Organozeolite, A new absorbent for removing harmful anions from recirculating aquaculture effluent

Waste water treatment is important for an economical and environmentally friend aquaculture enterprise. In last 30 years, synthetic and natural zeolites have been increasingly acknowledged due to their capability of removing toxic ions at lower concentrations which are common in aquaculture effluent. Contaminants in aquaculture effluent such as nitrate and nitrate can promote eutrophication of receiving waters and be potentially toxic to aquatic life. 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 zeolite. To this end, zeolite obtained from the Semnan, located in the center of Iran, was modified using tetradecyltrimethylamonium bromide (TDTMA) and exposed to effluent from a fish culturing facility. ANOVA revealed that temperature had a well-arranged effect on nitrate and nitrite removal by modified zeolite compared with pH. Zeolite significantly showed higher nitrate and nitrite removal capacity at 15°C (p<0.05). However, pH had not any significant effects on nitrate removal (p>0.05). However, higher nitrite uptake was observed at pH= 6 and ph=8 (p<0.05). To devise an efficient zeolite based removal filters special for aquaculture effluents, more studies are needed in future.

Keywords:

aquaculture effluent , modified zeolite , nitrate , nitite , TDTMA