Publications by authors named "Xiaochi Feng"

The dissemination of antibiotic resistance genes (ARGs) poses global environmental issues, and plasmid-mediated conjugation contributes substantially to the spread of ARGs. Quorum sensing (QS), an important cell-cell communication system that coordinates group behaviors, has potential as a feasible regulation pathway to inhibit the conjugation process. We examined the promoting effects of QS signal on conjugation, and this study is the first to report that QS inhibitors 2(3H)-benzofuranone and acylase I effectively repressed conjugation frequency of RP4 plasmid to 0.

View Article and Find Full Text PDF

In recent years, the peracetic acid (PAA)-based advanced oxidation process (AOPs) has garnered significant attention in the field of water treatment due to rapid response time and environmentally-friendliness. The activation of PAA systems by diverse carbon-based materials plays a crucial role in addressing emerging environmental contaminants, including various types, structures, and modified forms of carbon materials. However, the structural characteristics and structure-activity relationship of carbon-based materials in the activation of PAA are intricate, while the degradation pathways and dominant active species exhibit diversity.

View Article and Find Full Text PDF

Metal-based catalytic materials exhibit exceptional properties in degrading emerging pollutants within Fenton-like systems. However, the potential risk of metal leaching has become pressing environmental concern. This study addressed scientific issues pertaining to the leaching behavior and control strategies for metal-based catalytic materials.

View Article and Find Full Text PDF
Article Synopsis
  • Overusing antibiotics has led to their presence in water, affecting tiny living things that help remove pollution.
  • A study found that a specific antibiotic called ciprofloxacin (CIP) made it much harder for these helpers, known as denitrifiers, to do their job, leading to more pollution emissions.
  • The denitrifiers tried to protect themselves from damage caused by CIP, using special pathways for energy, but they still couldn't completely stop the harm from the antibiotic.
View Article and Find Full Text PDF
Article Synopsis
  • Biodenitrification is crucial for cleaning nitrogen-contaminated water, but low carbon-to-nitrogen (C/N) ratios hinder its effectiveness and lead to harmful byproducts.
  • A new material, β-cyclodextrin-functionalized biochar (BC@β-CD), was developed to improve denitrification performance at low C/N ratios, increasing nitrate reduction and decreasing nitrite and nitrous oxide emissions.
  • The study found that BC@β-CD enhances key metabolic pathways and boosts the generation of electron donors, significantly increasing glucose utilization for denitrification, demonstrating its potential use in wastewater treatment.
View Article and Find Full Text PDF
Article Synopsis
  • * D1 demonstrated excellent growth and nitrate removal capabilities, achieving over 96% total nitrogen removal without producing harmful intermediate nitrogen compounds like nitrite and nitrous oxide.
  • * Compared to other aerobic denitrifying microbes, D1 showed higher efficiency and enzyme activity, indicating its strong potential for treating nitrogen-rich wastewater.
View Article and Find Full Text PDF

Heterogeneous peroxymonosulfate (PMS) treatment is recognized as an effective advanced oxidation process (AOP) for the treatment of organic contaminants. Quantitative structure-activity relationship (QSAR) models have been applied to predict the oxidation reaction rates of contaminants in homogeneous PMS treatment systems but are seldom applied in heterogeneous treatment systems. Herein, we established QSAR models updated with density functional theory (DFT) and machine learning approaches to predict the degradation performance for a series of contaminants in heterogeneous PMS systems.

View Article and Find Full Text PDF

The regulation of bacterial quorum sensing (QS) has been used to inhibit biofouling in wastewater treatment plants and the formation of biofilms. In contrast to traditional QS regulation strategies, this study aimed to obstruct the transmembrane transport process of QS signals to decrease their extracellular accumulation. Three phytochemicals, astragaloside IV, eugenol, and baicalin were selected, their effects on biofilm formation by Pseudomonas aeruginosa PA14 were studied, and the mechanisms determined.

