Biosorption of chromium by mangrove-derived <i>Aplanochytrium sp.</i>

Abstract

The microbial dried biomass of Thraustochytrids is used as bioadsorbent for the removal of the chromium in aqueous solution. In this investigation, three species of Thraustochydrids namely Aplanochytrium sp., Thraustochytrium sp. and Schizochytrium sp. were tested for the efficiency of chromium accumulation by culturing in chromium-incorporated medium at 30°C for one week incubation. The biomass was harvested by filtration through Whatman no.1 filter paper. The level of metal accumulation in the biomass was determined by using an inductively coupled plasma system (ICP- Optical Emission Spectrophotometer; Optima 2100DV). Finally, among the three strains, Aplanochytrium spp. was selected for the adsorption kinetics and optimization using response surface methodology. Optimization of chromium removal by dried microbial biomass was analyzed with important factors of different pH, adsorbent dosage (Aplanochytrium dried biomass), temperature and processing time with 30 batch experimental plan derived from the centre composite design (CCD) of response surface methodology. Aplanochytrium sp. dried biomass removed chromium of 69.4% in aqueous solution. Therefore, Aplanochytrium sp. dried biomass is potent for the removal of chromium in waste water treatment.

Key words: Mangroves, chromium removal, Aplanochytrium sp., biosorption, waste water treatment.