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A comparative study of the internal architecture of anaerobic granular sludges
Author(s) -
Quarmby Joanne,
Forster Christopher F.
Publication year - 1995
Publication title -
journal of chemical technology and biotechnology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.64
H-Index - 117
eISSN - 1097-4660
pISSN - 0268-2575
DOI - 10.1002/jctb.280630109
Subject(s) - wastewater , scanning electron microscope , bacteria , chemistry , blanket , pulp and paper industry , microbiology and biotechnology , food science , materials science , biology , environmental science , composite material , environmental engineering , engineering , genetics
A range of granular sludges was taken from industrial anaerobic sludge blanket reactors treating a wide variety of wastewaters and a comparison was made between their surface and internal structures. Scanning electron microscopy showed a similar surface structure of heterogeneous bacteria, regardless of the type of wastewater being treated. However, a study of the internal structure, using sequential staining of ultra‐thin sections, showed the complexity of granular sludges. The majority of the internally‐located bacteria had a morphology similar to Methanothrix . Much of the area was occupied by Gram‐negative organisms and the area which stained positive for protein was found to increase nearer the centre of the granules. This was accompanied by a decrease in the carbohydrate‐positive areas. Positive areas for lipid were widespread throughout the granules. Changes in the internal structure were observed when the type of wastewater treated by the granules was changed and a comparison between sludges treating the same type of wastewater showed that other factors, such as organic loading rate, pH and chemical oxygen demand may also affect the structure of the granules.