate as an energy source, i.e., either ammonia in the case of Nitrosomonas sp. or nitrite in the case of Nitrobacter sp. and use carbon dioxide as their only source of cellular carbon. Nitrosomonas oxidize ammonia to nitrite and nitrobacter oxidize Nitrite to nitrate, both reactions showing a decrease in free energy.

It is also known that biological filters can be used for wastewater treatment for the purpose of water purification. So describes E.g. US PS 1,751,459 suggests successive stages of biological treatment of wastewater for the purpose of breaking down the main groups polluting constituents in the wastewater, it should be noted that ammonium salts are caused by Nitrosomonas and Nitrobacter bacteria oxidized to nitrate. US PS 2,562,510 describes that wastewater after a primary filtration of a seepage filter treatment can be subjected to which the

609831/0862

pourable material on a coarse medium with located on it Nitrifying bacteria for the biological oxidation of the Ammonia is sprayed onto nitrate. US Pat. No. 3,337,452 teaches that sewage is rajt before biological treatment Manganese dioxide can be treated for the purpose of oxidation, after which one can use Küpferoxid or a soluble cupro salt a pH of 1-3 then the manganese dioxide again by treatment can precipitate with an oxidizer at a higher pH such as 10.

US Pat. No. 3,723,304 describes a living algae cushion as a finely divided and also biological filter. The US reissue PS 27 721 teaches a method, sewage through a Series of seepage sand-gravel filters for aerobic metabolism of the wastewater through. U.S. Patent No. 3,763,038 describes the importance of using ferric ions to form a flocculant described that organic particles precipitate and aerobic bacteria grow on the precipitated particles allows. US PSS 3,835,813 and 3,661,262 discuss the use of biological filters in water purification for aquaculture systems with a closed loop.

Although the above patents use aerobic and anaerobic bacteria in the purification of water with a source of ammonia, none teaches a method for the establishment of an autotrophic bacterial colony on a biological filter medium or for a substantial reduction the time required to establish such a colony.

6 0 9 8 31/0862

In the article by H.A. Painter in "Water Research", Pergamon Press, 1970, Vol. 4, Pages 393-450, it is pointed out that the Growth of autotrophic nitrifying organisms very slowly and the yield of cells per unit of oxidized energy source is low. Some authors consider this to be inevitable in the autotrophic way of life, while others aim to achieve a higher growth rate under the correct, However, believe previously unknown conditions. Although this article indicates that phosphate, magnesium and Iron is known from Nitro'somonas and Nitrobacter bacteria and calcium and copper are needed by Nitrosomonas there is no indication of the naheley »; that the setting of the Nitrification activity in an autotrophic bacterial colony could be improved by a method as proposed by the present invention. It has been found that by using of the particular method according to the invention for setting the maximum nitrification activity of an autotrophic bacterial colony required time can be reduced by a factor of almost 3 and that the nitrifying activity of the Colony can be reliably reproduced over and over again.

The present invention relates on the one hand to a method characterized in that water is passed through a biological filter medium; the temperature of the water to about 5-35 ° C. and the pH of the same sets and maintains at about 7.0-9.0; an initial amount of an autotrophic nitrifying organism, e.g. Nitrosomonas and nitrobacteria together with a effective source of ammonia for the bacteria, sufficiently soluble

609831/0862

Copper salt to make a solution of about in the circulating water Produce 0.1-630 ppm copper, and enough iron to produce a solution of about 1-560 ppm iron in the circulating water, inflicts;

the water circulates through the biological filter, the concentration of ammonia and nitrite drops below 0.1 ppm; and then used the biological filter for the desired purpose. The temperature is preferably between about 27-3O ⁰ C. the pH value between about 8-9, the ammonia (as NH Cl) is present in the water in a concentration of 1-5 ppm, the copper (as CuSD) is in present at a concentration of about 0.1-0.3 ppm, which chelates iron (with ethylenediamine-etraacetic acid = EDTA) is present at a concentration of about 1.0-2.0 ppm, and this biological filter is used in the process used to purify water in a closed loop aquaculture system. The experience is particularly useful if, after the addition of NH.Cl and CuSO, the water is circulated until NO ~ is found, whereupon the iron ions are added.

Furthermore, the present invention relates to a new combination pack from

a container of an ammonia source;

a container of a copper source; and a container of an iron source

which are each present in sufficient concentration to achieve the to give in the l / experienced suitable, desired amount.

