In order to examine the optimal design and operating parameters, kinetics for microbiological reaction and oxygen consumption in composting of waste activated sludge were quantitatively examined. A series of experiments was conducted to discuss the optimal operating parameters for aerobic composting of waste activated sludge obtained from Kawagoe City Wastewater Treatment Plant (Saitama, Japan)...

The Microbial Database for Activated Sludge (MiDAS) field guide is a freely available online resource linking the identity of abundant and process critical microorganisms in activated sludge wastewater treatment systems to available data related to their functional importance. Phenotypic properties of some of these genera are described, but most are known only from sequence data. The MiDAS taxo...

The diversity of different bacterial groups of activated sludge samples that received wastewater from four different types of industry was investigated by a nested PCR-DGGE (denaturing gradient gel electrophoresis) approach. Specific 16S rRNA primers were chosen for large bacterial groups (Bacteria and α-Proteobacteria in particular), which dominate activated sludge communities, as well as for ...

Wastewater treatment based on activated sludge is known to be one of the most effective and popular wastewater purification methods. An estimation of microbial community variability in activated sludge allows us to observe the correlation between a particular bacterial group's appearance and the effectiveness of the removal of chemical substances. This research is focused on microbial community...

The viral metagenome within an activated sludge microbial assemblage was sampled using culture-dependent and culture-independent methods and compared to the diversity of activated sludge bacterial taxa. A total of 70 unique cultured bacterial isolates, 24 cultured bacteriophages, 829 bacterial metagenomic clones of 16S rRNA genes, and 1,161 viral metagenomic clones were subjected to a phylogene...

The kinetics of sulfate reduction and cell densities of sulfate-reducing bacteria (SRB) were determined in activated sludge at Aalborg East wastewater treatment plant, a modern 100 000 person equivalent plant, where SRB are subjected to alternating cycles of oxic and anoxic conditions. The number of SRB was relatively constant over the year, ranging from 2.1x10(5) to 1.1x10(6) cells ml(-1) as d...

A novel computational fluid dynamics-population balance model (CFD-PBM) for the simulation of gas mixing in activated sludge (i.e., an opaque non-Newtonian liquid) in a bubble column is developed and described to solve the problem of measuring the hydrodynamic behavior of opaque non-Newtonian liquid-gas two-phase flow. We study the effects of the inlet position and liquid-phase properties (wate...

The Combined Activated Sludge-Anaerobic Digestion Model (CASADM) quantifies the effects of recycling anaerobic-digester (AD) sludge on the performance of a hybrid activated sludge (AS)-AD system. The model includes nitrification, denitrification, hydrolysis, fermentation, methanogenesis, and production/utilization of soluble microbial products and extracellular polymeric substances (EPS). A CAS...

Activated sludge systems are biological processes greatly used in wastewater treatment plants (WWTPs). These systems are composed of an aerated tank where the biochemical phase occurs and a settler where the physical phase takes place. Solid-liquid separation is one of the most critical steps in activated sludge processes. This stage presents three main objectives: sludge thickening, effluent c...