Modeling aerobic granules in continuously flowing wastewater-treatment processes.

Continuously flowing wastewater-treatment processes can be configured for biological and physical selection to form and retain large biological aggregates (LBAs), along with suspended biomass that contains ordinary biological flocs and biomass that has detached from the LBAs. Suspended biomass and LBAs have different solids residence times (SRTs) and mass-transport resistances. Here, mathematical sub-models that describe metabolic processes, a 1-D biofilm, and spherical carriers that can migrate throughout a wastewater-treatment process were combined to simulate a full-scale demonstration train having anaerobic, anoxic, and oxic zones, as well as side-stream enhanced biological phosphorus removal.

Mixed-methods multicenter assessment of healthcare workers' knowledge, perceptions, and practices related to blood culture utilization in hospitalized adults.

Objective: To understand healthcare workers' (HCWs) beliefs and practices toward blood culture (BCx) use.

Design: Cross-sectional electronic survey and semi-structured interviews.

Setting: Academic hospitals in the United States.

Hydrazine promoted nitrite reduction in partial-denitrification by enhancing organic-substrate uptake and electron transport.

Partial denitrification coupled with anammox is a promising approach for sustainable nitrogen removal from wastewater. However, this coupling can be influenced by hydrazine (NH) released by anammox bacteria. This study aimed to reveal how NH regulates partial denitrification.

Lead removal by its precipitation with biogenic sulfide in a membrane biofilm reactor.

We evaluated the feasibility of using hydrogen (H)-based membrane biofilm reactors (MBfRs) to promote the growth of hydrogenotrophic sulfate-reducing bacteria (SRB) to remove lead (Pb) through its precipitation as lead sulfide (PbS) via biogenic sulfide (HS) production. Two MBfRs (R1 and R2) were set-up to treat synthetic water rich in sulfate (SO) (585 mg/L) and Pb (50, 100, or 250 mg/L). R1 had one influent that had the Pb and synthetic media mixed together; R2 received the Pb solution and synthetic medium through separate influent lines.

How Rhodococcus ruber accelerated biodegradation of benzophenone-3.

Benzophenone-3 (2-hydroxy-4-methoxybenzophenone, BP-3) poses risks to human health and natural ecosystems, and means to improve its biodegradation are necessary. When a small mass of Rhodococcus ruber, isolated from BP-3-acclimated biomass, was bioaugmented into the acclimated biomass, BP-3 removal was accelerated by 120 %. The first step of BP-3 biodegradation generates either 2,5-dihydroxy-4-methoxybenzophenone (5-OH-BP-3) or benzophenone-1 (2,4-dihydoxybenzophenone, BP-1).

Guidance on aqueous matrices for evaluating novel precipitants and adsorbents for phosphorus removal and recovery.

Phosphorus (P) removal from water and recovery into useable forms is a critical component of creating a sustainable P cycle, although mature technologies for P removal and recovery are still lacking. The goal of this paper was to advance the testing of novel materials for P removal and recovery from water by providing guidance on the development of more realistic aqueous matrices used during materials development. Literature reports of "new" materials to remove P from water are often difficult to compare in terms of performance because authors use a myriad of water chemistries containing P concentrations, pH, and competing ions.

Biotransformation of microplastics from three-layer face masks by nitrifying-denitrifying consortia.

COVID-19 increased microplastics (MP) contamination due to the extensive use of single-use personal protective equipment, particularly three-layer face masks. MP from face masks enter wastewater treatment plants (WWTPs), which were not designed to remove them. We utilized nitrifying-denitrifying microbial consortia and synthetic urban wastewater to evaluate the biotransformation of MP from each layer of three-layer face masks made of polypropylene (PP).

Direct electrosynthesis and separation of ammonia and chlorine from waste streams via a stacked membrane-free electrolyzer.

Electrosynthesis, a viable path to decarbonize the chemical industry, has been harnessed to generate valuable chemicals under ambient conditions. Here, we present a membrane-free flow electrolyzer for paired electrocatalytic upcycling of nitrate (NO) and chloride (Cl) to ammonia (NH) and chlorine (Cl) gases by utilizing waste streams as substitutes for traditional electrolytes. The electrolyzer concurrently couples electrosynthesis and gaseous-product separation, which minimizes the undesired redox reaction between NH and Cl and thus prevents products loss.

