Desorption Study of a Fungal Natural Isolate of Aspergillus Sp. in Decolorization of Biomethanated Effluent
In sugar manufacturing, during separation of sugar moiety from non sugar, sugar itself is subjected to number of shocks of alkali, acid and heat. These shocks are actually responsible for formation of sugar decomposition color. The coloring matter produced during sugar manufacturing is initially concentrated into molasses and further carried forward into spent wash and then to effluent collected after its biomethanation treatment. There are three major colorants formed under high temperature, such as melanoidin, caramel and alkaline degradation products. The study on decolorization of biomethated effluent (BME) indicated that the culture of a natural isolate, Aspergillus oryzae JSA-1, decolorized BME effectively by adsorption of color to the cell wall of mycelia. The adsorption yields in the sequential replacement reactions with live mycelial biomass of fungal culture Aspergillus oryzae JSA-1 decreased with the repeated replacement but recovered to almost the initial level after washing the biomass with 0.1 N NaOH solution. The fungal biomass could be effectively used for a minimum of 3 cycles repeatedly to decolorize BME. Besides decolorization, the fungus also removed the COD (chemical oxygen demand) and TDS (total dissolved solids) in BME. It was seen that regeneration of biomass was possible by desorbing the color from the fungal cells which could be an economical solution to treat the huge quantities of effluent. Composting of the exhausted/ saturated biomass with color pigment could be used as rich manure in fields to enrich the soil texture.
Keywordsó Bioremediation, Spent Wash, Decolorization, Biosorption, Desorption, Fungal Cell Wall, Fungal Properties.