CN1336114A

CN1336114A - Disinfectant for culture of fishery

Info

Publication number: CN1336114A
Application number: CN 00115919
Authority: CN
Inventors: 严幼宽; 刘华祥
Original assignee: Individual
Current assignee: Individual
Priority date: 2000-07-31
Filing date: 2000-07-31
Publication date: 2002-02-20

Abstract

An antiseptic for aquaculture is prepared from sodium dichloroisocyanuriate, sodium bromide, sodium sulfate, carboxymethylcellulose sodium through grounding, mixing, micronencapsulating, drying to obtain product, said antiseptic can effectively kill algae, virus, bacteria and protozoon. The cyanaric acid that is produced after releasing chlorine from sodium dichloroisocyanuriate can be easily decomposed by the enzyme of organisms, so that no residual poison is left.

Description

Disinfectant for aquaculture

The invention relates to a disinfectant for aquaculture industry.

The disinfectants used earlier in the aquaculture industry and still more adopted to date are sodium hypochlorite, bleaching powder and trichloroisocyanuric acid (commonly called strong chlorine). The former three have unstable chlorine, easy loss and short storage period. The latter is also very unstable, smells heavy, is also very corrosive, unsafe, and has low solubility and inconvenient use, thus the application range is limited.

The disinfectant widely used internationally at present is sodium dichloroisocyanurate which is officially approved by the national food and drug administration and the environmental protection administration to be applied to food and drinking water due to high efficiency and mildness, but does not act on algae, thereby limiting the application of the disinfectant in the aquaculture industry. After that, a new disinfectant, bromochlorodimethylhydantoin, appears, which has the effect of killing fungi, bacteria and the like, but has residual toxicity because the solubility is low, and the product dimethylhydantoin after releasing chlorine and bromine is not easy to be completely degraded by organisms.

The invention aims to solve the problems that sodium dichloroisocyanurate is ineffective to algae and bromochlorodimethyl hydantoin has residual toxicity, and aims to provide a disinfectant for aquaculture industry, which can effectively kill algae, viruses, bacteria and protozoa and has no residual toxicity.

The disinfectant for aquaculture industry is a powdery mixture of 9.64-10.0% of sodium dichloroisocyanurate, 9.07-9.32% of sodium bromide, 60.23-61.09% of sodium sulfate and 15.09-15.20% of sodium carboxymethylcellulose by weight, and is externally provided with 5.11-5.25% of microencapsulation, wherein the content of effective chlorine and bromine in the disinfectant is 5.2-5.6% and 6.59-6.80% respectively.

The sodium dichloroisocyanurate selected by the invention has good stability, the storage period can reach two years, and the loss is 1% under the condition of normal-temperature storage. The preparation method comprises the following steps:

the sodium bromide is a product obtained by reacting hydrobromic acid with NaCl and NaOH and then drying.

The invention respectively crushes, screens and proportionally mixes the four raw materials of sodium dichloroisocyanurate, sodium bromide, sodium sulfate and sodium carboxymethylcellulose, adds microcapsule microcapsules by a common microencapsulation method, and then dries the microcapsules in an oven at 60 ℃ for 4 hours to obtain the product.

The disinfectant has good stability, and is convenient for storage and transportation. The stability test is carried out at the epidemic prevention station in Wuhan City, and the test method and the result are as follows:

materials: 0.01024mol/L sodium thiosulfate standard solution, 2mol/L sulfuric acid solution, 10% potassium iodide solution and 0.3% starch.

The method comprises the following steps: according to Disinfection Specification 1991.12 of Ministry of health.

And (3) placing the three packaged samples into a 54 ℃ water-soluble box for 14 days, taking out the samples to measure the available chlorine content, comparing the results with those before placement, calculating the reduction rate, repeating the test for three times, and averaging the results. The results are shown in Table 1.