609831/0862

The method of the invention can be used to increase the activity a biological filter used in any water purification system. According to the invention, the means The term "biological filter" means any device with a medium to which autotrophic bacteria easily bind or attach, so that oas a nitrogen source (ammonia, mainly as ammonium ions NH. ) containing water touch the bacteria and the ammonia is converted into nitrite (NO) ions which in turn are converted into nitrate ions (f-JO ^ ").

In a system using a biological filter, the nitrogen source is "organic nitrogen, the one in the case."

an aquaculture system with a closed loop made of the impact products of marine animals is available. While the "biological filter" is mainly the location of the oxidation of Ammonia is involved in autofcrophic bacteria (presumably there are at least 100 times as many autotrophic bacteria in the medium bound as are suspended in the water), there are probably also some heterotrophic bacteria on the filter medium and with certainty present in the water. So one can see the "biological filtration" in the system as mineralization of organic nitrogenous compounds, View nitrification and denitrification by bacteria in the water and on the filter media. Although a certain one If denitrification occurs in the autotrophic bacteria, it is believed to be minimal.

Usually the medium can be porous, such as polyurethane foam or cellulosic or polymeric fibrous material, the medium however, it is preferably an aggregate of materials with a hard, smooth surface, such as stones, pebbles, or other inorganic,

609831/0862

stable, practically non-disintegrable materials, e.g. Gravel, quartz pebbles, sand, etc.

The size of the materials used as the filter medium is important. If the grain size is too small, the circulation through the bed will be impaired and debris will accumulate and the Can cover the bed surface} thereby forming channels of the least resistance through which the water runs preferentially »

The result is unreliable oxidation and the formation of areas where the growth of aerobic bacteria is inhibited u / ird and thus the effect of the biological filter is reduced will »Therefore the size should not be less than 2 mm and not more than 50 mm. The shape of the used as a biological medium The grain is preferably angular so that there is a larger surface area for bacteria accumulation results. Coarse, angular gravel is rubbed off by water compared to fine, smooth gravel Gravel preferred.

The method according to the invention can thus be applied to the biological filters used in wastewater treatment (cf., for example, the submerged filters described in "3ourn. Of Water Pollution Control" 44 (11), pages 2086-2102 by RT · Haug 'and PL McCarty ) or to create a biological filter used in the home aquarium; See aquariums which contain a filter located under the gravel in the rock medium, as described in "Fish and Invertrebrate Culture j Water Management in Closed Systems" by SH Spotte, published by Wiley Interscience, · (1970), pages 8-13 _f will. The method according to the invention is also suitable for adjusting the nitrification effect of biological filters, -as they'z.B. in U.S. Patent 3,841

609831/0862

and in biological filters as described in US patent applications Ser. No. 423 720 of Oct. 4, 1973, 439 094 of Feb. 4, 1974, 512 384 of Oct. 7, 1974 and 518 821 of October 29, 1974, the relevant material of these documents for the present case herewith is included in the present application.

According to the invention, a biological filter is "set", can he continuous nitrification of the in the system in which he is supposed to work, formed ammonia can carry out * So he will die in a closed loop aquaculture system Maintain levels of NHL and NO ~ at values that are non-toxic to the animals bred in the Sys Lern.

When adjusting the nitrification effectiveness of the biological To filter it is usually necessary to use a biological filter medium to nitrify bacteria (Nitrosomonas sp. And Nitrobacter sp.) and a sufficient source of nitrogen (NH.) To circulate through the medium in order to supply enough nutrition for the bacteria to multiply. Usually this is done by one takes part of the medium of an active biological filter or ordinary garden soil or even sewage sludge and added to the biological filter medium to be set. Whether on a small scale for use in a home aquarium or on a large scale takes place in a wastewater treatment plant, so are the results are not entirely predictable and usually the minimum time necessary for the bacteria to settle safely is about 30 days. Are the animals placed in the aquarium before this time or will it be treated using the biological filter? Circulate wastewater through the biological filter beforehand.

609831/0862

If there are not enough bacteria to cope with the nitrogenous product in the water, the water obtained is unsuitable for discharge to the environment in the case of a sewage treatment plant or for reuse by the aquatic animals in the case of the home aquarium not suitable. The method according to the invention not only makes it possible to be certain that the biological activity of the filter has been clearly set, but the time required to set the biological activity is reduced significantly, usually by a factor of at least 2 to 3. For example, it has been found that the adjustment of the biological activity of a biological filter, as described, for example, in US patent application Ser. ^w o »512 385 of Oct. 7, 1974, the necessary time can be reduced from the previously required, at least 30 days, to less than about 15 and sometimes 10 or less days.