The phosphorus challenge: biotechnology approaches for a sustainable phosphorus system.

Phosphorus (P) is essential for growing crops, but the supply of high-quality phosphate rock reserves used for fertilizer production is finite while losses of P from the food/waste system cause considerable environmental damage. A variety of emerging approaches in biotechnology are reviewed that hold promise for improving the sustainability of P use in the food/water systems. These include improved sensors, cell culture approaches to meat production, bio-based P adsorption and transformation strategies, advancements in understanding of polyphosphate-accumulating organisms, and new approaches involving biomineralization and anaerobic treatment.

Microbial ecology of nitrate-, selenate-, selenite-, and sulfate-reducing bacteria in a H2-driven bioprocess.

A hydrogen (H2)-based membrane biofilm reactor (H2-MBfR) can reduce electron acceptors nitrate (NO3-), selenate (SeO42-), selenite (HSeO3-), and sulfate (SO42-), which are in wastewaters from coal mining and combustion. This work presents a model to describe a H2-driven microbial community comprised of hydrogenotrophic and heterotrophic bacteria that respire NO3-, SeO42-, HSeO3-, and SO42-. The model provides mechanistic insights into the interactions between autotrophic and heterotrophic bacteria in a microbial community that is founded on H2-based autotrophy.

Microalgal extracellular polymeric substances (EPS) and their roles in cultivation, biomass harvesting, and bioproducts extraction.

Microalgae extracellular polymeric substances (EPS) are complex high-molecular-weight polymers and the physicochemical properties of EPS strongly affect the core features of microalgae cultivation and resource utilization. Revealing the key roles of EPS in microalgae life-cycle processes in an interesting and novelty topic to achieve energy-efficient practical application of microalgae. This review found that EPS showed positive effect in non-gas uptake, extracellular electron transfer, toxicity resistance and heterotrophic symbiosis, but negative impact in gas transfer and light utilization during microalgae cultivation.

Achieving Long-Term Stability of Partial Nitrification and Autotrophic Denitrification in an MABR Sulfide Dosing.

While partial nitrification (PN) has the potential to reduce energy for aeration, it has proven to be unstable when treating low-strength wastewater. This study introduces an innovative combined strategy incorporating a low rate of oxygen supply, pH control, and sulfide addition to selectively inhibit nitrite-oxidizing bacteria (NOB). This strategy led to a stable PN in a laboratory-scale membrane aerated biofilm reactor (MABR).

Optimized bimetallic ratios for durable membrane catalyst-film reactors in treating nitrate-polluted water.

Nitrate contamination of surface and ground water is a significant global challenge. Most current treatment technologies separate nitrate from water, resulting in concentrated wastestreams that need to be managed. Membrane Catalyst-film Reactors (MCfR), which utilize in-situ produced nanocatalysts attached to hydrogen-gas-permeable hollow-fiber membranes, offer a promising alternative for denitrification without generating a concentrated wastestream.

Cooperation and competition between denitrification and chromate reduction in a hydrogen-based membrane biofilm reactor.

Competition and cooperation between denitrification and Cr(VI) reduction in a H-based membrane biofilm reactor (HMBfR) were documented over 55 days of continuous operation. When nitrate (5 mg N/L) and chromate (0.5 mg Cr/L) were fed together, the HMBfR maintained approximately 100 % nitrate removal and 60 % chromate Cr(VI) removal, which means that nitrate outcompeted Cr(VI) for electrons from H oxidation.

Biogenic Palladium Improved Perchlorate Reduction during Nitrate Co-Reduction by Diverting Electron Flow in a Hydrogenotrophic Biofilm.

Microbial reduction of perchlorate (ClO) is emerging as a cost-effective strategy for groundwater remediation. However, the effectiveness of perchlorate reduction can be suppressed by the common co-contamination of nitrate (NO). We propose a means to overcome the limitation of ClO reduction: depositing palladium nanoparticles (PdNPs) within the matrix of a hydrogenotrophic biofilm.

