THE EFFECT OF TOXIC SUBSTANCES ON THE DEVELOPMENT OF DISEASES IN AQUATIC ORGANISMS

2010 ◽  
Author(s):  
BRIAN AUSTIN
Keyword(s):  
Aquatic Organisms ◽  
Toxic Substances

scholarly journals Denitrification Control in a Recirculating Aquaculture System—A Simulation Study

Processes ◽  
2020 ◽  
Vol 8 (10) ◽  
pp. 1306
Author(s):  
Pedro Almeida ◽  
Laurent Dewasme ◽  
Alain Vande Wouwer
Keyword(s):  
Carbon Source ◽  
Carbon Sources ◽  
Aquatic Organisms ◽  
Operating Conditions ◽  
Toxic Substances ◽  
Recirculating Aquaculture System ◽  
Treatment Technology ◽  
Tuning Method ◽  
Recirculating Aquaculture ◽  
Aquaculture System

The recirculating aquaculture system (RAS) is a land-based water treatment technology, which allows for farming aquatic organisms, such as fish, by reusing the water in the production (often less than 5%). This technology is based on the use of filters, either mechanical or biological, and can, in principle, be used for any species grown in aquaculture. Due to the low recirculation rate, ammonia accumulates in the system and must be converted into nitrate using nitrification reactors. Although less toxic for fish, nitrate can also be further reduced into nitrogen gas by the use of denitrification biofilters which may create several issues, such as incomplete denitrification, resulting in toxic substances, such as nitrite and nitric oxide, or a waste of carbon source in excess. Control of the added quantity of carbon source in the denitrification biofilter is then mandatory to keep nitrate/nitrite concentrations under toxic levels for fish and in accordance with local effluent regulations, and to reduce costs related to wasted organic carbon sources. This study therefore investigates the application of different control methodologies to a denitrification reactor in a RAS. To this end, a numerical simulator is built to predict the RAS behavior and to allow for the comparison of different control approaches, in the presence of changes in the operating conditions, such as fish density and biofilter removal efficiency. First, a classical proportional-integral-derivative (PID) controller was designed, based on an SIMC tuning method depending on the amount of ammonia excreted by fish. Then, linearizing and cascade controllers were considered as possible alternatives.

scholarly journals A comparative study of the acute toxicity of the herbicide atrazine to cladocerans Daphnia magna, Ceriodaphnia silvestrii and Macrothrix flabelligera

2014 ◽  
Vol 26 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Raquel Aparecida Moreira ◽  
Adrislaine da Silva Mansano ◽  
Lidiane Cristina da Silva ◽  
Odete Rocha
Keyword(s):  
Acute Toxicity ◽  
Daphnia Magna ◽  
Native Species ◽  
Aquatic Organisms ◽  
Toxicity Tests ◽  
Toxic Substances ◽  
Tropical Freshwaters ◽  
Test Organisms ◽  
Herbicide Atrazine ◽  
Acute Toxicity Tests

AIM: In this study we compared the sensitivity of three species of Cladocera, Daphnia magna, Ceriodaphnia silvestrii and Macrothrix flabelligera, to the commercial product of the herbicide Atrazine, the Atrazine Atanor 50 SC® (500 g/L), widely used on crops in Brazil. METHODS: Acute toxicity tests were performed at the nominal atrazine concentrations 2.25, 4.5, 9.0, 18.0, 36 and 72 mg L-1, on C. silvestrii and M. flabelligera and at 2.25, 4.5, 9.0, 18.0, 36, 72 and 144 mg L-1 on D. magna. The range of concentrations tested was established in a series of preliminary tests. RESULTS: The toxicity tests showed that the two species naturally occurring in water bodies in Brazil were more susceptible than Daphnia magna. The effective concentrations of Atrazine Atanor 50 SC® (EC50- 48 h) to the species M. flabelligera, C. silvestrii and D. magna were 12.37 ± 2.67 mg L-1, 14.30 ± 1.55 mg L-1 and 50.41 ± 2.64 mg L-1, respectively. Furthermore, when EC50 observed here for M. flabelligera and C. silvestrii were compared with published values of EC50 or LC50 (mg L-1) for various aquatic organisms exposed to atrazine, it was seen that these two cladocerans were the most sensitive to the herbicide. CONCLUSIONS: Considering these results and the broad distribution of C. silvestrii and M. flabelligera in tropical and subtropical regions, it is concluded that these native species would be valuable test organisms in ecotoxicological tests, for the monitoring of toxic substances in tropical freshwaters.

scholarly journals Potentially Toxic Substances and Associated Risks in Soils Affected by Wildfires: A Review

Toxics ◽  
2022 ◽  
Vol 10 (1) ◽  
pp. 31
Author(s):  
Maria Luisa Fernandez-Marcos
Keyword(s):  
Current Knowledge ◽  
Aquatic Organisms ◽  
Water Bodies ◽  
Toxic Substances ◽  
Soil Organisms ◽  
Inhibitory Effects ◽  
Polycyclic Aromatic ◽  
Total Concentrations ◽  
Soil And Water