Thus, the method of the invention is generally an improvement of the method for adjusting the nitrifying activity of the biological filter, which is characterized in that one

(a) Passes water through a biological filter mediura j

(b) the water to a temperature between about 5-35 ° C. and one adjusts and maintains a pH of about 7.0-9.0;

(c) a range of autntrophic nitrifying bacteria, such as Nitrosomonas and Nitrobacterbacteria together with sufficient Ammonia source for an ammonium ion concentration of about 0.1-5 ppm, sufficient soluble copper salt to form a solution of about 0.1-630 ppm copper in the circulating water

609831/0862

and enough iron to form a solution of about 1-560 ppm Adds iron in the circulating water to the biological filter medium;

(d) circulating water through the biological filter media until the concentration of ammonia and nitrite falls below G.1 ppm; and

(e) then the biological filter for the desired purpose used.

Although the method according to the invention for adjusting the activity of nitrifying bacteria is presented above as a series of stages, the stages need of course not to be carried out in the above literal order.

If, for example, the water to be used in the biological filter is already has the desired pH and temperature range, the filter Water, the bacteria, the ammonium source and the copper and iron salts are added at the same time. Or you can have an initial set of bacteria to the biological filter. while ■ the water temperature and pH value are set to the required range. As long as the pH or temperature at the beginning is such that To keep the bacteria alive, the steps outlined above do not need to be performed in the order shown.

In the biological filter, ammonium and nitrite are used according to the following Oxidized equations:

NH ₄ ⁺ ₊ 3/2 O ₂ ^ - ₊ ^ _{+ +} ^ _{n (1}}

NO ₂ + 1/2 O ₂ NO ₃ "

609831/0862

From these equations it can be seen that ammonia is responsible for the metabolism of Nitrosomonas is necessary and is the source of energy for these bacteria to grow. The nitrite, in turn, is that Energy source so that the Nitrobacter bacteria form nitrate. Consequently is the starting point for adjusting the nitrification effectiveness a biological filter of ammonia, and a source of ammonia must be present before the biological filter is set be. The known method for adjusting the nitrifying Bacterial effectiveness of a biological filter exists therein, the Nitrosomonas bacteria come into contact with a source of ammonium to bring, which can be an ammonium salt or an organic source of ammonium brought about by i.eterotrophic bacteria Ammonia is broken down.

In the method according to the invention, the ammonium source is preferred a water-soluble, non-toxic ammonium salt, such as ammonium chloride, phosphate, sulfate and carbonate. Sufficient salt is usually used to keep about 0.1-5 ppm ammonium ions in circulation To deliver water. A non-toxic ammonium salt is one whose anion in the concentrations used denotes Bacteria is not harmful.

The temperature for the operation of the biological filter must be acceptable for the multiplication and growth of the nitrifying bacteria. Be, i Nitrosotnonas bacteria seem to grow below 5 ° C. only nominal, and is specified in the range of 30 to about 36 ⁰ C. as optimal, whereas Nitrobacter has a growth range of approximately 4-45 ⁰ C. '. The temperature range in which the nitrifying Bak, criteria ammonia and nitrite together oxidize, but is usually between about 5-35 ⁰ C. The temperature of the biological

6 0 9831/086 2

Filter the circulating water preferably must correspond to the purpose of the filter., In the growth of rock shrimp for example, the desired temperature is about 25-35 ⁰ C, preferably about 27-3O ⁰ C, so that the biological filter should be set to this temperature and held . Furthermore, abrupt temperature changes of more than 5 C at once should be avoided as far as possible, since the bacteria are susceptible to such a shock and could easily be killed by such an abrupt change.

The set pH range must be such that the ■ bacteria do not be affected. Usually the pH of the water is kept between 7-9 with the pH adjustment similar to uie The temperature setting is such that the pH of the circulating water corresponds to the intended use of the biological filter. When breeding stone shrimp larvae ("praun larvae") in a closed loop aquaculture system as disclosed in US patent application Ser. No. 512 384 from 7.0ct. Described in 1974 is, the'pH value is between 8-9, so that it is appropriate to adjust the pH value during the initiation of the biological filter set to 8-9. The pH when adjusting the filter can be adjusted in any way that bacteria cannot harms and does not affect the intended use of the filter; For example, any salt can be used to maintain the pH as long as it is non-toxic and relatively soluble in the water system. In this case it represents a soluble Salt the pH faster than a less soluble salt. Suitable salts include, for example, alkali and alkaline earth salts of the carbonate series, whereby sodium carbonate due to its solubility

609831/0862

and lack of toxicity to bacteria and animals using the system in a closed loop aquaculture can be particularly effective. A buffered phosphate can also be used. First of all, the pH and temperature of the biological filter set to the desired fourth and there is a source of ammonium ions in the circulating water, then nitrosomonas and nitrobacter bacteria are added to the system, so that they can grow on the biological filter medium as described above.

