Effects of aeration strategy on the evolution of dissolved organic matter (DOM) and microbial community structure during sludge bio-drying

Abstract

Sludge bio-drying in which sludge is dried by means of the heat generated by the aerobic degradation of its own organic substances has been widely used for sludge treatment. A better understanding of the evolution of dissolved organic matter (DOM) and its degradation drivers during sludge bio-drying could facilitate its control. Aeration is one of the key factors that affect sludge bio-drying performance. In this study, two aeration strategies (pile I-the optimized and pile II-the current) were established to investigate their impacts on the evolution of DOM and the microbial community in a full-scale sludge bio-drying plant. A higher pile temperature in pile I caused pile I to enter the DOM and microbiology stable stage approximately2 days earlier than pile II. The degradation of easily degradable components in the DOM primarily occurred in the thermophilic phase; after that degradation, the DOM components changed a little. Along with the evolution of the DOM, its main degradation driver, the microbial community, changed considerably. Phyla Firmicutes and Proteobacteria were dominant in the thermophilic stage, and genus Ureibacillus, which was the primary thermophilic bacteria, was closely associated with the degradation of the DOM. In the mesophilic stage, the microbial community changed significantly at first and subsequently stabilized, and the genus Parapedobacter, which belongs to Bacteriodetes, became dominant. This study elucidates the interplay between the DOM and microbial community during sludge bio-drying.

Bacterial communities in the small intestine respond differently to those in the caecum and colon in mice fed low- and high-fat diets

“…Gram-negative bacteria uniquely detected in the small intestine included five genera belonging to the Bacteroidetes. The five genera identified, Olivibacter, Parapedobacter, Polaribacter, Sphingobacterium and Thiothrix spp., have been identified in various environmental samples such as water and soil samples [26][27][28][29][30]. Since aerobic growth is reported for several of these genera, e.g.…”

Impacts of addition of natural zeolite or a nitrification inhibitor on antibiotic resistance genes during sludge composting

“…The effects of various sludge digestion conditions on the removal of ARGs, including thermal hydrolysis pretreatment, thermophilic and mesophilic anaerobic digestion conditions, have been investigated in detail (Ma et al, 2011;Zhang et al, 2015c). While natural zeolite is usually added for nitrogen conservation, to reduce NH 3 emissions and to reduce atmospheric pollution, and a nitrification inhibitor addition has also be demonstrated to be a promising way for nitrogen conservation during sludge composting (Zhang et al, 2015a). The addition of natural zeolite and a nitrification inhibitor during sludge composting might offer an added benefit for the removal of ARGs, although this has not been experimentally determined.…”

Multiple effects of trace elements on methanogenesis in a two-phase anaerobic membrane bioreactor treating starch wastewater

“…The microbial mechanism of TEs' multiple effects on methanogenesis of the two-phase AnMBR was studied by analysing microbial community structure (Vanwonterghem et al 2014;Zhang et al 2015). Microbial community structure was analysed in the recovery groups because their differentiation induced by TEs was more significant after twice AD.…”

“…The taxonomic classification of the sequences of each sample was carried out individually using the RDP Classifier, and the sequences to different taxonomy levels were assigned at the bootstrap cut-off of 50 % suggested by the RDP (Wang et al 2007). In addition, the diversity and richness indices were calculated using the relevant RDP pipeline modules as previously (Zhang et al 2015). Correlations between microbial community structures and their functions were analysed by redundancy analysis (RCA) method using CANOCO 5.0.…”