Acyl-Homoserine Lactone Enhances the Resistance of Anammox Consortia under Heavy Metal Stress: Quorum Sensing Regulatory Mechanism.

Anaerobic ammonium oxidation (anammox) represents an energy-efficient process for the removal of biological nitrogen from ammonium-rich wastewater. However, the susceptibility of anammox bacteria to coexisting heavy metals considerably restricts their use in engineering practices. Here, we report that acyl-homoserine lactone (AHL), a signaling molecule that mediates quorum sensing (QS), significantly enhances the nitrogen removal rate by 24% under Cu stress.

Wet-dry or freeze-thaw alternation can regulate the impacts of farmland plastic pollution on soil bacterial communities and functions.

The persistence of farmland plastic pollution has raised significant concerns regarding its potential long-term impacts on soil health in the context of global climate change. However, there are still gaps in the understanding of the impacts of plastic residues on soil microbial communities and functions in agricultural environments under unstable and extreme climatic conditions. In this study, the effects of plastic residues (two types and three shapes) on farmland soil bacterial communities and functions across varying environmental conditions were investigated through microscopic experiments.

Selectively recovering rare earth elements with carboxyl immobilized metal-organic framework from ammonium-rich wastewater.

The material with high adsorption capacity and selectivity is essential for recovering rare earth elements (REE) from ammonium (NH-N)-rich wastewater. Although the emerging metal-organic framework (MOF) has gained intensive attention in REE recovery, there are scientific difficulties unsolved regarding restricted adsorption capacity and selectivity, hindering its extensive engineering applications. In this work, a diethylenetriamine pentaacetic (DTPA)-modified MOF material (MIL-101(Cr)-NH-DTPA) was prepared through an amidation reaction.

[Start-up and Recovery Performance of ANAMMOX Reactors Under Long-term Starvation].

The application of ANAMMOX technology is constrained by sluggish growth and difficulty in enriching ANAMMOX bacteria. Long-term starvation of functioning bacteria due to limited substrate supply makes the steady operation of ANAMMOX reactors more difficult. Re-examining the start-up and recovery performance of the ANAMMOX reactor and identifying its resistance mechanism are important from the standpoint of long-term starvation.

Direct Determination of Absolute Radical Quantum Yields in Hydroxyl and Sulfate Radical-Based Treatment Processes.

The absolute radical quantum yield () is a critical parameter to evaluate the efficiency of radical-based processes in engineered water treatment. However, measuring is fraught with challenges, as current quantification methods lack selectivity, specificity, and anti-interference capabilities, resulting in significant error propagation. Herein, we report a direct and reliable time-resolved technique to determine at pH 7.

Electrochemically selective ammonium recovery from wastewater via coupling hydrogen bonding and charge storage.

Electrochemical ammonium (NH) storage (EAS) has been established as an efficient technology for NH recovery from wastewater. However, there are scientific difficulties unsolved regarding low storage capacity and selectivity, restricting its extensive engineering applications. In this work, electrochemically selective NH recovery from wastewater was achieved by coupling hydrogen bonding and charge storage with self-assembled bi-layer composite electrode (GO/VO).

Characterization of the microplastic photoaging under the action of typical salt ions of biological nitrogen removal processes.

Microplastics (MPs) are one of the most prevalent and diverse contaminants, and wastewater treatment plants are significant MP aggregators. Controlling the pollution caused by microplastics requires an understanding of how they age. The properties of the MPs photoaging process under the influence of salt ions typical of biological nitrogen elimination processes were disclosed in this work.

Dosing with pyrite significantly increases anammox performance: Its role in the electron transfer enhancement and the functions of the Fe-N-S cycle.

Anaerobic ammonium oxidation (anammox) represents an energy-efficient process for biological nitrogen removal from ammonium-rich wastewater. However, there are mechanistic issues unsolved regarding the low microbial electron transfer and undesired accumulation of nitrate in treated water, limiting its widespread engineering applications. We found that the addition of pyrite (1 g L reactor), an earth-abundant iron-bearing sulfide mineral, to the anammox system significantly improved the nitrogen removal rate by 52% in long-term operation at a high substrate shock loading (3.

[Removal Characteristics of Four Typical Antibiotics in Denitrification System].

Wastewater treatment plants are an important gathering place for antibiotics, where denitrification plays a vital role in biological nitrogen removal. In order to explore the removal characteristics of antibiotics in a denitrifying sludge system, norfloxacin (NOR), oxytetracycline (OTC), sulfamethoxazole (SMX), and trimethoprim (TMP) were selected to investigate their transformation under different carbon source conditions in a denitrification system. The contribution of adsorption and biodegradation for antibiotic removal was also evaluated in this study.

Understanding the slight inhibition of high As(III) stress on nitritation process: Insights from arsenic speciation and microbial community analyses.

Nitritation process with ammonia-oxidizing bacteria frequently suffers inhibition from heavy metals in industrial wastewater treatment. However, As(III), one of the most toxic metalloids, showed slight inhibition though the arsenic accumulation content in the sludge reached 91.8 mg L in this study.

Distinct membrane fouling characteristics of anammox MBR with low NO-N/NH-N ratio.

The bacterial growth and death, and extracellular polymeric substances (EPS) and soluble microbial products (SMP) in aerobic membrane bioreactor (MBR) cause severe membrane fouling. Anammox bacteria grow slowly but produce much EPS and SMP. Therefore, the membrane fouling characteristic of anammox MBR is still indistinct.