The presence of toxic substances is one of the major causes of degradation of soil quality. Wildfires, besides affecting various chemical, physical, and biological soil properties, produce a mixture of potentially toxic substances which can reach the soil and water bodies and cause harm to these media. This review intends to summarise the current knowledge on the generation by wildfires of potentially toxic substances, their effects on soil organisms, and other associated risks, addressing the effects of fire on metal mobilisation, the pyrolytic production of potentially toxic compounds, and the detoxifying effect of charcoal. Numerous studies ascertained inhibitory effects of ash on seed germination and seedling growth as well as its toxicity to soil and aquatic organisms. Abundant publications addressed the mobilisation of heavy metals and trace elements by fire, including analyses of total concentrations, speciation, availability, and risk of exportation to water bodies. Many publications studied the presence of polycyclic aromatic hydrocarbons (PAH) and other organic pollutants in soils after fire, their composition, decline over time, the risk of contamination of surface and ground waters, and their toxicity to plants, soil, and water organisms. Finally, the review addresses the possible detoxifying role of charcoal in soils affected by fire.

scholarly journals Utilization of Industrial Effluent for Irrigation - Pros and Cons

2015 ◽  
Vol 37 ◽  
pp. 78-81
Author(s):  
S. David Noel ◽  
M.R. Rajan
Keyword(s):  
Water Level ◽  
Human Health ◽  
Surface Waters ◽  
Technological Development ◽  
Industrial Effluent ◽  
Aquatic Organisms ◽  
Toxic Substances ◽  
Global Issue ◽  
Pros And Cons ◽  
Alternative Sources

Decreasing water level and shortage of water is being a major problem worldwide. For agriculture purpose this problem gives rise to the use of alternative sources of water. Most of these water sources are affected by the discharge waste of effluent from various types of industries like mining, textiles, chemical etc. Due to reason this effluent may contains many organic toxic substances that could have hazardous impact on human health. In addition, technological development has contributed to increase other industrial dumping that contaminates surface waters. The irregular disposal of industrial effluent has created pollution problems since this effluent is disseminated in the environment or is accumulated in sediments, aquatic organisms, and water. In this paper a solution for this global issue has been addressed and strategies have been suggested for this problem.

Development of reference materials with the composition of propyl and isopropyl alcohol solutions

2020 ◽  
pp. 66-72
Author(s):  
Irina A. Piterskikh ◽  
Svetlana V. Vikhrova ◽  
Nina G. Kovaleva ◽  
Tatyana O. Barynskaya
Keyword(s):  
Reference Materials ◽  
Measurement Errors ◽  
Isopropyl Alcohol ◽  
Certified Reference Materials ◽  
Toxic Substances ◽  
Biological Objects ◽  
Margin Of Error ◽  
Measurement Results ◽  
And Control ◽  
Characteristic Mass

Certified reference materials (CRM) composed of propyl (11383-2019) and isopropyl (11384-2019) alcohols solutions were created for validation of measurement procedures and control of measurement errors of measurement results of mass concentrations of toxic substances (alcohol) in biological objects (urine, blood) and water. Two ways of establishing the value of the certified characteristic – mass consentration of propanol-1 or propanol-2 have been studied. The results obtained by the preparation procedure and comparison with the standard are the same within the margin of error.

Vaccines for aquaculture overview

2020 ◽  
pp. 42-43
Author(s):  
Andrey S. Khishov ◽  
◽  
Galina I. Burlakova ◽  
Keyword(s):  
Antimicrobial Agents ◽  
Aquatic Organisms ◽  
Animal Husbandry ◽  
Well Being ◽  
Pharmaceutical Drugs ◽  
Short Development Time ◽  
The Creation ◽  
Basic And Applied Research ◽  
North And South America ◽  
Aquaculture Production

Aquaculture production is a promising direction for the development of food production. Like traditional types of animal husbandry, it needs effective medicines for veterinary use, which would ensure not only the well-being of farmed aquatic organisms, but also increase the safety of the fish products and non-fish objects of fishing. The development of measures to control epizootic processes in aquatic organisms is impossible without the creation of new immunological preparations. The development and use of immunobiological drugs will reduce the use of antimicrobial agents. The corresponding set of pharmaceutical drugs was transferred from the traditional veterinary medicine, but due to the peculiarities of the biology of aquatic animals, their immunity and the characteristics of specific pathogens, this could not be done with biological products. The short development time in the aquaculture industry poses current challenges in the form of a lack of basic and applied research for relatively poorly understood groups of new pathogens. The immunological processes associated with the development and intensity of the immune response in aquatic organisms require a detailed study. For domestic aquaculture producers, the analysis and dissemination of the experience accumulated by mankind and the application of advanced developments in this area are even more relevant, since Russia is just beginning its path of intensifying aquaculture production. At the same time, it is clear that the prohibition of the use and monitoring of antimicrobial agents in food products and feed requires a change in the approach to the problem and will lead to the creation of new immunobiological drugs. The market for immunobiological preparations for aquaculture is the most promising for development. In the article, the authors provide data on the development and registration of vaccines for aquaculture in Europe, North and South America.

Toxic Substances in Crop Plants

1991 ◽  
Author(s):  
J. P. F. D'Mello ◽  
Carol M. Duffus ◽  
John H. Duffus
Keyword(s):  
Crop Plants ◽  
Toxic Substances
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