Studies on fluoride removal using adsorption process.

Batch adsorption studies were undertaken to assess the suitability of commercially available activated charcoal to remediate fluoride-contaminated water. The effects of some of the major parameters of adsorption, viz. pH, dose of adsorbent, rate of stirring, contact time and initial adsorbate concentration on fluoride removal efficiency were studied and optimized. The optimum sorbent dose was found to be 2.0 g/100 mL, equilibrium was achieved in 120 minutes and enhanced adsorption was obtained at pH 2. Maximum fluoride removal was observed to be 94% at optimum conditions. Freudlich as well as Langmuir isotherms were plotted and kinetic constants were determined.

Study of hydrodynamic behavior of a laboratory scale upflow anaerobic fixed film fixed bed reactor.

Application of anaerobic fixed film fixed bed reactor (AFFFB), containing mixed population of bacteria, helps in bacterial immobilization as biofilm on a support medium in the reactor overcoming the problem of biomass washout. Knowledge of hydrodynamics characteristics helps in better understanding and evaluating the performance of any reactor. This paper presents residence time distribution (RTD) studies carried out to investigate the hydrodynamic behavior of AFFFB reactor under the influence of varied hydraulic loading resulting in HRTs in range 24 hrs to 6 hrs. Results have demonstrated that the flow pattern is more close to a plug flow type and vary with varying intensity of dispersion and the extent of dispersion increases with decrease in HRTs.