Hydroxylamine addition enhances fast recovery of anammox activity suffering Cr(VI) inhibition.

Hydroxylamine (NHOH), one of the most important intermediates of anammox was employed to test the recovery performance because of its stimulation to anammox bacteria. Batch test indicated simultaneous addition of 1.83 ~ 9.

Development and simulation of a struvite crystallization fluidized bed reactor with enhanced external recirculation for phosphorous and ammonium recovery.

Recovering nitrogen and phosphorus from waste water in the form of struvite is an effective way to recycle resources. The insufficient purity of the resulting struvite and the large loss of nitrogen and phosphorus are the challenges at present. Therefore, it is urgent to develop innovative method in struvite crystallization process for efficient nitrogen and phosphorus recovery.

Performance, microbial community and inhibition kinetics of long-term Cu stress on an air-lift nitritation reactor with self-recirculation.

Biological nitrogen removal process could be affected due to the presence of heavy metals owing to their toxicity and accumulation in the sludge. In this study, the impact of Cu shock on a long-term nitritation operation was investigated in an air-lift reactor with self-recirculation. Both the dynamics of microbial community and inhibition kinetics under Cu stress were ascertained.

Long-term domestication to Mn stresses alleviates the inhibition on anammox process.

Heavy metals such as Mn are common contaminants in ammonium-rich wastewater. The information of Mn effect on anammox process needs further investigation. The short- and long-term effects of Mn on anammox were explored by anammox granular sludge.

Quantitative determination of cavitation formation and sludge flotation in Anammox granules by using a new diffusion-reaction integrated mathematical model.

The granulation of anaerobic ammonium oxidation (Anammox) biomass plays a key role in high rate performance of upflow-type Anammox reactors. However, the formation of cavitation inside granules may result in sludge flotation problem, which negatively affects the operation stability. For quantitative evaluation of the Anammox granules flotation in upflow reactors, an integrated mathematical model was formulated based on the principles that the limitation of substrate diffusion would result in bacterial starvation, lysis and subsequently aiding the formation of cavitation in the inner zone of granules.

Synthesis of core-shell UiO-66-poly(m-phenylenediamine) composites for removal of hexavalent chromium.

The present research developed a direct in situ heterogeneous method to synthesize UiO-66-poly(m-phenylenediamine) core-shell nanostructures by inducing assembly of m-phenylenediamine radical on UiO-66 surfaces. The strong interaction between negative charged UiO-66 and positive radical from the oxidation of monomer is the major driving force. The produced UiO-66-poly(m-phenylenediamine) composites exhibited a distinct core-shell morphology with controllable surface features.

Elucidating the effect of mixing technologies on dynamics of microbial communities and their correlations with granular sludge properties in a high-rate sulfidogenic anaerobic bioreactor for saline wastewater treatment.

In this study, three lab-scale anaerobic sulfidogenic bioreactors were operated independently using three different mixing modes (hydraulic, mechanical and pneumatic). One-way ANOVA test indicated various performance parameters (e.g.

Effect of scrubbing by NaClO backwashing on membrane fouling in anammox MBR.

NaClO based chemically enhanced backwash (CEB) is often administered to maintain membrane permeability during the operation of MBR. However, the effect and working mechanism of NaClO concentrations in CEB were rarely investigated. The current investigation examined the changes in membrane resistance, permeate production and membrane morphology with or without CEB in an anammox MBR to reveal the scrubbing effect of different NaClO concentrations (0-596 mg/L).

The long-term effects of hexavalent chromium on anaerobic ammonium oxidation process: Performance inhibition, hexavalent chromium reduction and unexpected nitrite oxidation.

The toxicity of hexavalent chromium (Cr(VI)) is one of the challenges in implementing Anammox process to ammonium-rich wastewater treatment. However, the response of Anammox process to Cr(VI) stress and the inhibition mechanism remain unclear. Here, two Anammox UASB reactors were operated for 285 days under different Cr(VI) stresses.

Mechanistic Study on the Role of Soluble Microbial Products in Sulfate Radical-Mediated Degradation of Pharmaceuticals.

The role of soluble microbial products (SMP), the most important component of effluent organic matter from municipal wastewater treatment plants, in sulfate radical (SO)-based advanced oxidation technologies (AOTs) remains substantially unclear. In this study, we first utilized a suite of macro- and microanalytical techniques to characterize the SMP from a membrane bioreactor for its fundamental molecular, spectroscopic, and reactivity properties. The degradation kinetics of three representative pharmaceuticals (i.

Insights into the role of extracellular polymeric substances in Zn adsorption in different biological sludge systems.

The adsorption behavior of Zn in four different biological sludge systems, i.e. activated sludge, denitrification sludge, short-cut nitrification sludge, and anammox granules, was investigated.

Short-term effects of nanoscale Zero-Valent Iron (nZVI) and hydraulic shock during high-rate anammox wastewater treatment.

The stability and resilience of an anaerobic ammonium oxidation (anammox) system under transient nanoscale Zero-Valent Iron (nZVI) (50, 75 and 100 mg L), hydraulic shock (2-fold increase in flow rate) and their combination were studied in an up-flow anaerobic sludge blanket reactor. The response to the shock loads can be divided into three phases i.e.

Corrigendum to "Start-Up Characteristics of a Granule-Based Anammox UASB Reactor Seeded with Anaerobic Granular Sludge".

[This corrects the article DOI: 10.1155/2013/396487.].