University of Tehran Journal of Environmental Studies 1025-8620 38 1 2012 05 21 Application of Modified Bentonites (SMB and ATB) for Decreasing the Environmental Effects of Phosphate and Sulphate Anions Existing in RAS Application of Modified Bentonites (SMB and ATB) for Decreasing the Environmental Effects of Phosphate and Sulphate Anions Existing in RAS 31 40 29009 10.22059/jes.2012.29009 FA Zoheir Shokouh Saljoghi Gholamreza Rafiee Akbar Malekpour Amir Shokouh Saljooghi Omid Safari Journal Article 1970 01 01 Use of wastewater treatment methods in aquaculture is one of the main ways for decreasing the environmental effects of this industry and applies the Best Management Practices (BMPs). Anionic compounds are the main pollutants in recirculation aquaculture systems. Ion exchangers such as clays are vastly applied in waste water industry but in Aquaculture systems at yet there isn't any report about use of this materials. Negative surface of the clays enable them for adsorbing cations, however, they do not have any tendency for absorbing anions. Meanwhile, by modifying surface structure, they can adsorb 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 adsorb the 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 effected anionic adsorption. Phosphate adsorption from aquaculture effluent and standard solution by two absorbent had significant affected by ambient temperature (P< 0.05), While sulphate adsorption by two adsorbent didn't showe increasing trend. In aquaculture effluent, pH didn't 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 adsorption from recirculation aquaculture system. Use of wastewater treatment methods in aquaculture is one of the main ways for decreasing the environmental effects of this industry and applies the Best Management Practices (BMPs). Anionic compounds are the main pollutants in recirculation aquaculture systems. Ion exchangers such as clays are vastly applied in waste water industry but in Aquaculture systems at yet there isn't any report about use of this materials. Negative surface of the clays enable them for adsorbing cations, however, they do not have any tendency for absorbing anions. Meanwhile, by modifying surface structure, they can adsorb 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 adsorb the 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 effected anionic adsorption. Phosphate adsorption from aquaculture effluent and standard solution by two absorbent had significant affected by ambient temperature (P< 0.05), While sulphate adsorption by two adsorbent didn't showe increasing trend. In aquaculture effluent, pH didn't 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 adsorption from recirculation aquaculture system. https://jes.ut.ac.ir/article_29009_b170fdd5e02251a9f3fc22fe4c6c624b.pdf