The Addition of Different Adsorbents In SA-PVA Matrix For Bacillus Subtilis Immobilization on Methylene Blue Decolorization

Wastewater which is not handled by a proper treatment before released in the water body, can cause damage for aquatic biota and its environment. MB is a synthetic textile dye which is toxic and difficult to degrade. Bioremediation by decolorization using microbes such as bacteria is one of the best methods for dye removal. By immobilizing Bacillus subtilis bacterium in an appropriate matrix, it could have more advantage on dye decolorization than by free cell only. The sodium alginate (SA) and polyvinyl alcohol (PVA) are well known as good matrix for decolorization. Besides the addition of B. subtilis in the SA-PVA matrix, the addition of adsorbents could enhance the decolorization. In this study, different adsorbents: bentonite, activated charcoal, kaolin, and corncob powder were investigated for influencing MB decolorization by immobilized B. subtilis in SA-PVA matrix. The result showed that the highest MB decolorization was reached by SA-PVA-B. subtilis with the presence of activated charcoal by approximately 88% of 100 mg/L, followed by the addition of bentonite (82%), kaolin (80%), and corncob powder (79%). The MB decolorization by SA-PVA-Activated charcoal-B. subtilis reached optimum condition at temperature 35 °C, 24 h incubation time in static condition.