Start-up procedures and analyses of sludge characteristics in a novel double circle anaerobic reactor for treating traditional Chinese medicine wastewater.

The start-up procedures and characteristics of the granular sludge from a novel double circle (DC) anaerobic reactor for treating traditional Chinese medicine (TCM) wastewater were investigated. Following a start-up period, the DC reactor demonstrated good chemical oxygen demand removal at 96.87%. The Fourier transform infrared spectra and excitation-emission matrix (EEM) fluorescence spectra from the soluble microbial products of the effluent showed that amino acid and aromatic compounds in TCM wastewater were effectively removed by the DC reactor. The peak of the particle size distribution from the granular sludge in the first reaction area of the DC reactor ranged from 700 to 1500 µm with a mean size of 513 µm, and the mean size of the granular sludge in the second reaction area was approximately 250 µm. The protein-like peak in the EEM fluorescence clearly decreased and the coenzyme F420 of the fluorescence peak clearly increased for the extracellular polymeric substances of the granular sludge.