A source of copper ions (Cu) is used simultaneously with the system or soon after the bacteria have been added, neither for the bacteria nor for the animals that pass through the biological filter can use treated water, non-toxic concentrates added. Usually the Nitrosomonas and Nitrobacter bacteria withstand up to 630 ppm copper in the system before they become toxic. Thus, with respect to the bacteria, 630 ppm is the upper limit; however, if the biological filter is used e.g. in a closed loop aquaculture system for the cultivation of Crustaceans, such as stone shrimp, should be used, a maximum of only 0.3 ppm should be used. This maximum value varies with the tolerance of the aquatic animals to be bred. As a source of copper, any soluble copper salt with a non-toxic one can be used Anion can be used, such as copper sulfate and copper nitrate and copper compounds, e.g. with EDTA are chelated.

Usually the water needed to adjust the nitrification activity is lacking a biological filter is circulated before the oxidation of ammonia to nitrite nitrite ions. While nitro

6 0 98 3 1/0862

bacterbacteria seem to need nitrite as their source of energy they don't need copper. So it is advisable to add copper along with a source of ammonium and the water long enough for the formation of a detectable concentration of nitrite ions to circulate in the circulating water. This usually takes 3 to 5 days, preferably about 4 days at 27-30 C. Da Nitrobacter does not require copper, this is the case with Nitrosomonas however it is important to have the copper at the beginning of the biological setting Add filters so that Nitrosomonas is the source of copper is available to accelerate the activity. Although both Nitrobacter and Nitrosomonas Using iron, it seems to be more important that the source of copper for the Nxtrosomonas bacteria when the filter is set for the first time. The iron source can then be added to the water circulating in the biological filter.

Any iron source which supplies iron ions (Fe) and does not precipitate out of the solution, for example as carbonate, can be used in the process according to the invention. An iron chelated with EDTA is particularly useful in this particular case; A product commercially available from the company Ciba-Geigy as SEQUESTRENE ^ has proven to be very suitable, the iron source being sodium ferricdiethyleneamine pentaacetate. The bacteria in the system can tolerate up to 560 ppm iron; and at least 1 ppm should be present for the bacteria to take advantage of its presence. However, the iron concentration in the circulating water must be compatible with the end use of the biological filter. So it is in a system

609831/0862

that the filter in an aquaculture system with closed Loop used for breeding shrimp, expedient that no more than 5 ppm iron in the circulating in the biological filter Water are present. As admonished above, the iron and copper sources can be added together or independently with the addition of copper first. In the latter case, the water will last long enough to form 0.1 ppm nitrite ions circulates, which usually takes up to 3-5 days. After finding nitrite ions, iron is added, and that Water is circulated, preferably an additional 6-7 days, before the detectable levels (i.e., ^ 0.1 ppm) of the nitrite ions are complete disappear from the system. During this time it is best if there are no animals present in the system that could harm the biological Use filters as the nitrite concentration can accumulate to a value that is harmful to the animals to be bred is.

Although other ions used by the bacteria are added to the system they have not shown the same effect on the bacterial recruitment effect as the iron and copper ions. Other materials to be added include phosphate in the form of sodium or molybdenum phosphate, magnesium ions, and molybdenum ions.

In order to finally determine whether the biological filter is working properly, that is circulated through the biological filter Water to determine the concentration of ammonia and nitrite

analyzed. Once the concentration of each of these materia If it falls below 0.1 ppm, the biological filter can be used for any purpose. .

609831/086 2

Methods for analyzing ammonia and nitrite are known and can be found in the following "references:

(1) "Standard Methods for the Examination of Waser and Waste Waser "from the American Public Health Assoc, American Water Waste Assoc. and Water Pollution Control Fed., issued by the American Public Health Association, 1015, 18th Street, N.W., Washingston, D.C. 2G036 (1971).

