Effect of continuous addition of an organic substrate to the anoxic phase on biological phosphorus removal

Jens Meinhold, Heinz Pedersen, Eva Arnold, Steven Howard Isaacs, Mogens Henze

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The continuous introduction of a biological phosphorus removal (BPR) promoting organic substrate to the denitrifying reactor of a BPR process is examined through a series of batch experiments using acetate as model organic substrate. Several observations are made regarding the influence of substrate availability on PHA storage/utilization and phosphate uptake/release. Under anoxic conditions PHB is utilized and phosphate is taken up, indicating that at least a fraction of the PAO can denitrify. The rates of anoxic P-uptake, PHB utilization and denitrification are found to increase with increasing initial PHB level. At low acetate addition rates the P-uptake and PHB utilization rates are reduced compared to when no acetate is available. At higher acetate addition rates a net P-release occurs and PHB is accumulated. For certain intermediate acetate addition rates the PHB level can increase while a net P-release occurs. Whether the introduction of BPR promoting organic substrates to the denitrifying reactor is detrimental to overall P-removal appears to be dependent on the interaction between aerobic P-uptake, which is a function of PHB level, and the aerobic residence time. (C) 1998 Published by Elsevier Science Ltd. All rights reserved.
Original languageEnglish
JournalWater Science and Technology
Issue number1
Pages (from-to)97-105
Publication statusPublished - 1998
Event19th Biennial Conference of the International-Association-on-Water-Quality - Vancouver, Canada
Duration: 21 Jun 199826 Jun 1998
Conference number: 19


Conference19th Biennial Conference of the International-Association-on-Water-Quality


  • activated sludge
  • anoxic phosphate uptake
  • biological phosphorus removal
  • denitrification
  • PHB
  • nutrient removal
  • organic substrate addition
  • waste water treatment

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