IL106650A - Aqueous medium for treatment and breeding of fish and method for producing said medium - Google Patents

Abstract

Aqueous medium for treatment and breeding of fish characterized by a content of from 0.003 to 0.4 mg active chlorine per liter water and that said aqueous medium has a pH-value of from 4.0 to 8.0 and a redox potential to platinum, relative to Ag/AgCl, of from +150 to +650 mV.

Description

12*20 TOrt HB l a¾7 VlTWl 'ΊΒ'η'Γ JI TO Π3·¾0 Aqueous medium for treatment and breeding fish and method for producing said medium Background of the invention 1 . Field of the invention This invention relates to aqueous medium for reside in fish for breeding, keeping and medical treatment of fish with employing water treated by method of electro-chemical treatment in diaphragm electrolyzer where acolytes fraction of treated water from anode compartment is going out with beforehand goals of pH, redox potential and content of active chlorine . Use of this invention lead to decreasing number of microbes in aqueous medium from 10 7 Col/ml to 103 Col/ml , decreasing Colt-index from 105 Col/ml to 102 Col/ml, decreasing fish mortality 3 fold, decreasing amount of organic and inorganic components in water (ammonia, nitrites, pest's, gerbs etc. ), give increasing in weight of from 30% to 50%. This invention can be exploit both by aquarium at home and at big territories of breeding fish and for big volumes of water. 2. Description of prior art There exist today several methods for medical treatment of fish, where each method works with varying efficiency and gives variable results .

Main method, used today in medical treatment of fish is administering the active agent orally or parenterally or by bathing, washing or breading the fish in aqueous solution, containing the active agent, which may be therapeutic and aqua-cultural chemical, remedies or vaccine / See US Patent 4. 1 10.467 Int. C 1 . A6 1 K31 /335 . 1978/. But these methods have many restrictions. Most therapeutics for fish are potentially toxic / Fish diseases . Refreshed course for veterinarian. Proceeding 106. University of Sidney . 1988/, if used for too long or of too high a dose rate, if they deplete oxygen, or if the treated fish are more susceptible to size, age, species, or current diseases including the disease at which the treatment is aimed. Treatments such as formalin baths usually kill some of the treated fish and the weaker the fish are the more will die from the treatment rather than the disease.

S ome particular cautions are noteworthy. Formalin, used against ectoparasites, depletes oxygen and should only be used with attention to water oxygen levels, including the use of aeration. Benzalkalonium chloride used in environmental gill disease is especially toxic in soft water and for salmonid fry and lightly scales or scalesess species such as eel, loach, galaxid and plotosid and ictalured catfishes. Malachite green is also highly toxic to fry and scalesess species. The parasiticide potassium permanganate, although it generates rather than depletes oxygen, has a therapeutic index below 5 , is more toxic for scalesess or lightly scales species , and its active concentration varies greatly with organic content of the water, making the attainment of effective and safe levels difficult. Copper also has a critically low therapeutic index of about 3 , its active concentration varies with water hardness, and it should only be used with careful monitoring of the dissolved concentration.

Certain therapeutic chemicals^ ^including methylene blue, potassium permanganate, erythromycin, chloramphenicol and, to a lesser extent, nifurpirinol and formalin inhibit the nitrifying bacteria essential to ammonia and nitrite detoxification in aquarium biofilters . It is probable that a large proportion of treatment failures reported by aquarium owners to end in death are, sadly, due to progressive nitrite toxicity induced by the treatment, particularly methylene blue which is present in most proprietary " cure-all " mixtures, rather than the initial disease.

S everal additional chemicals employed in aquacultural units can cause serious mortality. The algicides copper sulfate and simazine are examples, as are phenol based disinfectants which are deceptively persistent in water and on nets, boots and other equipment. An area of particular concern is the use of organo-tin antifoul compounds which are neurotoxic and heptotoxic, on fish-holding net cages and boats. Tri-n-butyl tin (TBT) is acutely toxic to juvenile, salmonids at 1 .5 to 20 mg/ 1 and fish accumulate tin to levels as high as 7mg/kg in liver and Img/kg in muscle before death after acute or chronic exposure, thus posing an additional consumer health risk. High mortality of juvenile net-pen reared salmonids have thus been attributed to the us of TBT antifoul on the netting. Mollusces also bioaccumulate organo-tin from boat antifouls, prompting British authorities to nominate a maximum environmental level of 20ng/l . Copper, nickel and other antifouling agents are also of concern.

S econd method - it is physic treatment of water (ozone, ultraviolet light etc. ).