(2) "Method for Chemical Analysis of Waser and Wastes", Environmental Protection Agency, 197-1; National Environmental Research Center; Analytical Quality Control Lib. Cincinnati _s Ohio, 45268.

(3) R.G. Thomas and R'.L. Booth, "Selective Electrode Measurement of Amrr.jnia in Waser and Wastes ", Environmental Science and Tech., 7 (6), 1973, 523-526.

Where the biological filter in an aquaculture system with closed Loop, e.g. in a home aquarium, should be used ωό no system for performing NH or NO ~ measurements is available, learning can easily be done by man

(a) passes water through a biological filter medium;

(b) adjusts the water to a temperature of about 27-3O ⁰ C. and a pH value of 8-9 and maintains it at these values;

(c) this biological filter medium an initial amount of autotrophic nitrifying bacteria along with sufficient ammonium ions (e.g. NH.Cl) to form a concentration of about 4-5 ppm Add ammonium ions and sufficient copper ions (CuSO.) To form a concentration of 0.1-0.2 ppm Cu in the water;

609831/0862

(d) the water circulates for a minimum of 3 days and a maximum of 5 days (until the NO ₂ "ions are fixed);

(e) sufficient iron ions to produce about 1-2 ppm iron ions inflicts in the water;

(f) the water circulates for a minimum of 7 and a maximum of 9 days (until the NH ^ and WO ₂ "I ° ^{nen disappear); and}

(g) the filter as desired (e.g. by introducing aquatic animals, like fish in the aquarium).

The process of improving the effectiveness of a setting biological filter is particularly suitable for the breeding of aquatic animals such as fish, crustaceans, e.g. lobsters, lobsters, Prawns, mollusks and other aquatic animals. The process can be used on fresh or fresh and salt water systems. In general this procedure comprises the following stages:

Introduction of water into a suitable aquaculture tank; Introduction of the biological filter in liquid contact with the Water;

Adjustment and maintenance of the water at one temperature between about 5-35 ° C, preferably 27-30 ° C, and a pH between about 7.0-9.0, preferably 8-9; Addition of an initial quantity of nitrifying bacteria to the biological one Filters, along with a source of ammonia for a concentration of about 0.1-5.0 ppm;

Adding a soluble copper salt (to preferably about 0.1-0.3 ppm) and an iron salt (preferably to about 1-2 ppm), with copper and iron salts being present in concentrations,

609831/0862

which are non-toxic to the aquatic animals to be bred; Circulating the water through the biological filter until the concentration of ammonia and nitrite falls below G, 1 ppm; Introducing the aquatic animals into the container and feeding derseloen.

Where the biological filter gravel on a sub-gravel filter in one

it
other aquarium than / in the US patent applications Ser «Mos. 430

described
or 439 094 / is, the water is added to the aquarium and circulated by means of an air buoyancy pump or other device for water circulation (cf. the above-mentioned reference by SH Spotte "Water Management in Closed Systems" or the patent applications mentioned) to adjust the temperature and pH -Value r> it water to set the desired bet. Sources of Nitrosomonas and Nitrobacter are then added to the medium along with the ammonia quella and the copper and iron salts. The water is circulated through the filter to bring the ammonia and nitrite levels below 0.1 ppm. Then the aquatic animals, vuie fish, can be added to the aquarium, kept there and fed. ujerden. If, on the other hand, the biological filter is outside the container for breeding the aquatic animals (see, for example, the filter described in US patent application Ser - and temperature range, after which the ammonia source, the bacteria and the iron and copper source are added to the system.

The present invention further relates to a packing of material which is used to reduce the setting of a biological Filters are suitable for the time required. Such

609831/0862

- 19 pack includes:

(a) -a container with a source of ammonium ions, preferably just sufficient to provide about 0.1-5.0 ppm NH ^ ⁺ in the water circulating through the biological filter;

(b) a container with a copper ion source, preferably straight sufficient to provide about 0.1-630 ppm copper in the water circulating through the biological filter; and

(c) a container with a source of copper ions, preferably just enough to create about 1-560 ppm iron in the circulating water.

This packing of materials is particularly suitable for reducing the nitrifying activity of biologicals Filters in closed-loop aquaculture systems, e.g. home aquariums or systems for shrimp breeding, are required Time, and the pack can be tailored for any size system. If the system is small, e.g. a 40-1 home aquarium, then only sufficient sources of ammonia, copper and iron are available to achieve the desired ion concentrations to give in about 40 liters of water. These concentrations are self-evident so that they are not toxic to the aquatic animals used in the aquarium.

