Ammonia Removal in Baitfish Retail Tanks and on-Farm Flow-through Grading/Holding Vats

Ammonia Removal in Baitfish Retail Tanks and On-Farm Flow-through Grading/Holding Vats

Pejman Ahmadiannamini¹, Satchithanandam Eswaranandam¹, Martin Christie², Ranil Wickramasinghe², Xianghong Qian¹

¹Biomedical Engineering, University of Arkansas, Fayetteville, AR

²Chemical Engineering, University of Arkansas, Fayetteville, AR

Ammonia is the major metabolite of proteins for fish. Zeolite 13X is a promising adsorbent materials with high ion exchange capacity for ammonia removal in fishery water. However, the major concern is that zeolite particles will tend to degrade in water. Moreover, other ions and elements tend to leak into the solution preventing zeolite 13X as an effective adsorbent for ammonium removal in fishery water. In order to overcome the limitation of the direct adsorption approach, zeolite particles were incorporated within polymeric matrices in three different conformations, namely mixed matrix membranes; composite fibers; and pore-filled membranes.

Polymeric composite membranes were prepared via wet phase inversion processes by incorporating zeolite 13X particles into polysulfone matrices formed with and without PEG as a molecular porogen. With increasing zeolite content in the casting solution, the flux was decreased and the removal capacity was enhanced. Adding PEG in the casting solution resulted formation of more porous membranes with higher flux and lower of ammonium removal capacity. Similar solutions were also employed to spin composite fibers. It was found that employing PEG in spinning solutions resulted in lower ammonia removal capacities. Moreover, increasing zeolite and polymer contents resulted in increase and decrease of ammonia removal capacity of fibers, respectively.

Finally, zeolite pore-filled membranes were prepared via filtration of Zeolite 13X suspensions through flipped membranes in order to trap the zeolite powders within macrovoids of the membranes. To prevent particles shedding, the membranes were capped via interfacial polymerization method using an aqueous solution of piperazine and a solution of trimesoyle chloride in n-hexane. Higher zeolite particles were incorporated via pore-filled membranes compared to the mixed matrix membranes.Inductively coupled plasma mass spectrometry (ICP-MS) analysis showed no evidence of ion leakage into water treated by prepared zeolite 13X-polysulfone composite materials.

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Schematic representation of zeolite 13X-polysulfone composite membranes: (A) mixed matrix membrane; (B) pore-filled membrane