Reductive Dissolution Mechanisms of Manganese Oxide Mediated by Algal Extracellular Organic Matter and the Effects on 17α-Ethinylestradiol Removal.

Reductive dissolution of manganese oxide (MnO) is a major process that improves the availability of manganese in natural aquatic environments. The extracellular organic matter (EOM) secreted by algae omnipresent in eutrophic waters may affect MnO dissolution thus the fate of organic micropollutants. This study investigates the mechanisms of MnO reductive dissolution mediated by EOM and examines the effects of this process on 17α-ethinylestradiol degradation.

Investigation of SrBO:Tm luminescence for temperature imaging with high sensitivity based on time-resolved luminescence.

In recent years, with the growing demand for non-contact and real-time optical temperature measurements, it has become imperative to develop new luminescent thermometry materials as well as novel temperature detection schemes with higher sensitivity. In this work, a series of SrBO:Tm ( = 0.001-0.

Toxic mechanisms of the antiviral drug arbidol on microalgae in algal bloom water at transcriptomic level.

Increasing antivirals in surface water caused by their excessive consumption pose serious threats to aquatic organisms. Our recent research found that the input of antiviral drug arbidol to algal bloom water can induce acute toxicity to the growth and metabolism of Microcystis aeruginosa, resulting in growth inhibition, as well as decrease in chlorophyll and ATP contents. However, the toxic mechanisms involved remained obscure, which were further investigated through transcriptomic analysis in this study.

Algal Extracellular Organic Matter Induced Photochemical Oxidation of Mn(II) to Solid Mn Oxide: Role of Mn(III)-EOM Complex and Its Ability to Remove 17α-Ethinylestradiol.

Photosensitizer-mediated abiotic oxidation of Mn(II) can yield soluble reactive Mn(III) and solid Mn oxides. In eutrophic water systems, the ubiquitous algal extracellular organic matter (EOM) is a potential photosensitizer and may have a substantial impact on the oxidation of Mn(II). Herein, we focused on investigating the photochemical oxidation process from Mn(II) to solid Mn oxide driven by EOM.

The environmental risks of antiviral drug arbidol in eutrophic lake: Interactions with Microcystis aeruginosa.

The environmental risks resulting from the increasing antivirals in water are largely unknown, especially in eutrophic lakes, where the complex interactions between algae and drugs would alter hazards. Herein, the environmental risks of the antiviral drug arbidol towards the growth and metabolism of Microcystis aeruginosa were comprehensively investigated, as well as its biotransformation mechanism by algae. The results indicated that arbidol was toxic to Microcystis aeruginosa within 48 h, which decreased the cell density, chlorophyll-a, and ATP content.

Occurrence and cycle of dissolved iron mediated by humic acids resulting in continuous natural photodegradation of 17α-ethinylestradiol.

17α-ethinylestradiol (EE2), a synthetic endocrine-disrupting chemical, can degrade in natural waters where humic acids (HA) and dissolved iron (DFe) are present. The iron is mostly bound in Fe(III)-HA complexes, the formation process of Fe(III)-HA complexes and their effect on EE2 degradation were explored in laboratory experiments. The mechanism of ferrihydrite facilitated by HA was explored with results indicating that HA facilitated the dissolution of ferrihydrite and the generation of Fe(III)-HA complexes with the stable chemical bonds such as C-O, CO in neutral, alkaline media with a suitable Fe/C ratio.

Sunlight-induced degradation of COVID-19 antivirals arbidol in natural aquatic environments: Mechanisms, pathways and toxicity.

Insights into COVID-19 antivirals' environmental fate and ecological risk are urgently required due to their increasing concentrations in aquatic environments, which have rarely been studied. Herein, we first investigated the photochemical transformation and the resulting alterations in toxicity of arbidol, an antiviral drug with relatively higher toxicity. The photolysis of arbidol was rapid with a rate constant of 0.

Dynamic simulation of a motor longitudinally mounted on a centralized electric drive systems for pure electric vehicles under torque ripple and transmission error excitations.

The dynamic characteristics of electric drive systems are crucial in electric vehicles. Based on the dynamic finite element method and previous studies, this study proposes and analyzes a new mathematical model for a motor longitudinally mounted on a centralized electric drive system of a pure electric vehicle. First, we analyze the largest torque ripple of a fractional slot concentrated winding inner-mounted permanent magnet synchronous motor designed for commercial electric vehicles.

Investigation of the luminescence properties and energy transfer mechanisms in GdTaO:Bi,Eu phosphors for their potential application in full-spectrum WLEDs.

