Evidences of the sources of suspended sediments and ecological processes in the Yellow River Basin.

Terrestrial originated suspended sediments from the Yellow River are crucial to understand the sources of the suspended sediment and ecological processes in estuary. This study integrated physicochemical indices, stable isotopes and microbial communities to trace the origin of the suspended sediment, and investigated the importance of ecological processes in community assembly via the null model and neutral community model. Global data revealed that the dissolved and particle ratios of carbon and nitrogen obviously decreased from the headstream to the estuary.

Effect of organic matter on the environmental behavior of sulfur and heavy metals in mariculture sediments during the aging process.

Organic matter (OM) significantly impacts the environmental behavior of sulfur and heavy metals. In this study, the effects of OM on the migration and transformation of sulfur and heavy metals in mariculture sediments were investigated. The results indicated that baiting had a strong impact on the accumulation of acid volatile sulfur (AVS) (P < 0.

New insights into the sustainable use of co-pyrolyzed dredged sediment for the in situ remediation of Cd polluted sediments in coastal rivers.

The remediation of Cd-polluted sediment in coastal rivers is essential because of its potential hazards to river and marine ecosystems. Herein, a co-pyrolysis product of contaminated dredged sediment (S@BC) was innovatively applied to cap and immobilize Cd-contaminated sediment in coastal rivers in situ, and their remediation efficiencies, mechanisms, and microbial responses were explored based on a 360 d incubation experiment. The results showed that although S@BC immobilization and capping restrained sediment Cd release to the overlying water, S@BC capping presented a high inhibitory efficiency (66.

Nutrients in overlying water affect the environmental behavior of heavy metals in coastal sediments.

Excessive nutrients in aquatic ecosystems are the main driving factors for eutrophication and water quality deterioration. However, the influence of nutrients in overlying water on sediment heavy metals is not well understood. In this study, the effects of nitrate nitrogen (NO-N) addition and phosphate addition in the overlying water on the environmental behaviors of chromium (Cr), copper (Cu), and cadmium (Cd) in coastal river sediments were investigated.

Characteristics of plasma exosomes in drug-resistant tuberculosis patients.

Background: Increasing prevalence of drug-resistant tuberculosis (DR-TB) poses a major challenge to the early detection and effective control of tuberculosis (TB). Exosomes carrying proteins and nucleic acid mediate intercellular communication between host and pathogen including Mycobacterium tuberculosis. However, molecular events of exosomes indicating the status and development of DR-TB remain unknown.

Feasibility of soil and sludge standards for freshwater sediment pollutant determination and quality judgment.

The environmental standards of soil and sludge have been typically referenced for freshwater sediment determination and quality assessment, especially in some areas without sediment standards. The feasibility of determination method and quality standard of soils and sludge for freshwater sediment was investigated in this study. Fractions of heavy metals, nitrogen, phosphorus, and reduced inorganic sulfur (RIS) in different type of samples were determined, including freshwater sediments, dryland and paddy soils, and sludge with air-drying (AD) and freeze-drying (FD) treatment, respectively.

Co-pyrolysis with pine sawdust reduces the environmental risks of copper and zinc in dredged sediment and improves its adsorption capacity for cadmium.

Proper treatment of heavy metal-contaminated dredged sediment (DS) is crucial to avoid secondary pollution. Effective and sustainable technologies are desired for the treatment of Zn- and Cu-contaminated DS. Due to the advantages of low energy consumption and time saving, co-pyrolysis technology was innovatively applied to treat Cu- and Zn-polluted DS in this study, and the effects of the co-pyrolysis conditions on Cu and Zn stabilization efficiencies, potential stabilization mechanisms, and the possibility for resource utilization of co-pyrolysis product were also investigated.

Ecological and environmental risks of heavy metals in sediments in Dingzi Bay, South Yellow Sea.

