Strength characterisation of microbial granules

Abstract

Research Article| September 01 1997 Strength characterisation of microbial granules J. H. F. Pereboom J. H. F. Pereboom Search for other works by this author on: This Site PubMed Google Scholar Water Sci Technol (1997) 36 (6-7): 141–148. https://doi.org/10.2166/wst.1997.0585 Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Cite Icon Cite Permissions Search Site Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentAll JournalsThis Journal Search Advanced Search Citation J. H. F. Pereboom; Strength characterisation of microbial granules. Water Sci Technol 1 September 1997; 36 (6-7): 141–148. doi: https://doi.org/10.2166/wst.1997.0585 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex The strength of microbial granules is still poorly understood. The granule strength is defined as the resistance to attrition and/or breaking by a mechanical force or the liquid shear stress. The strength of various types of microbial granules were studied. The objective was to develop an in vitro strength characterisation test and to be able to predict granule behaviour in full scale systems. Abrasion experiments were conducted in stirred tanks and bubble columns, while the influence of viscosity and medium composition, shear rate and particle size were studied.The medium viscosity did not influence the relation between shear rate and abrasion. Measurements in demineralized water or media containing complexing agents resulted in lower granule strengths presumably the result of the removal of calcium from the granule matrix. In bubble columns attrition is the predominant abrasion process. In full scale reactors, e.g. UASB, attrition is apparently insignificant. In stirred tanks also granule breakage was observed. The abrasion rate is not directly related to the stirrer tip speed. Larger methanogenic granules showed more abrasion compared to small ones. In contrast larger nitrifying granules were stronger than small ones.A standardized strength characterization test was developed to be able to compare strengths of different microbial granules. The strength of slow growing systems appeared to be higher as compared to fast growing systems. From an ecological point of view, cells growing slowly in continuous operated systems gain advantage from attachment and shear resistance or strength. abrasion, biofilm, microbial granules, granule strength, nitrification, UASB-reactor This content is only available as a PDF. © IWA Publishing 1997 You do not currently have access to this content.