In recent years, there has been increasing effort devoted to the development of single-phase white phosphors due to drawbacks such as severe reabsorption and color deviation in traditional white light-emitting diodes (WLEDs). A new feasible strategy has emerged for achieving white light emission through the Bi-Eu energy transfer in suitable single-phase phosphors. Therefore, a series of GdTaO:Bi and GdTaO:0.

Variation in photochemical properties of dissolved black carbon during bio-transformation and iron mineral fractionation process.

The excellent photochemical properties of dissolved black carbon (DBC) have been proven to be a significant contributor to the removal of organic pollutants in environment. However, the photochemical properties of DBC will inevitably be changed during biotic and abiotic processes. Herein, the structures and compositions of DBC during bio-transformation and goethite adsorption processes were comprehensively studied, and their corresponding photochemical properties were also evaluated.

Algal organic matter and dissolved Mn cooperatively accelerate 17α-ethinylestradiol photodegradation: Role of photogenerated reactive Mn(III).

Algal extracellular organic matter (EOM), a major fraction of the dissolved organic matter found in eutrophic plateau lakes, can act as a photosensitizer to drive the abiotic oxidation of Mn(II). This process has the potential to generate reactive Mn(III) and influence the fate of organic pollutants. In this study, the photodegradation of 17α-ethinylestradiol (EE2) in the presence of Mn(II) and EOM was investigated with emphasis on the photogeneration mechanism of Mn(III).

The photolytic behavior of COVID-19 antivirals ribavirin in natural waters and the increased environmental risk.

Increasing drug residues in aquatic environments have been caused by the abuse of antivirals since the global spread of the COVID-19 epidemic, whereas research on the photolytic mechanism, pathways and toxicity of these drugs is limited. The concentration of COVID-19 antivirals ribavirin in rivers has been reported to increase after the epidemic. Its photolytic behavior and environmental risk in actual waters such as wastewater treatment plant (WWTP) effluent, river water and lake water were first investigated in this study.

The efficient treatment of mature landfill leachate using tower bipolar electrode flocculation-oxidation combined with electrochemical biofilm reactors.

Mature landfill leachate contains high concentrations of organic and inorganic compounds that inhibit the performance of conventional biological treatment. Nowadays, few single treatment techniques could fulfill the requirements of cleaning mature landfill leachate. In this study, a tower bipolar electrode flocculation-oxidation (BEF-O) reactor and an electrochemical biofilm reactor (EBR) combine device was constructed to effectively treat mature landfill leachate.

Photoaging mechanisms of microplastics mediated by dissolved organic matter in an iron-rich aquatic environment.

As emerging pollutants, microplastics (MPs) have aroused worldwide concern due to their ubiquitous distribution, environmental persistence, and potential ecological risks. However, the ageing mechanisms, environmental behaviours and risks of photoaged MPs mediated by environmental factors remain obscure. Herein, systems containing a light source, humic acid (HA) and Fe were established to investigate the natural photoaging process of MPs including polyvinyl chloride (PVC) and polyethylene terephthalate (PET).

The desorption mechanism of dissolved organic matter on pollutants and the change of biodiversity during sediment dredging.

Sediment dredging is an effective means to control the endogenous pollution of lakes, which could significantly change the concentration and composition of organic matter, especially dissolved organic matter (DOM) in the lake. DOM is particularly important for the release of endogenous pollutants, which will inevitably bring an impact on aquatic biodiversity. Nevertheless, in recent research little attention has been paid to the desorption mechanism of DOM on pollutants and the change of biodiversity during dredging.

Assessment technologies of rail systems' structural adequacy - A review from mechanical engineering perspectives.

The structural adequacy challenges of railroad track structures have received considerable attention globally. Track defects and failures due to weak strength and buckling effect account for one-third of all railroad accidents. The current paper provides a comprehensive study of the recent work on the structural adequacy/bearing capacity of rail systems from mechanical engineering perspectives; existing techniques for track stiffness/modulus evaluations, including standstill and continuous methods.

The distribution and risk of microplastics discharged from sewage treatment plants in terrestrial and aquatic compartment.

Many microplastics (MPs) were produced in daily life, which would enter sewage treatment plants (STPs) with the wastewater. Although the STPs has a good interception effect on these MPs, there will still be a part of MPs entering the environment with the effluent and sludge treatment, causing a certain ecological risk. This study investigated the abundance, characteristics and retention of MPs in different STPs, as well as the ecological risks caused by MPs entering the environment.

The synthesis of an amended membrane coated with graphene oxide and dopamine and guanidyl-based modifier and its antifouling properties.

The membrane fouling issue has aroused great concern. To improve their antifouling properties, surface grafting with oxidative deposition were employed to amend a polyvinylidene fluoride (PVDF) membrane. The modifiers were amino-modified graphene oxide (AMGO), dopamine (DPA) and 1,3-diaminoguanidine hydrochloride (DAGH).