As a special geographical location between rivers and oceans, coastal estuaries always face severe heavy metal contaminations, especially in semi-closed bay. In this study, the spatial distribution, chemical fraction, ecological risks, and potential sources of heavy metals (Pb, Cr, Cu, As, Cd, Zn, and Ni) in surface sediments and sediment cores were investigated in Dingzi Bay, Shandong Peninsula. The I values and modified potential ecological risk index (MRI) indicated that Cd and As presented high environmental risks in the surface and sediment cores.

Oxidative stress responses in two marine diatoms during acute n-butyl acrylate exposure and the toxicological evaluation with the IBR index.

n-Butyl acrylate (nBA), a typical hazardous and noxious substance (HNS), is the largest-volume acrylate ester used to produce various types of polymers. With the increasing volume of nBA subject to maritime transportation, its accidental leakage poses a great risk to the marine organisms. Therefore, it is necessary to evaluate the ecological risk of nBA in marine environments.

Dissolved oxygen drives the environmental behavior of heavy metals in coastal sediments.

In this study, the impacts of dissolved oxygen (DO) on dynamics concentrations of heavy metals (Cu, Cd, Cr, and Pb) from estuary sediments were investigated in a 49-day laboratory simulation. The exchange flux method, Bureau Communautaire de Référence (BCR) sequential extraction procedure, and risk assessment code (RAC) were used to analyze the behavior of heavy metals. The results indicated that oxic environments promoted the concentrations of Cu and Cd in overlying water compared to the anoxic environments.

In situ fabrication of gold nanoparticles into biocathodes enhance chloramphenicol removal.

The development of highly conductive biofilms is a key strategy to enhance antibiotic removal in bioelectrochemical systems (BESs) with biocathodes. In this study, Au nanoparticles (Au-NPs) were in situ fabricated in a biocathode ( biocathode) to enhance the removal of chloramphenicol (CAP) in BESs. The concentration of Au(III) was determined to be 5 mg/L.

Feasibility of source identification by DOM fingerprinting in marine pollution events.

Accurate source identification is the first step of pollution control in environmental emergency management, especially in marine pollution events. Dissolved organic matter (DOM) absorption and fluorescence (excitation-emission matrices, EEMs) analyses were applied to trace contaminant sources for a pollution event that occurred along the coast of Laizhou Bay, Bohai Sea. Parallel factor analysis (PARAFAC) of the EEMs identified four fluorescent components: terrestrial humic-like (C1), tryptophan-like (C2), and a mixture of terrestrial and marine humic-like (C3) and tyrosine-like (C4) components.

Efficacy of in situ active capping Cd highly contaminated sediments with nano-FeO modified biochar.

Effective remediation of Cd polluted sediment is imperative for its potential damages to aquatic ecosystem. Biochar (BC) and nano-FeO modified BC (nFeO@BC) were conducted to remedy Cd highly contaminated sediments, and their performances, applicable conditions, and mechanisms were investigated. After 60 d capping, both BC and nFeO@BC capping inhibited Cd release from sediment to overlying water and porewater (reduction rates >99%).

Conversion mechanisms between organic sulfur and inorganic sulfur in surface sediments in coastal rivers.

Geochemical processes of sulfur (S) in river aquatic systems play a crucial role in environmental evolution. In this study, the distributions and sources of reduced inorganic sulfur (RIS) and organic sulfur (OS) in coastal river surface sediments were investigated. The results indicated that OS dominated total S (80%), and OS (i.

Effects of suspended particular matters, excess PO, and salinity on phosphorus speciation in coastal river sediments.

Phosphorus (P) is an essential biogenic element in aquatic ecosystem, and its speciation in sediment may influence the water quality. The composition of P in suspended particular matters (SPM) and sediments were analyzed. Metal ions bonding PO and chelating organic P (OP) were explored by Visual MINTEQ simulation and infrared spectroscopy.

Remediation and its biological responses of Cd contaminated sediments using biochar and minerals with nanoscale zero-valent iron loading.

