Modified clay as new absorbent for removal anions from aquaculture recirculation effluent

clays have been increasingly acknowledged due to their capability of removing toxic ions even at lower concentrations which are common in aquaculture effluent. Contaminants in aquaculture effluent such as Phosphate and sulphate can promote eutrophication of receiving waters and be potentially toxic to aquatic life. Natural bentonite can remove cations and heavy metals from wastewater. At the present study the natural bentonite and surfactant modified bentonite (SMB) was characterized using XRD analyses. To remove anions from samples, modification was practiced with tetradecyletrimethyleammoniumbromid (TDTMA) to increase the adsorption of anions which subsequently increases the ion absorption capacity of bentonite per se. These systems are still in their infancy and there is not enough information in this regard. Present study aimed to have more insight into the effects of different ambient pHs (6, 6.5, 7, 7.5 and 8) and temperatures (10, 15 and 20 ?C) on the ion adsorption capability of modified bentonite. Results showed that these parameters affected ion absorption. pH has a prominent effect on the ion adsorption to the extent that increasing pH improves the anion adsorption, about nitrite the best adsorption was at neutral pH (48.128), in the case of nitrate increasing pH cause increase in adsorption. Like pH, temperature has positive effect on ion adsorption. It seems that activated surface layer has better tendency to nitrite anion. Surfactant modified bentonite can be used as a new absorbent for toxic anions from aquaculture wastewater.

کلیدواژه ها:

aquaculture wastewater ، modified bentonite ، organoclay ، Harmful anions surfactant ، TDTMA