Ozone has been found useful in a number of application related to human activities because of its high oxidation potential. Ozone is used for drinking water sterilization and swimming pool water treatment as well as a sublemental treatment agent at municipal waste water units. Disinfection by ozonation is most efficiently achieved in already pretreated water. The disinfection of waste water requires more ozone because of the demand created by the other materials present which complete for the ozone. (3 )/Harald Rosental. Symposium on new development in the utilization of heated effluents and of recirculating systems for intensive aquaculture. Stavanger. Norway. 28-30 May 1 980./. Also ozonation has insignificant or no residual disinfection capacity and water sterilization by ozonation is not at all consistent even is constant ozone doses ant contact times are maintained the reason are manifold.

Ultraviolet light has largely been applied for water sterilization in public aquaria and oyster and fish hatcheries . Ultraviolet radiation is able to pass through high quality distilled water to considerable depth, but dissolved substances and suspended materials (turbidity), whether organic or mineral , can greatly reduce penetration. Effectiveness of UV treatment depends also on cooling of the surface of the tube, time's operation of the tubes etc.

It is known disinfection of water by electro-chemical treatment (4)/Disinfection of water by electro-chemical treatment. G. Patermarakis and E. Fountoukidis . Wat. Res . Vol.24. Nol2. Ppl491 - 1496. 1990. Pergamon Press pec . G . B . /. The main advantage of the electro-chemical process of disinfection is the production of disinfective chemicals in the treatment device, i . e. the production of chlorine by electrolyzing a mixture of sewage with seawater, thus avoiding the drawbacks of common chlorination such as transport and storage of dangerous chlorine. The electro-chemical treatment of water has also purification process for the removal of ionic, impurities such as sulfates, phosphates, chlorides , heavy metals cationes such as copper, mercury, lead, iron and organic compounds . Electro-chemical treatment also decreases turbidity and improves the taste and odour of water. Electro-chemical treatment of water can destroy a large variety of microorganisms . Approximately 40 species of microorganisms varying in size from viruses through bacteria and algae to relatively large species such as Englena have been successfully treated.

Summary of the invention In the fi sh breeding, keeping and medical treatment parazites, microbes, viruses (fish diseases) and pollutants can be a great nuisance and create great loses . All chemotherapeutic agents are toxic to fish -successful treatment is only obtained by treading a fine line between safety and disaster. Physics methods are also rather dangerous, difficult and cannot be used to big amount of water.

Water quality, is probably, the must important factor in maintaining fish health . The purpose of present invention is to prevent fish's loses by using aqueous medium for treatment and breeding fish characterized by content of from 0.003 to 0.4 mg. active chlorine per liter water and at said aqueous medium have pH-value of from 4.0 to 8.0 and a redox potential to platinum, relative to Ag/AgCl, of from + 1 50 to +650 mV.

Producing such aqueous medium is achieved by water's treatment with method of electro-chemical treatment in diaphragme electrolyzer with anode and cathode compartment where anolyte fraction of treated water from anode compartment is going out with beforehand goals of pH, redox potential and content of active chlorine.

Here is also opportunity to use portion of water or aqueous medium treated up to value of pH, redox potential and content of active chlorine with exceed value of mentioned above and to mix this portion of water or aqueous medium with residual aqueous medium and at that mentioned portion of water or aqueous medium is treated to such values of parameters pH, redox potential and content of active chlorine, which ensure parameters of aqueous medium after mixing as said above.

To producing above said aqueous medium here is giving two examples of devices. The first include two diaphragme electrolyzer with anode and cathode compartment, rectifier for supply above mentioned electrolyzers with direct current, system of electromagnetic valves for changing water's flow from exit of electrolyzer by such manner, that by one circuit water's flow from above mentioned anode compartment of first electrolyzer was running to tanks with fish and from anode compartment of second electrolyzer was running to cleaning above mentioned cathode compartment of first electrolyzer and in second circuit this two above mentioned are changing their direction and in this case water's flow from anode compartment of first electrolyzer will be running to cleaning cathode compartment of second electrolyzer and water's flow from anode compartment of second electrolyzer will be running to the tanks with fish, timer to periodically switching this system of electromagnetic valves, controller to measure redox potential in tanks with fish and switching the rectifier.

Brief description of the drawings Fig. l - scheme of device with two electrolyzer Fig.2 - scheme of device with one electrolyzer Fig.3 - a count of microbes in aqueous medium (Test Txl and Tx2) and in untreated water (Control) Fig.4 - a Coli-index in aqueous medium (Test Txl and Tx2 ) and in untreated water (Control) Fig.5 - total mortality in aqueous medium (Test Txl and Tx2) and in untreated water (Control) and influence of water's treatment on fish growth .