Remediation of Cd pollution in sediments is crucial for the safety of aquatic environments and human health. In this study, four effective, common, and low-cost remediation materials (zeolite, sepiolite, red mud (RM), and biochar (BC)) loaded with nanoscale zero-valent iron (nZVI) and themselves were employed to immobilize Cd in sediments. The effects of different materials on sediment properties, immobilization effectiveness, bacterial communities, enzyme activities, and dissolved organic matter (DOM) were investigated.

Attempt of basin-scale sediment quality standard establishment for heavy metals in coastal rivers.

Heavy metal sediment quality standards (SQSs) derived from sediment quality guidelines (SQGs) are crucial in risk evaluation and environmental management. However, the establishment of SQSs is quite complex, especially for heavy metals. This study attempted to establish basin-scale SQSs for Cd, Cu, Pb and Zn based on SQGs combined with water quality standards in two coastal rivers in North China, named Jiaolai River (JL) and Jiahe River (JR), respectively.

Effects of macro metals on alkaline phosphatase activity under conditions of sulfide accumulation.

Alkaline phosphatase (AP) is commonly found in aquatic ecosystems as an extracellular enzyme closely related to the biogeochemical cycling of phosphorus. Although the AP activity (APA) is conventionally thought to be a main response to PO starvation, significant effects of macro metal elements (Al, Fe, and Ca) and S on the APA were found in this study. The APA was reduced by Al primarily through the adsorption of the enzyme onto AlOOH colloids.

Effects of drying pretreatments on the analysis of the mercury fraction in sediments.

The geochemical fractions of heavy metals in sediments are crucial indexes for their mobility and bioavailability evaluations. However, different drying processes of sediment pretreatment could change metal geochemical fractions, especially for Hg, which is potentially volatile. In this study, the influence of pretreatment methods including oven-drying, air-drying, freeze-drying, and fresh sediments on the analysis of Hg fractions in sediments was investigated.

Distribution and risk assessment of trace metals in riverine surface sediments in gold mining area.

Recognizing the pollution characteristics and potential risks of trace metals in sediments are important to protect water ecosystem safety. In the present study, a systematic investigation was performed to assess the pollution and risk level of trace metals in river sediments located in the greatest gold production base in China. The geo-accumulation index was used to assess the contamination degree.

[Spatial Distribution, Source and Ecological Risk Assessment of Heavy Metals in the Coastal Sediments of Northern Dongying City].

Concentrations of seven heavy metals in the coastal sediments of the northern Dongying City were measured. The spatial distribution and sources of heavy metals were discussed and the ecological risk was assessed using sediment quality guidelines (SQGs) and the potential ecological risk index (PERI). The concentration ranges of Hg, As, Pb, Cd, Cr, Cu, and Zn were calculated as 0.

Integrated toxicity evaluation of metals in sediments of Jiaozhou Bay (China): Based on biomarkers responses in clam Ruditapes philippinarum exposed to sediment extracts.

To evaluate the integrated toxicity of metals in sediments of Jiaozhou Bay, we exposed clam (Ruditapes philippinarum) to sediments extracts obtained using of sediment extraction with deionised water adjusted to pH 4 which simulated the weak acidity in the digestive juice of clams and tested the selected biomarkers responses in clams for exposure over 15 days. At the same time, the contents of metals in sediments were assessed with method of the mean sediment quality guideline quotient (SQG-Q). The integrated biomarker response version 2 (IBR) was used to assess the integrated toxicity induced by metals in sediment extracts based on biomarkers response in clams: the results demonstrated that site S7 located in the mouth of Nanxin'an River show higher IBR values compared to the other sites.

Assessment of metal contamination in estuarine surface sediments from Dongying City, China: Use of a modified ecological risk index.

Surface sediments and clam Meretrix meretrix were collected from a northern estuarine region in Dongying City, China. Sediments were analysed for heavy metals (Hg, As, Cd, Cr, Cu, Pb, and Zn) and the clams were tested for metallothioneins (MTs) and lysosomal membrane stability (LMS). The heavy metal total concentrations decreased in the order of Cr>Zn>Cu>Pb>As>Cd>Hg.