INFLUENCE OF INTERMITTEN AERATION IN AEROBIC GRANULAR FORMATION USING AIRLIFT REACTOR WITH CONTINOUS FLOW SYSTEM

• Main Author: TIARA BENING NIM : 25315307, ASTRID
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/25886
• Institution: Institut Teknologi Bandung

A denser granulation with a smaller diameter was obtained from the Airlift reactor at the substrate loading level equal to the bubble column reactor. The granulation formation utilizes upflow sludge bed reactor pattern and oxygen contactor without partial waste recirculation by placing aeration zone in the riser and downcomer parts of the Airlift reactor system. The availability control of oxygen had an important effect on the viability of microorganisms, granular microstructure. Therefore, the development of reasearch on biogranular formation as carried out by providing intermitten aeration variation (3 liters/minute; 2,55 cm/s) in periods of 2, 3, and 4 hours (HRT 6 hours; OLR 2.5 kg COD/m3.day; CH3COONa as a carbon source) in an Airlift reactor with continuous flow system (H/D 12.5 outside and 20 internal parts). The condition of aerobic formation was better after giving intermitten aeration variation in the 4 hour period by using pairwise comparison method. This was because there were 3 aeration patterns per day and 3 patterns without aeration per day, the pattern was relatively fewer than the other two variations, so the biomass was relatively more stable and compact. The biogranular characteristics were 85 - 88 mL/g; 32.95 cm/min; 13.28 g/L; 1.87 mm and 0.67 of SVI value, setlling veolicty, density, diameter and aspect ratio respectively. Removal efficiency of organic, ammonium and nitrate obtained from the variation were the highest among another two variations, which were 58.35%; 26.56%; 25.75% for organic, ammonium and nitrate respectively.The kinetic models used to evaluate the performance of microorganisms were Monod and Contois model, with parameters Y, Kd, μmaks Monod, Ks, μmax Contois and β. Both kinetic models were less precise in evaluating substrate used by biomass so that the use of second-order Grau and Stover-Kincannon kinetics models was tested. Of the two kinetic models, the second-order Grau kinetics model was more suitable for tracing substrate used by biomass in the intermitten aeration variation, with relatively small error compared to the other three models (ε = ± 0.001 - 0.004 g / L), the confidence index of 65.10%.