TABLE 1

Disinfectant	Content of effective components before placement (％)	Content of effective components after standing (％)	Rate of decline (％)
Disinfectant	Content of effective components before placement (％)	Content of effective components after standing (％)	Rate of decline (％)	Number 1 Number 2 No. 3	92.13 95.25 94.21	88.31 91.15 90.13	4.14 4.30 4.34
Average	-	-	4.26	Number 1 Number 2 No. 3	92.13 95.25 94.21	88.31 91.15 90.13	4.14 4.30 4.34

The results of quantitative sterilization tests conducted in the epidemic prevention station of Wuhan City with reference to "Disinfection technical Specification" 1991.12 of Ministry of health are shown in Table 2.

TABLE 2 Sterilization of disinfectantA (5min)

Concentration of	Bacterial strain	Test bacteria concentration (one/ml)	The sterilization rate%
Concentration of	Bacterial strain	Test bacteria concentration (one/ml)	The sterilization rate%	1∶10000 1∶20000 1∶40000	Staphylococcus aureus	2×10⁷	100
1∶1000 1∶20000 1∶40000	Escherichia coli	32×10⁷	100	1∶10000 1∶20000 1∶40000	Staphylococcus aureus	2×10⁷	100
1∶1000 1∶20000 1∶40000	Escherichia coli	32×10⁷	100	1∶10000 1∶20000 1∶40000	Bacillus subtilis	24×10⁷	100

As can be seen from the table, the disinfectant can effectively kill viruses, bacteria and other harmful substances.

The toxicity test is carried out by intragastrically irrigating mice according to different doses, and the test method and the results are as follows:

experimental animals: 18-22 g of 100 healthy Kunming mice.

The experimental method comprises the following steps: a probabilistic unit method. Animals were randomly assigned to five dose groups of 10 animals per group, each group corresponding to test articles 1000, 850, 720, 610, 520ml/kg body weight, by sex after 16 hours of fasting. Each dose to be tested is prepared by adding 15% of Arabic gum into a test substance, and is orally administered once in a gavage volume of 20ml/kg body weight. One week post test observation.

The experimental results are as follows: animals with each dose showed symptoms of flaccidity, unstable gait, etc. 30 minutes after gavage, and death occurred within 48 hours. The rest mice gradually recovered to normal.

Mouse death number and LD50 value thereof

Dosage form (mg/kg)	Number of dead animals/number of experimental animals Male and female	LD50 value and 96% confidence limit (g/kg) Male and female
Dosage form (mg/kg)		LD50 value and 96% confidence limit (g/kg) Male and female	1000 850 720 610 520	10/10 10/10 8/10 8/10 7/10 7/10 1/10 2/10 0/10 0/10	687 676 (759～622) (740～618)

The test result shows that the disinfectant is nontoxic in a proper dosage range and does not poison fish and shrimp aquatic products.

The disinfectant combines sodium dichloroisocyanurate and sodium bromide, overcomes the defects that the sodium dichloroisocyanurate is ineffective to algae, and bromochlorodimethylhydantoin is not easy to be completely degraded by organisms to cause residual toxicity, can effectively kill algae, viruses, bacteria and protozoa, and cyanuric acid after the sodium dichloroisocyanurate releases chlorine can be degraded by enzymes of various organisms without residual toxicity remaining.

The disinfectant is tried in 13 shrimp ponds with the area of about ten mu in the north sea in 4-6 months in the year, the shrimp pond using the disinfectant has the per mu yield of 80-100kg of prawns, and a contrastshrimp pond without the disinfectant causes a great amount of death, some death and even complete death of the prawns due to the shrimp diseases such as leukoderma and the like, thereby causing the failure of harvest.

The disinfectant has simple production process, convenient use, stable performance, convenient storage and transportation, low toxicity, safety and no pollution to the environment, and provides an effective preparation capable of ensuring harvest for shrimp citizens.

Claims

1. The disinfectant for aquaculture is a powdery mixture of 9.64-10.0% of sodium dichloroisocyanurate, 9.07-9.32% of sodium bromide, 60.23-61.09% of sodium sulfate and 15.09-15.20% of sodium carboxymethylcellulose by weight, and is externally provided with 5.11-5.25% of microencapsulation, wherein the content of effective chlorine and bromine in the disinfectant are respectively 5.2-5.6% and 6.59-6.80%.