جستجوی مقالات مرتبط با کلیدواژه "surfactant" در نشریات گروه "شیلات"

Anionic detergents make up a large portion of domestic wastewater due to their high consumption. With the entry of wastewater into water sources, these substances enter the aquatic environment and cause serious damage to aquatic animals, including fish, by reducing dissolved oxygen in water and causing stress. The aim of this study was to obtain evidence to determine the effect of these substances on the embryonic growth of rainbow trout. For this purpose, rainbow trout eggs and embryos were exposed to doses of 1 mg / l of washing powder, 0.5 mg / l of dishwashing liquid, 0.25 mg of bleach in different stages from fertilization to hatching and sampling was done during this period. The treatments were tested for embryonic growth time, percentage of eyeing, percentage of mortality, appearance and cortisol levels of eggs and embryos. The results showed that detergents accelerate the stages of embryonic development, increase the mortality rate, reduce the percentage of eyeing, induce stress and increase cortisol and cause fetal abnormalities. In general, it can be concluded that the entry of domestic and industrial wastewater and subsequently entry of detergents into water sources can cause toxic effects and irreparable damage to aquatic species

Nitrogenous compounds are the main anionic pollutants in recirculating aquaculture systems. Ion exchangers are vastly applied in waste water industry. Negative surface charge? of the zeolites and clays enable them for cation absorptions, however, they do not have any tendency for absorbing anion absorptions. Meanwhile, by modifying surface structure??, they can absorb anions. In the present study, modifications of superficial and layered structures of clays were carried out using the organic compound, tetradecyltrimethylammonium and heat treatment to enable the ion exchangers to absorb the nitrogenous anions from rearing system. Three different ambient temperatures (10, 15 and 20 °C) and different pHs (6, 6.5, 7, 7.5 and 8) were used. Results showed that environmental conditions influenced anionic adsorption. Nitrate and nitrite absorption from aquaculture effluent and nitrate from standard solution by two absorbent had significant effect by ambient temperature (P< 0.05). In aquaculture effluent, pH did not show any regular effect on nitrite absorption. It was inferred that environmental factors such as temperature, pH, anion concentration, presence of other ions and counter ions are effective on absorptive capability of a given ion. Results showed that modified ion exchangers might be useful for harmful anion absorption from recirculating aquaculture system.