The role of stress agents as operating factors in formation and functioning of granular aerobic activated sludge at model domestic wastewater treatment

Abstract

Maintenance of the wastewater treatment plants and increasing the efficiency of existing aerobic biological reactors depend on the stability of activated sludge characteristics under varying wastewater parameters within significant limits and/or influence of some environmental factors. The steady microbial communities observed in biofilms and anaerobic granules of activated sludge can serve as successful samples of formation of the similar aerobic systems. The granular aerobic sludge obtained in the course of our researches is an ideal "plant" on treatment of biogenic pollution at both low and high concentrations. It demonstrates high ability for treatment and stability to adverse factors. To improve aerobic wastewater treatment characteristics, a possibility of using impact of stress conditions upon activated sludge has been studied. Under conditions of fractional hydrogen peroxide addition at diffused lighting, the granular aerobic activated sludge adapted to hydrogen peroxide has been obtained. This sludge has got good sedimentary properties and it differs from the control sample in the species diversity, improved treatment characteristics and also resistance to the stressor. It also endures an impact of one-time hydrogen peroxide addition up to 1.2-1.5 g H2O2/l. The conditions under which the steady aerobic granules of the diameter from 2 to 5 mm were formed with high treatment ability have been chosen. The granules were being stabilized at passages with hydrogen peroxide treatment and they endured up to 2.4-3.0 g/l of one-time H2O2 addition.

Integrative Advanced Oxidation and Biofiltration for Treating Pharmaceuticals in Wastewater

“…A slightly milder decrease was observed in the BAF fed by LPUV/H 2 O 2 effluent (results not shown), likely due to the less mature biomass. Hydrogen peroxide (H 2 O 2 ) is not expected to adversely affect biomass activity or structure at these levels (typically H 2 O 2 is lethal to biomass in the .100 mg/L range: Christensen et al, 1990;Fiorenza and Ward, 1997;Khokhlachev et al, 2014). High transformation of organic matter and NH 3 (with a positive correlation to HRT) indicates an active heterotrophic and autotrophic bacteria community and is consistent with other BAF studies (e.g.…”

Glucose-Oxygen Biofuel Cell with Biotic and Abiotic Catalysts: Experimental Research and Mathematical Modeling

“…In this work, AGS bacterial and fungal communities were employed. AGS was obtained according to the method described in [11]. Based on 16S and 18S rRNA sequence analysis, the individual community cultures were assigned to Fusarium nivale, Fusarium oxysporum, and Penicillium glabrum (fungal communities), Agrobacterium tumefaciens, Bacillus amiloliqefaciens and Microbacterium oxidans (bacterial nitrogen-fixing community).…”

“…The use of fungal and bacterial communities of aerobic granular sludge (AGS) for testing as part of MFC is considered. AGS is selected under specific conditions in the Sequence Batch (SB) mode; starvation and exposure (treatment) by stressors can contribute to the formation of granules [11]. The microorganism communities selected from such granules are extremely resistant to toxicants (for example, heavy metals), mechanical stress, load differences in chemical oxygen demand (COD), carbon substrate, and concentrations of nitrogen and phosphorus.…”

A facile method for formation of synthetic activated sludge granules with enhanced tolerance to metal ion toxicity

“…Some microorganisms were revealed earlier to become dominating, showing a rapid growth and more intensive biomass accumulation in comparison with other organisms of the activated sludge at changes in a number of operating parameters of wastewater treatment facilities (non‐stationary loading or starvation), or under stress. The cultures of such stress‐resistant microorganisms were isolated from the activated sludge samples obtained in a consequent passage regime with fractional hydrogen peroxide addition and starvation, and three cultures with the highest resistance to silver ions were selected as objects of the study and then designated as follows: Fusarium nivale – F.n, Fusarium oxysporum – F.o, and Penicillium glabrum – P.g. These microorganisms showed high tolerance to toxic metal effects which could be explained in some way by their ability to form stable and dense granules.…”