The combination pack can only contain one container with the desired Amount of each of the components. The ion sources can contain solids in the form of a soluble salt or a solution of the ionic * sources must be in sufficient concentration to produce the desired value in the aquarium. 3Each ion source can, however also preferably located in a separate container, or

60983 1/0862

the ammonium and copper ion bottles are in the same container, see above that the method preferred according to the invention, i.e. the addition of iron after determining the nitrite, can be relieved.

609831/0862

Claims (1)

- 21 - Pats η ta η s ρ r ü ch β (ij- Improved Method of Adjusting Nitrification Efficiency a biological filter, characterized »that one Water passes through a biological filter medium, the temperature of the water to about 5-35 C. and the pH value of the same sets and maintains at about 7.0-9.0 j an initial set of autotrophic nitrifying bacteria for biological filter medium together with an effective source of ammonia for the autotrophic bacteria, enough soluble copper salt to form a solution of etu / a 0.1-630 ppm copper in the circulating Water and sufficient iron for the formation and iner Lüsutq of adding etu / a 1-560 ppm iron in the circulating water; the water circulates through the biological filter until the concentration of ammonia and nitrite falls below 0.1 ppm; and then the biological filter is used for the desired return. "2 · - method according to claim 1, characterized in that the temperature is kept between etu / a 27-3O ⁰ C, and the pH value between etu / a 8-9, the ammonia in the water in a concentration of 1- 5 ppm, the copper in a concentration of etu / a 0.1-0.3 ppm, the iron in a concentration of etu / a 1.0-2.0 ppm and the biological filter in the l / experienced for water purification used in a closed loop aquaculture system. 60 98 3 1/08 62 3. ~ V / experience according to claim 1 and 2, characterized in that an initial amount of Nitrosomonas and Mitrobacter bacteria is added, the effective amount of ammonia and the copper salt being added to the circulating water before the addition of the iron salt, the water circulates until 0.1 ppm or more nitrite ions can be detected and then the iron adds to the system. 4.- The method according to claim 1 to 3, characterized in that the arr.moniumquelle is added at the same time as the copper source. 5.- V / experience according to claim 1 to 4, characterized in that the ammonia jellyfish ammonium chloride in sufficient.: amount is, around a solution of 0.1 to etiua 5 ppm ammonia in the circulating To yield water. 6.- The method according to claim 1 to 5, characterized in that ammonia source and copper are added to the circulating water the water for at least 3 and not more than 5 days at 27-30 ° C. and a pH between 8.0-9.0 is circulated, before the iron source is added. 7.- V / experience according to claim 2, characterized in that a soluble molybdenum salt is added at the same time as the iron. i-i—— net that water is put into a suitable aqua-food container, Water from this BehalterdLLrjs + r ^ irT biological filter medium and back to the ^ aehÄXter, the temperature of this water circulates retroactively
609831/0862 retroactively -Wr- 13.- The method according to claims ^ J2- _r --d'a "ciürch characterized in that a soluble molybdenum salt is added at the same time to fine iron 14, - A method for adjusting the nitrification activity of a biological filter, characterized in that ^- one (a) passes water through a biological filter medium; (b) the temperature of the water to etu / a 27-30 ° C. and the pH word sets and maintains between 8 and 9; (c) an initial set of autotrophic nitrifying bacteria for biological filter medium together with sufficient ammonium ions for a concentration of about 4-5 ppm and sufficient copper ions add copper ions to the water for a concentration of 0.1-0.2 ppm; (d) the water circulates for at least 3 and not more than 5 days; (e) adds enough iron ions to a concentration of about 1-2 ppm in the water. (f) the water circulates for at least 7 days but not more than 9 days; and (g) used the filter as desired 15.- The method according to claim 14, characterized in that the source of ammonium ions NHaCl, the source of copper ions Copper sulphate, the source of iron ions with ethylenediaminetetraacetic acid is chelated iron and the biological filter used in a closed loop aquaculture system will. 609831/0862 16.- pack for use in the l / experience according to claim 14, containing a Container with an ammonium ion source, a container with a copper ion source and a container with a source of iron ions. 17, - pack according to claim 16, characterized in that the Ammonium ion source ammonium chloride, the copper ion source copper sulfate and the source of iron ions is iron chelated with ethylenediaminetetraacetic acid. 18.- Pack according to claim 16 "and 17, characterized in that the ammonium chloride in the one containing the copper sulfate Container is present; The patent attorney: J) 609831/0862