Dried Seaweed (Sargassum ilicifolium) as an Adsorbent for Phosphorous Removal from Aqueous Solutions

Aquaculture is a source of significantamounts of wastes, which generally leads todeterioration of water quality. Removal ofphosphorous (P) from aquaculture wastewateris an important environmental challenge.In the present study, efficacy of dry sea weed(Sargassum ilicifolium) to remove water P wasinvestigated under laboratory conditions. Severallevels of medium pH (۳.۵-۱۰), initial Pconcentration (۰.۰۱۵-۰.۴۵mgl-۱), contact time(۷-۶۰min), particle size (۰.۵-۵mm) and the seaweed particle concentration (۱۰-۴۰gl-۱) havebeen monitored. The results showed a high efficiencyof the sea weed to remove water P underdifferent conditions (۸۳.۱-۹۷.۷% P removal).Among the tested pH, ۳.۵ had the lowestP removal. P removal linearly increased alongwith time progress. The lowest P removal wasobserved in the lowest initial P concentration(۰.۰۱۵mg/l), however, there was no significantdifference among the groups with initial P concentrationof ۰.۱۵-۰.۴۵ mg/l. P removal in ۱۰g/lsea weed concentration was significantly lowerthan those of ۲۰ and ۴۰g/l. P removal significantlyincreased with decrease in sea weed particlesize. Regression analysis showed that theweight of factors to remove P from the mediumwas as follow: particle size (β = -۰.۶۵۹)> particleconcentration (β = ۰.۴۲۷)> time (β = ۰.۲۲۷)>initial P concentration (β = ۰.۱۹۰)> medium pH(β = ۰.۱۱۳). In conclusion, dry S. ilicifolium iscapable to efficiently remove P from wastewaterat aquaculture-relevant concentration. TheP removal capability of the seaweed markedlyincreases by decrease in particle size and increasein particle concentration in medium.

Keywords:

Uptake , Phosphorus , Wastewater , Seaweed , Adsorption