高效降解苯胺好氧颗粒污泥的形成及动力学研究

his study demonstrates that aerobically grown microbial granules fed with aniline as the sole carbon source and energy can be developed to achieve high aniline loading rate in a sequencing airlift bioreactor (SABR). The SABR was started at a loading rate of 0.2 kg•m-3•d-1 with fresh activated sludge as inoculum. The aerobically grown microbial granules first appeared on Day 47 after startup and quickly grew to displace the seed flocs as the dominant form of biomass in the SABR. The aniline loading rate was then adjusted stepwise to a final value of 1.2 kg•m-3•d-1. At this high loading rate, aniline was completely degraded and high biomass concentration was maintained in the SABR. The mature aerobic granules had a mean size of (1.22±0.17)mm, minimal settling velocity of (35.0±1.8) m•h-1, SVI of (45.5±2.5)mL•g-1, SOUR of 91.5 mgDO•gVSS-1•h-1 and specific aniline degradation rate of (0.41±0.42)g•gVSS-1•d-1. The microbial granules consisted of bacterial rods and cocci embedded in an extracellular polymeric matrix (EPS). Degradation kinetics for all tests were well described by the typical substrate inhibition pattern as predicted by the Haldane equation, and the corresponding kinetic coefficients of Vmax, Ks and Ki were (1.40±0.42)g•gVSS-1•d-1, (124.87±34.69)mg•L-1 and (1428.5±53.1)mg•L-1, respectively. The compact structure of aerobic granules offers several advantages, namely easy separation of biomass from bulk liquid during settling phase, protection of cells against the effects of aniline toxicity. Therefore, the aniline-degrading aerobic granules can be exploited to design compact high-rate aerobic granular systems for the treatment of industrial wastewaters containing high concentrations of aniline and other inhibitory chemicals.