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).