View Article and Find Full Text PDF

To preserve the water resources, this study has analyzed the ecotoxicity and antibiotic resistance genes (ARGs) induction capacity of sulfadiazine degradation intermediates resulting from persulfate activation oxidation enhanced by ultraviolet, ultrasound and microwave. The five degradation pathways caused by the contribution discrepancy of electron transfer and singlet oxygen (O) and variations in the ecotoxicity of different degradation products were analyzed. Microcosm experiment exhibited that the microbial community in actual water changed significantly with SDZ and degradation intermediates, in which the dominant genera were Aeromonas, Cupriavidus, Elizabethkingia and Achromobacter.

View Article and Find Full Text PDF

Data-driven approaches that make timely predictions about pollutant concentrations in the effluent of constructed wetlands are essential for improving the treatment performance of constructed wetlands. However, the effect of the meteorological condition and flow changes in a real scenario are generally neglected in water quality prediction. To address this problem, in this study, we propose an approach based on multi-source data fusion that considers the following indicators: water quality indicators, water quantity indicators, and meteorological indicators.

View Article and Find Full Text PDF
Article Synopsis
  • Current research explores how adding heteroatoms like nitrogen and sulfur can enhance the activity of catalysts in peroxymonosulfate (PMS) systems, although the exact mechanisms are not fully understood.
  • In the study, nitrogen and sulfur were doped into Co@rGO material, which significantly improved the degradation of tetracycline (TC) while altering the activation mechanism; nitrogen did not change the activation process, but sulfur transformed the oxidation pathway into a more efficient non-radical pathway.
  • Density functional theory (DFT) calculations demonstrated that the presence of sulfur (CoS) increased the energy barrier for PMS interaction compared to cobalt oxide (CoO), leading to less activation of the radical pathway and overall better stability
View Article and Find Full Text PDF

The main purpose of this study was to explore the pretreatment process of corn starch wastewater (CSW) and engineered microalgae cultivation strategy to improve the nutrient recovery from wastewater and the yield of microalgae lutein. One-stage enzymatic hydrolysis utilizing α-amylase and glucoamylase simultaneously was established to efficiently harvest a maximum concentration of reducing sugar content of 7.26 g/L from CSW in 50 min.

View Article and Find Full Text PDF
Article Synopsis
  • Scientists are working on a new method using special materials called CoO and rGO to help break down a harmful substance called tetracycline (TC) faster and more efficiently.
  • When they mixed these materials with a chemical called PMS, they found that they could completely remove 50 mg/L of tetracycline in just 20 minutes!
  • The study showed that the combination of two types of active materials worked together in a unique way to make the breakdown of tetracycline happen even better, making this method promising for cleaning up pollutants.
View Article and Find Full Text PDF

Municipal sludge disposal and recycle has become a prominent research theme. In this study, a sequential process for integral treatment of municipal sludge was primarily presented, combining acid leaching, anion exchange and aerobic composting. The aim of the process was to remove chromium (Cr) from the sludge and reuse the sludge as manure.

View Article and Find Full Text PDF

Short chain carboxylic acids (SCCAs) production is one of the primary ways to recycle excess sludge (ES). However, the high cost for the SCCAs separation/extraction due to its complete miscibility in water hinders the practical application of SCCAs and the popularization of this recycling way. To overcome this barrier, this study performed an emerging chain elongation (CE) technology to upgrade the SCCAs-rich sludge fermentation broth into the highly hydrophobic medium chain carboxylic acids (MCCAs).

View Article and Find Full Text PDF

Metabolic uncouplers inhibit biofilm and biofouling formation in membrane bioreactor (MBR) systems, which have been considered as a potential biofouling control alternative. To better understand the inhibitory mechanism of uncoupler on biofouling, this study investigated the impact of the uncoupler 3, 3', 4', 5-tetrachlorosalicylanilide (TCS) on biofilm formation of B. subtilis in different development stages.

