Skip to main content

Evaluation of substrate and pH effects in a nitrifying biofilm

Buy Article:

$22.00 plus tax (Refund Policy)

The effects of substrate and pH on biofilm nitrification were studied using a microelectrode technique and a microslicing technique. Three different kinds of biofilms were cultured using lab-scale, rotating drum biofilm reactors fed with synthetic wastewaters. The measured concentration profiles provide direct experimental evidence of the substrate and pH effects on biofilm nitrification. It was found that pH decreases within the nitrifying biofilm depended on the mole ratio of HCO 3/O2. When this mole ratio was >5, the maximum pH decrease within the nitrifying biofilm was <0.4–0.6 pH units. When this ratio was <3, the maximum pH decrease could be 1.4–1.6 pH units. A pH decrease of 1.4–1.6 pH units resulted in an inhibition of the biofilm nitrification process, and therefore stopped a further decrease in pH. No dramatic pH decrease (>2–2.5) was observed during the study. It was found that increases in glucose loading or ammonium loading caused more consumption of oxygen, which resulted in inhibition of the biofilm nitrification. The bacterial trophic population measurement revealed that even in a pure nitrification system, heterotrophs could exist in the nitrifying biofilm. In biofilms cultured with an influent COD of 170 mg/L or higher, the numbers of nitrifiers were always four to five orders lower than those of heterotrophs. This study demonstrates that competition between heterotrophs and nitrifiers for substrate (including O2) and space greatly affects the degree of pH decreases within nitrifying biofilms.
No Reference information available - sign in for access.
No Citation information available - sign in for access.
No Supplementary Data.
No Article Media
No Metrics


Document Type: Research Article

Publication date: 1996-11-01

More about this publication?
  • Water Environment Research (WER) is published monthly, including an annual Literature Review. A subscription to WER includes access to the latest content back to 1992, as well as access to fast track articles. An individual subscription is valid for 12 months from month of purchase.

    Water Environment Research (WER) publishes peer-reviewed research papers, research notes, state-of-the-art and critical reviews on original, fundamental and applied research in all scientific and technical areas related to water quality, pollution control, and management. An annual Literature Review provides a review of published books and articles on water quality topics from the previous year.

    Published as: Sewage Works Journal, 1928 - 1949; Sewage and Industrial Wastes, 1950 - 1959; Journal Water Pollution Control Federation, 1959 - Oct 1989; Research Journal Water Pollution Control Federation, Nov 1989 - 1991; Water Environment Research, 1992 - present.
  • Editorial Board
  • Information for Authors
  • Submit a Paper
  • Subscribe to this Title
  • Membership Information
  • Information for Advertisers
  • WEF Bookstore
  • Ingenta Connect is not responsible for the content or availability of external websites
  • Access Key
  • Free content
  • Partial Free content
  • New content
  • Open access content
  • Partial Open access content
  • Subscribed content
  • Partial Subscribed content
  • Free trial content
Cookie Policy
Cookie Policy
Ingenta Connect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more