STUDIES ON REMOVAL OF PHENOLIC COMPOUNDS IN BIOFILTER TOWER

Abstract

Phenol and phenolic compounds are the most important constituents 01 the diluent that comes from various industries like pulp and paper, oil refineries, coke oven plants, steel plants, pesticides, insecticides, plastics, textile, dyes, polymeric resin and pharmaceutical industries etc. This water requires careful treatment hcftrc being discharged into the receiving stream of water. Treatment of this waste water is challenging problem for a engineer. In present study phenol biodegradation has been carried out by using Pseudomonas putida 1194 (cultures acquired from IMTECH Chandigarh) in Biofilter tower packed with granular activated carbon (GAC). Batch study has been performed to find out the reaction kinetics of phenol biodegradation in free cell (suspension culture) system, optimum pH and particle size of GAC in presence of pseudomonas putida. Haldanes model fitted with experimental data, and value of the copnstant was found. Optimum pH and particle size were found to be 6.75 and 2-4mm respectively. In the bio-filter tower bed material was taken as GAC hence this tower also called biological activated carbon tower. Since GAC is a good adsorbent so adsorption study also performed. A comparative study has been performed between adsorption and simultaneous adsorption & biodegradation (SAB) for the tower. Filtration tower experiment was carried out at various input flow rates for fresh activated carbon as well biologically activated carbon. It was found that the reactor performance was increased by using microorganism, hence removal rate of phenol enhanced as compared to the one fresh activated carbon. Break through point was calculated for the fresh activated carbon and biologically activated carbon and it was found more for the biologically activated carbon. With the increasing flow rate outlet concentration of phenol from tower decreased, but phenol biodegradation rate first increased with increase in flow rate and reached a maximum value then start to fall. Maximum phenol degradation rate was found to be 120 mg/l/h at flow rate 7.42 ml/min. After reaching the exhaustion stage, GAC was bio regenerated in 20 hrs duration. Later break through curves have been found out and reactor performance and percentage regeneration has been determined experimentally.