View Article and Find Full Text PDF

Herein, a novel innovative lipid co-extraction strategy using the biodiesel-producing microalga Chlorella pyrenoidosa and planktonic cladoceran Daphnia was proposed. Co-extraction occurred as Daphnia ingested and digested microalgal cells in a pre-treatment process; thereafter, lipids from these organisms were extracted. Composition of fatty acids from C.

View Article and Find Full Text PDF

The cultivation of microalgae in municipal wastewater not only purifies the wastewater but also transforms nutrients into biomass that contains high-value lipids. In this study, conventional static bottom-magnetic field (bottom-MF) equipment and cost-effective bypass-magnetic field (bypass-MF) equipment were designed and independently coupled with a microalgae-wastewater system in different positions to evaluate the effect of magnetic field (MF) on microalgae biomass production and lipid accumulation. When the MF equipment was applied in the wastewater pretreatment unit, the bottom-MF pretreatment mode exhibited a more beneficial effect on subsequent biomass and lipid accumulation.

View Article and Find Full Text PDF

Biofouling is a limiting bottleneck in the development of membrane bioreactor (MBR) since the birth of this technology. Recently, the biofouling control strategy based on interfering with the bacterial quorum sensing (QS) system is highly desirable for biofouling control in MBR. In this study, three lab-scale parallel MBR systems were operated over 100 days to investigate the inhibitory effect of a metabolic uncoupler (3,3',4',5-tetrachlorosalicylanilide, TCS) on biofouling and the potential mechanism for biofouling control.

View Article and Find Full Text PDF

As a widely used detergent, anionic surfactant linear alkylbenzene sulfonates (LAS) is a common toxic pollutant in wastewater. In this study, Pseudomonas sp. strain H6 was isolated from activated sludge and municipal wastewater, which had good degradation effect on LAS.

View Article and Find Full Text PDF

In this work, a novel flocculation process by using nano-FeO coated with polyethyleneimine (FeO@PEI) as magnetic seeds was developed to harvest the microalgae cultivated in urban sewage. Experiment results indicated that the harvest efficiency of Chlorella pyrenoidosa (0.5 g/L) was 98.

View Article and Find Full Text PDF

Metal-organic frameworks (MOFs) have attracted widespread concerns in the photocatalysis research. However, MOFs-based photocatalyts for antibiotics treatment are still very limited. There are also few reports on selecting MOFs as supports to regulate the morphology of Bismuthoxyhalides.

View Article and Find Full Text PDF

Ethanol and lactate are considered suitable electron donors (EDs) for chain elongation (CE); however, their respective shortcomings still limit the substrate conversion ratio and medium chain fatty acid (MCFA) production. To address this limitation, different EDs and electron acceptors (EAs) were combined to compare their CE performances, and to investigate whether the combination of ethanol and lactate could further enhance the MCFA production based on the complementary characteristics of ethanol and lactate. The results verified, for the first time, ethanol and lactate as the co-EDs formed a cooperative relationship to largely promote the conversion of substrates into MCFA.

View Article and Find Full Text PDF

Visible light-driven conversion of soluble U(VI) to slightly soluble U(IV) has been regarded as a efficient and environmentally friendly technology to deal with uranium containing wastewater. In this paper, we attempted to use photocatalytic technology to reduction U(VI) from aqueous solution by constructing a highly efficient photocatalysts. The novel Sn-doped InS microspheres photocatalyst were synthesized for the first time by a simple hydrothermal method, and characterized with various analytical and spectroscopic techniques to determine their structural, morphological, compositional, optical and photocatalytic properties.

View Article and Find Full Text PDF

In order to understand the inhibitory mechanism of metabolic uncoupler in biofilm, this study investigated the effect of TCS on biofilm formation, flocculability, surface characteristics and thermodynamic properties. An optimal concentration of TCS, a metabolic uncoupler, was observed to substantially inhibit biofilm formation and the secretion of extracellular polymeric substances (EPS). The effect of TCS on the zeta potential and flocculability of bacterial suspension implied the addition of 100 μg L TCS increased the net negative charge of cell surface which induced the reduction of flocculability.

View Article and Find Full Text PDF