Enhancing rejection of short-chain per- and polyfluoroalkyl substances by tailoring the surface charge of nanofiltration membranes.

Nanofiltration (NF) effectively removes per- and polyfluoroalkyl substances (PFAS) from water but struggles with short-chain PFAS (i.e., those containing less than 6 perfluorinated carbons) due to size exclusion inefficiency.

Enhancing nitrogen and phosphorus removal in plant-biochar-pyrite stormwater bioretention systems: Impact of temperature and high-frequency heavy rainfall.

Global climate change and rapid urbanization have resulted in more frequent and intense rainfall events in urban areas, raising concerns about the effectiveness of stormwater bioretention systems. In this study, we optimized the design by constructing a multi-layer filler structure, including plant layer, biochar layer, and pyrite layer, and evaluated its performance in nitrogen (N) and phosphorus (P) removal under different temperatures (5-18 °C and 24-43 °C), rainfall intensity (47.06 mm rainfall depth), and frequency (1-5 days rainfall intervals) conditions.

A self-sustaining effect induced by iron sulfide generation and reuse in pyrite-woodchip mixotrophic bioretention systems: An experimental and modeling study.

Dual electron donor bioretention systems have emerged as a popular strategy to enhance dissolved nitrogen removal from stormwater runoff. Pyrite-woodchip mixotrophic bioretention systems showed a promoted and stabilized removal of dissolved nutrients under complex rainfall conditions, but the sulfate reduction process that can induce iron sulfide generation and reuse was overlooked. In this study, experiments and models were applied to investigate the effects of filler configuration and dissolved organic carbon (DOC) dissolution rate on treatment performance and iron sulfide generation in pyrite-woodchip bioretention systems.

Removal, accumulation, and micro-ecosystem impacts of typical POPs in bioretention systems with different media: A runoff infiltration study.

Bioretention systems prove effective in purifying common persistent organic pollutants (POPs) found in urban rainfall runoff. However, the response process of the microecosystem in the media becomes unclear when POPs accumulate in bioretention systems. In this study, we constructed bioretention systems and conducted simulated rainfall tests to elucidate the evolution of micro-ecosystems within the media under typical POPs pollution.

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.

Promoting oxygen vacancies utility for tetracycline degradation via peroxymonosulfate activation by reduced Mg-doped CoO: Kinetics and key role of electron transfer pathway.

Developing cobalt-based catalysts with a high abundance of oxygen vacancies (V) and exceptional V utility efficiency for the prompt removal of stubborn contaminants through peroxymonosulfate (PMS) activation poses a significant challenge. Herein, we reported the synthesis of the reduced Mg-doped CoO nanosheets, i.e.

Multi-media interaction improves the efficiency and stability of the bioretention system for stormwater runoff treatment.

Bioretention systems are one of the most widely used stormwater control measures for urban runoff treatment. However, stable and effective dissolved nutrient treatment by bioretention systems is often challenged by complicated stormwater conditions. In this study, pyrite-only (PO), pyrite-biochar (PB), pyrite-woodchip (PW), and pyrite-woodchip-biochar mixed (M) bioretention systems were established to study the feasibility of improving both stability and efficiency in bioretention system via multi-media interaction.

Smaller Aerobic Granules Significantly Reduce NO Production by Ammonia-Oxidizing Bacteria: Evidences from Biochemical and Isotopic Analyses.

The mitigation of nitrous oxide (NO) is of primary significance to offset carbon footprints in aerobic granular sludge (AGS) systems. However, a significant knowledge gap still exists regarding the NO production mechanism and its pathway contribution. To address this issue, the impact of varying granule sizes, dissolved oxygen (DO), and nitrite (NO) levels on NO production by ammonia-oxidizing bacteria (AOB) during nitrification in AGS systems was comprehensively investigated.

Nitrite improved nitrification efficiency and enriched ammonia-oxidizing archaea and bacteria in the simultaneous nitrification and denitrification process.

Simultaneous nitrification and denitrification (SND) is effective and energy-saving for wastewater treatment. As an inevitable intermediate product in the SND process, nitrite affects the efficiency of ammonia oxidation and the composition of nitrifiers. To investigate the impact of nitrite on ammonia oxidation efficiency, two reactors performing SND were respectively operated without nitrite (R1 as control) and with 20 mg N/L nitrite addition (R2 as experimental).

Insights into the transport and bio-degradation of dissolved inorganic nitrogen in the biochar-pyrite amended stormwater biofilter using dynamic modeling.

The stormwater biofilter is a prevailing green infrastructure for urban stormwater management, but it is less effective in dissolved nitrogen removal, especially for nitrate. The mechanism that governs the nitrate leaching and performance stability of stormwater biofilters is poorly understood. In this study, a water quality model was developed to predict the ammonium and nitrate dynamics in a biochar-pyrite amended stormwater biofilter.

Microbial community dynamics and metagenomics reveal the potential role of unconventional functional microorganisms in nitrogen and phosphorus removal biofilm system.

The conventional functional microorganisms for nitrogen and phosphorus removal, such as Nitrosomonas, Nitrobacter, Nitrospira and Candidatus Accumulibacter, were hotspots in past research. However, the role of diverse unconventional functional microorganisms was neglected. In this study, a biofilm system was developed to explore the potential role of unconventional functional microorganisms in nutrients removal.

Insights into simultaneous nitrogen and phosphorus removal in biofilm: The overlooked comammox Nitrospira and the positive role of glycogen-accumulating organisms.

Simultaneous nitrogen and phosphorus removal (SNPR) biofilm system is an effective wastewater treatment process. However, the understanding on the mechanism of functional microorganisms driving SNPR is still limited, especially the role of complete ammonia oxidation (comammox) Nitrospira and glycogen-accumulating organisms (GAO). In this study, a sequencing batch biofilm reactor (SBBR) performing SNPR was operated for 249 d.

