High-rate activated sludge communities have a distinctly different structure compared to low-rate sludge communities, and are less sensitive towards environmental and operational variables

Water Res. 2016 Sep 1:100:137-145. doi: 10.1016/j.watres.2016.04.076. Epub 2016 May 7.

Abstract

High-rate activated sludge processes allow for the recovery of organics and energy from wastewaters. These systems are operated at a short sludge retention time and high sludge-specific loading rates, which results in a higher sludge yield and better digestibility than conventional, low-rate activated sludge. Little is known about the microbial ecology of high-rate systems. In this work, we address the need for a fundamental understanding of how high-rate microbial communities differ from low-rate communities. We investigated the high-rate and low-rate communities in a sewage treatment plant in relation to environmental and operational variables over a period of ten months. We demonstrated that (1) high-rate and low-rate communities are distinctly different in terms of richness, evenness and composition, (2) high-rate community dynamics are more variable and less shaped by deterministic factors compared to low-rate communities, (3) sub-communities of continuously core and transitional members are more shaped by deterministic factors than the continuously rare members, both in high-rate and low-rate communities, and (4) high-rate community members showed a co-occurrence pattern similar to that of low-rate community members, but were less likely to be correlated to environmental and operational variables. These findings provide a basis for further optimization of high-rate systems, in order to facilitate resource recovery from wastewater.

Keywords: A-stage; AB-system; Co-occurrence network analysis; Energy-neutral sewage treatment; Resource recovery.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Environment
  • Sewage / chemistry*
  • Wastewater*

Substances

  • Sewage
  • Waste Water