A COMPARISON BETWEEN BIOSORPTION AND BIOACCUMULATION OF FLUORIDE FROM WASTE WATER.

摘要

Objective: The comparison between the properties of two removal methods viz. adsorptive removal (biosorption) and simultaneous adsorption and bioaccumulation (SAB) of fluoride from waste water was investigated. Methods: In the present study, bioaccumulation study was done on Sweet Lemon peel. Acinetobacter baumannii (Mtcc no-11451) is a water living microorganism which survives in waste water. Microorganism (Acinetobacter baumannii (Mtcc no-11451)) immobilized on the surface of Sweet Lemon peel. The size of microorganism is greater than the pore size of adsorbent. Active sites of the adsorbent are blocked due to immobilization of microorganism on the surface of adsorbent. Different optimizing parameters are studied during the experiments like adsorbent dose, pH, initial concentration and contact time for bio bioaccumulation process. Results: It was observed that adsorption and bioaccumulation process execute simultaneously but mainly bioaccumulation is responsible for removal of fluoride. The removal efficiency of fluoride sees a drastic increase from 59.59 % to 99.49 % in optimum conditions. It is to be noted that simple adsorption process removal efficiency was 95.795 % at optimum time (60 min), pH 4.0 and dose 10 g/l. Adsorption isotherm parameters are well fitted for Freundlich whereas simple adsorption follow Langmuir isotherm model. Conclusion: The removal of fluoride occurred due to the accumulation by bacteria. Kinetic result revealed that bioaccumulation is a slower process. Bioaccumulation process increase the removal efficiency but it is very time consuming and costly as compare to the simple adsorption process.