Co-Removal of Perfluorooctanoic Acid and Nitrate from Water by Coupling Pd Catalysis with Enzymatic Biotransformation.

PFAS (poly- and per-fluorinated alkyl substances) represent a large family of recalcitrant organic compounds that are widely used and pose serious threats to human and ecosystem health. Here, palladium (Pd)-catalyzed defluorination and microbiological mineralization were combined in a denitrifying H-based membrane biofilm reactor to remove co-occurring perfluorooctanoic acid (PFOA) and nitrate. The combined process, i.

Heterotrophic bacteria isolated from a chloraminated system accelerate chloramine decay.

This work comprehensively demonstrates the ability of heterotrophic bacteria, isolated from a chloraminated system, to decay chloramine. This study non-selectively isolated 62 cultures of heterotrophic bacteria from a water sample (0.002 mg-N/L nitrite and 1.

An integrated evaluation of bioenhanced in situ LNAPL dissolution.

Performance evaluation of in situ bioremediation processes in the field is difficult due to uncertainty created by matrix and contaminant heterogeneity, inaccessibility to direct observation, expense of sampling, and limitations of some measurements. The goal of this research was to develop a strategy for evaluating in situ bioremediation of light nonaqueous-phase liquid (LNAPL) contamination and demonstrating the occurrence of bioenhanced LNAPL dissolution by: (1) integrating a suite of analyses into a rational evaluation strategy; and (2) demonstrating the strategy's application in intermediate-scale flow-cell (ISFC) experiments simulating an aquifer contaminated with a pool of LNAPL (naphthalene dissolved in dodecane). Two ISFCs were operated to evaluate how the monitored parameters changed between a "no bioremediation" scenario and an "intrinsic in situ bioremediation" scenario.

Differentiation and quantification of extracellular polymeric substances from microalgae and bacteria in the mixed culture.

Extracellular polymeric substances (EPS) play significant roles in the formation, function, and interactions of microalgal-bacteria consortia. Understanding the key roles of EPS depends on reliable extraction and quantification methods, but differentiating of EPS from microalgae versus bacteria is challenging. In this work, cation exchange resin (CER) and thermal treatments were applied for total EPS extraction from microalgal-bacteria mixed culture (MBMC), flow cytometry combined with SYTOX Green staining was applied to evaluate cell disruption during EPS extraction, and auto-fluorescence-based cell sorting (AFCS) was used to separate microalgae and bacteria in the MBMC.

Elemental sulfur biorecovery from phosphogypsum using oxygen-membrane biofilm reactor: Bioreactor parameters optimization, metagenomic analysis and metabolic prediction of the biofilm activity.

This work investigated elemental sulfur (S) biorecovery from Phosphogypsum (PG) using sulfur-oxidizing bacteria in an O-based membrane biofilm reactor (MBfR). The system was first optimized using synthetic sulfide medium (SSM) as influent, then switched to biogenic sulfide medium (BSM) generated by biological reduction of PG alkaline leachate. The results using SSM had high sulfide-oxidation efficiency (98 %), sulfide to S conversion (∼90 %), and S production rate up to 2.

Deconjugation potentials of natural estrogen conjugates in sewage and wastewater treatment plant: New insights from model prediction and on-site investigations.

Natural estrogen conjugates play important roles in municipal wastewater treatment plant (WWTP), but their deconjugation potentials are poorly understood. This work is the first to investigate the relationships between the enzyme activities of arylsulfatase/β-glucuronidase and deconjugation potentials of natural estrogen conjugates. This work led to three important findings.

Method of H Transfer Is Vital for Catalytic Hydrodefluorination of Perfluorooctanoic Acid (PFOA).

The efficient transfer of H plays a critical role in catalytic hydrogenation, particularly for the removal of recalcitrant contaminants from water. One of the most persistent contaminants, perfluorooctanoic acid (PFOA), was used to investigate how the method of H transfer affected the catalytic hydrodefluorination ability of elemental palladium nanoparticles (PdNPs). PdNPs were synthesized through an in situ autocatalytic reduction of Pd driven by H from the membrane.