Interface engineering-induced perovskite/spinel LaCoO/CoO heterostructured nanocomposites for efficient peroxymonosulfate activation to degrade levofloxacin.

Conventional perovskite oxides (ABO) tend to suffer from their inactive surfaces and limited active sites that reduce their catalytic activity and stability, while interface engineering is a facile modulating technique to boost the catalyst's inherent activity by constructing heterogeneous interfaces. In this study, perovskite/spinel LaCoO/CoO nanocomposites with heterogeneous interfaces were synthesized via sol-gel and in-situ gradient etching methods to activate peroxymonosulfate (PMS) for degrading levofloxacin (LEV). LaCoO on the surface was etched into spinel CoO, and LaCoO/CoO nanocomposites with two crystal structures of perovskite and spinel were successfully formed.

Pretreatment of septic tank wastewater by packed anaerobic baffled reactor: Pollutant degradation and microbial community succession in different compartments.

Anaerobic baffled reactor (ABR) is widely used in rural sewage treatment due to its unique structure, strong impact load resistance, and low energy consumption. However, there is a lack of research on pollutant degradation patterns and microbial community succession patterns in each compartment of ABR. In this study, a packed anaerobic baffled reactor (PABR) was constructed.

A long term study elucidates the relationship between media amendment and pollutant treatment in the stormwater bioretention system: Stability or efficiency?

Media amendment has been more and more frequently tested in stormwater bioretention systems for enhanced runoff pollutant treatment. However, few studies systematically evaluated the amended system over a long time span, which hindered the further optimization of the proposed amended media. In this study, biochar-pyrite system (PB), conventional sand system (SB), and biochar-woodchip system (WB) were established and operated for 26 months.

Assessing Intermediate Formation and Electron Competition during Thiosulfate-Driven Denitrification: An Experimental and Modeling Study.

There is increasing interest in thiosulfate-driven denitrification for low C/N wastewater treatment, but the denitrification performance varies with the thiosulfate oxidation pathways. Models have been developed to predict the products of denitrification, but few consider thiosulfate reduction to elemental sulfur (S), an undesirable reaction that can intensify electron competition with denitrifying enzymes. In this study, the model using indirect coupling of electrons (ICE) was developed to predict S formation and electron competition during thiosulfate-driven denitrification.

Corncob-pyrite bioretention system for enhanced dissolved nutrient treatment: Carbon source release and mixotrophic denitrification.

Solid biomass waste amendment and substrates modification in bioretention systems have been increasingly used to achieve effective dissolved nutrients pollution control in stormwater runoff. However, the risk of excess chemical oxygen demand (COD) leaching from organic carbon sources is often overlooked on most occasions. Pyrite is an efficient electron donor for autotrophic denitrification, but little is known about the efficacy of autotrophic-heterotrophic synergistic effect between additional carbon source and pyrite in bioretention.

Extracellular DNA plays a key role in the structural stability of sulfide-based denitrifying biofilms.

Sulfide-based biofilm processes are increasingly used for wastewater denitrification, yet little is known about the extracellular polymeric substance (EPS) composition of sulfide-oxidizing biofilms. This can have an important impact on biofilm mechanical strength and stability. In this research, the properties and roles of EPS components in biofilm stability were investigated.

New insight into ammonium oxidation processes and mechanisms mediated by manganese oxide in constructed wetlands.

Manganese oxide (MnOx) mediated ammonium (NH) oxidation in wetlands is receiving increased interest; however, the biochemical mechanisms of this process are vague due to only few studies have focused on terrestrial ecosystems. In this study, three subsurface flow constructed wetlands (CWs), high/low content of Mn-sand CW (HMn-CW/LMn-CW) and quartz sand CW (C-CWs), were set up to explore the extent of ammonium nitrogen (NH-N) removal and underlying mechanisms. According to the surface characteristics of Mn-sand, MnOx nanospheres were loaded as birnessite on the sand, while changes of the Mn/N contents indicated involvement of Mn-sand in NH-N removal.

Contribution of nitrification and denitrification to nitrous oxide turnovers in membrane-aerated biofilm reactors (MABR): A model-based evaluation.

As a novel and sustainable technology, membrane-aerated biofilm reactors (MABR) performing simultaneous nitrification and denitrification face the challenge of undesirable nitrous oxide (NO) emission. Thereby, a comprehensive analysis of NO turnover pathways and the affecting parameters in MABR are demanded for NO mitigation strategies. In this work, a mathematical model describing three NO turnovers pathways was studied to uncover the underlying mechanisms and the impacts of operational conditions on NO turnovers in MABR system performing simultaneous nitrification and denitrification.

Biochar-pyrite bi-layer bioretention system for dissolved nutrient treatment and by-product generation control under various stormwater conditions.

Bioretention system with modified media has been increasingly used to control dissolved nutrients in stormwater runoff. However, complicated removal processes and improper design have made most of them hardly achieve comprehensive dissolved nutrient removal and even show by-product generation problem, especially during extreme stormwater events. Here, a modified biochar-pyrite (FeS) bi-layer bioretention system was developed and tested under various stormwater conditions with conventional sand-based and woodchip-based bioretention systems as controls.

A Bayesian-SWMM coupled stochastic model developed to reconstruct the complete profile of an unknown discharging incidence in sewer networks.

Unknown illicit discharges from manufactories often contain toxic chemical matters that are detrimental to the receiving waterbody by deteriorating the performance of wastewater treatment plants. Numerical models that identify these sources and reconstruct the discharging profiles are highly desired for environment management purpose. In this study, a stochastic source identification model that couples Bayesian inference with SWMM is developed to reconstruct the profile of an instantaneous dumpling incidence in sewer networks.