Detailed description of the preferred embodiment The invention is based on disinfection properties of aqueous medium produced by method of electro-chemical treatment of water in diaphragm electrolyzer with anode and cathode compartment where the anolyte fraction of treated water (aqueous medium) from anode compartment is going out with beforehand goals of pH, redox potential and content of active chlorine in next limits : - content of from 0.003 to 0.4 mg active chlorine per liter water - pH-value of from 4.0 to 8.0 -redox potential to platinum, relative to Ag/AgCl, of from + 1 50mV to +650mV Aside from disinfection properties such aqueous medium has also excess charge of energy which produced promotional (stimulation) effect on the fish. Joint action of two effects (disinfection and stimulation) lead to decreasing number of microbes in aqueous medium from 1 07 Col/ml to 103 Col/ml, decreasing Coli-index from 105 Col/ml to 102 Col/ml, decreasing fish mortality 3 fold, decreasing amount of organic and inorganic components (ammonia, nitrites, pest's, gerbs etc. ) give increase in weight of fish from 30% to 50%. This invention can be exploit both by aquariums at home and at big territories of breeding fish and for big volumes of water.

In my opinion and observation only such aqueous medium influence on fish as medical treatment and stimulation as since it has at the same time disinfectiv and promotional effect. By using chemical additions to water to achieve the same result as said above as a rule lead to mortality of fish and by using low concentration of chemical additions is absent disinfection effect. Promotional effect is absent by any concentration of chemical additions.

For producing aqueous medium according Claim 1 my be use present diaphragm electrolyzers .

Fig. l is showing the scheme of device with two electrolyzer. Such construction give periodical washing from cathode compartment by the anolyte, what is necessary for permanent work of electrolyzer, the salts of Mg and Ca fill out on the cathode and full volume of cathode compartment.

The device is working as following. Water entrances from feeding line to two electrolyzers 1 and 2 to anode compartment 3 and cathode compartment 4 and exit in system from electromagnetic valves 5, where the water from anode compartment of electrolyzer 1 at one circuit is The controller 8 and sensor 9 of controller are measuring all time the amount of active chlorine and redox potential in tank with fish 10 and according to given program for maintaining these parameters switches on or off the rectifier. running to tank with fish 10 and water from anode compartment 3 of electrolyzer 2 is running to cathode compartment 4 of electrolyzer 1 and water from cathode compartment 4 both electrolyzers is running to sewerage and at the next circuit the water from anode compartment 3 of electrolyzer2 is running to tank with fish 10 and water from anode compartment 3 of electrolyzer 1 is running to cathode compartment 4 of electrolyzer 2 and water from both cathode compartments 4 is running to sewerage. Time and frequency of switching of electromagnetic valves are determined by timer 6. The electrolyzers 1 and 2 are supplied with direct current from rectifier 7. The controller 8 and sensor 9 of the controller are measuring all time the amount of active chlorine and redox potential in tank with fish 10 and according to given program for maintaining these parameters on or off the rectifier.

On the fig 2 is given the scheme of device with one electrolyzer Such construction permits to take off hard salts from cathode compartment due to poles switching of direct current given to anode and cathode, as result of which anode compartment become cathode and vice versa On fig 3 ,4 and 5 are given results of experiments with electrochemicaly treated water according to the above described method which were made at fish breeding station of kibbutz Maagan Michael in April - July of 1 993 On fig 3 is given total count (Col/ml) microbes in water in control tank (untreated water) and in the experimental tanks TX l and TX2 (treated water - aqueous medium) On fig 4 is given count of Coil-form (Col/ml) in water in control tank (untreated water) and in the experimental tanks Txl and TX2 (treated water - aqueous medium) On fig 5 is given total mortality of fish in the control tank (untreated water) and in the experimental tanks TXl and TX2 (treated water - aqueous medium) and average weight of fish at beginning of experiment and after three month in control tank and experimental tanks At beginning of experiment in each tank (one - control and two-experimental) was at 350 fish

Claims (4)

10 106650/2 Claims

1. . Aqueous medium for treatment and breeding fish characterized by content of from 0.003 to 0.4 mg active chlorine per liter water and at said aqueous medium has pH-value of from 4.0 to 8.0 and a redox potential to platinum, relative to Ag/AgCl, of from + 1 50 to +650 mV.

2. Method of producing aqueous medium according to claim 1 for treatment and breeding fish at that water treated by method of elecrtochemical treatment in diaphragm electrolyzer with anode and cathode compartment where anolyte fraction of treated water from anode compartment is going out with beforehand goals of pH, redox potential and content of active chlorine.

3. Method according to claim 2, characterized in that portion of water or aqueous medium treated up to value of pH , redox potential and content of active chlorine which exceed value indicated in claim 1 and this portion of water or aqueous medium is mixed with residual aqueous medium and at that mentioned portion of water or aqueous medium is treated to such values of parameters pH, redox potential and content of active chlorine which ensure parameters of aqueous medium after mixing according to claim 1 .

4. Method according to claim 1 or 2 , as described above, with reference to enclosed specification.