Solid-liquid redistribution and degradation of antibiotics during hydrothermal treatment of sewage sludge: Interaction between biopolymers and antibiotics.

Waste activated sludge serves an important reservoir for antibiotics within wastewater treatment plants, and understanding the occurrence and evolution of antibiotics during sludge treatment is crucial to mitigate the potential risks of subsequent resource utilization of sludge. This study explores the degradation and transformation mechanisms of three typical antibiotics, oxytetracycline (OTC), ofloxacin (OFL), and azithromycin (AZI) during sludge hydrothermal treatment (HT), and investigates the influence of biopolymers transformation on the fate of these antibiotics. The findings indicate that HT induces a shift of antibiotics from solid-phase adsorption to liquid-phase dissolution in the initial temperature range of 25-90 °C, underscoring this phase's critical role in preparing antibiotics for subsequent degradation phases. Proteins (PN) and humic acids emerge as crucial for antibiotic binding, facilitating their redistribution within sludge. Specifically, the binding capacity sequence of biopolymers to antibiotics is as follows: OFL>OTC>AZI, highlighting that OFL-biopolymers display stronger electrostatic attraction, more available adsorption sites, and more stable binding strength. Furthermore, antibiotic degradation mainly occurs above 90 °C, with AZI being the most temperature-sensitive, degrading 92.97% at 180 °C, followed by OTC (91.26%) and OFL (52.51%). Concurrently, the degradation products of biopolymers compete for active sites to form novel amino acid-antibiotic conjugates, which inhibits the further degradation of antibiotics. These findings illuminate the effects of biopolymers evolution on intricate dynamics of antibiotics fate in sludge HT and are helpful to optimize the sludge HT process for effective antibiotics abatement.

Ginseng polysaccharides ameliorate ulcerative colitis via regulating gut microbiota and tryptophan metabolism.

Ulcerative colitis (UC) is regarded as a recurring inflammatory disorder of the gastrointestinal tract, for which treatment approaches remain notably limited. In this study, we demonstrated that ginseng polysaccharides (GPs) could alleviate the development of dextran sulfate sodium (DSS)-induced UC as reflected by the ameliorated pathological lesions in the colon. GPs strikingly suppressed the expression levels of multiple inflammatory cytokines, as well as significantly inhibited the infiltration of inflammatory cells. Microbiota-dependent investigations by virtue of 16S rRNA gene sequencing, antibiotic treatment and fecal microbiota transplantation illustrated that GPs treatment prominently restored intestinal microbial balance predominantly through modulating the relative abundance of Lactobacillus. Additionally, GPs remarkably influenced the levels of microbial tryptophan metabolites, diminished the intestinal permeability and strengthened intestinal barrier integrity via inhibiting the 5-HT/HTR3A signaling pathway. Taken together, the promising therapeutic potential of GPs on the development of UC predominantly hinges on the capacity to suppress the expression of inflammatory cytokines as well as to influence Lactobacillus and microbial tryptophan metabolites.

Novel multiplexed alkali enzyme lysis coupled with EDTA pretreatment for RNA virus extraction from wastewater sludge: Optimization, recovery, and detection.

RNA viruses are readily enriched in wastewater sludge owing to adsorption by extracellular polymeric substances (EPS) during wastewater treatment, causing pathogenicity. However, conventional wastewater extraction methods often fail to fully extract these viruses from sludge. In this study, three methods: enzymatic (ENP), alkaline (ALP), and ethylenediaminetetraacetic acid (EDTA) pretreatments were applied to sludges and promote the RNA virus extraction from sludge. Our results show that the total recovery rate of RNA viruses increased by 87.73% after ENP pretreatment, whereas ALP pretreatment inhibited virus extraction. The highest recovery rate of viruses from sludge, reaching 296.80%, was achieved with EDTA pretreatment (EDP) coupled with ENP. Notably, the most significant increase was observed in the abundance of Astroviruses, which increased from 7.60 × 107 to 7.86 × 108 copies/g TSS after EDP + ENP treatment. Our investigations revealed that virus extraction was affected by a class of short-wavelength protein substances, as opposed to tryptophan or tyrosine, which were eluted by proteins with beef paste buffer by substitution after EDP + ENP treatment. The results of this study provide essential insights for sludge-based epidemiology with the required sensitivity for managing the extraction of RNA epidemic viruses to control viral transmission.