Predicting criteria continuous concentrations of metals or metalloids for protecting marine life by use of quantitative ion characteristic-activity relationships-species sensitivity distributions (QICAR-SSD).

Marine pollution by metals has been a major challenge for ecological systems; however, water quality criteria (WQC) for metals in saltwater is still lacking. Especially from a regulatory perspective, chronic effects of metals on marine organisms should receive more attention. A quantitative ion characteristic-activity relationships-species sensitivity distributions (QICAR-SSD) model, based on chronic toxicities for eight marine organisms, was established to predict the criteria continuous concentrations (CCCs) of 21 metals.

Effects of monovalent and divalent metal cations on the aggregation and suspension of FeO magnetic nanoparticles in aqueous solution.

There has been limited research investigating how the mechanisms of aggregation of magnetic nanoparticles (MNPs) are affected by inorganic ions. In this study, Na, Mg, Ca, Sr and Ba were selected to systematically study the aggregation mechanisms of FeO MNPs. The results indicated that divalent cations more significantly affected the stabilities of MNPs than Na at low concentrations (e.

An enantiomer-based virtual screening approach: Discovery of chiral organophosphates as acetyl cholinesterase inhibitors.

Chiral organophosphates (OPs) have been used widely around the world, very little is known about binding mechanisms with biological macromolecules. An in-depth understanding of the stereo selectivity of human AChE and discovering bioactive enantiomers of OPs can decrease health risks of these chiral chemicals. In the present study, a flexible molecular docking approach was conducted to investigate different binding modes of twelve phosphorus enantiomers.

Long-Term Trends in Acid Neutralizing Capacity under Increasing Acidic Deposition: A Special Example of Eutrophic Taihu Lake, China.

While North America and Europe have been recovering from acidification, China is experiencing impacts of acid deposition. The Taihu region is a seriously impacted area by acid rain in China, with the average rainfall pH < 5. However, the acid neutralizing capacity (ANC) and pH of Taihu Lake have significantly increased over the past 60 years (p < 0.

National investigation of semi-volatile organic compounds (PAHs, OCPs, and PCBs) in lake sediments of China: Occurrence, spatial variation and risk assessment.

In this study, a large scale investigation of semi-volatile organic compounds (SVOCs) in sediments from 52 lakes, located in five geographic regions across China, was conducted to assess sediment quality in terms of organic contaminants. Concentrations of polycyclic aromatic hydrocarbons (PAHs), organochlorine pesticides (OCPs), and polychlorinated biphenyls (PCBs) in sediment were found to range between 17.00-6,633, 0.

Forms and Lability of Phosphorus in Algae and Aquatic Macrophytes Characterized by Solution P NMR Coupled with Enzymatic Hydrolysis.

Solution Phosphorus-31 nuclear magnetic resonance (P NMR) spectroscopy coupled with enzymatic hydrolysis (EH) with commercially available phosphatases was used to characterize phosphorus (P) compounds in extracts of the dominant aquatic macrophytes and algae in a eutrophic lake. Total extractable organic P (P) concentrations ranged from 504 to 1643 mg kg and 2318 to 8395 mg kg for aquatic macrophytes and algae, respectively. Using P NMR spectroscopy, 11 P species were detected in the mono- and diester region.

Using solid C NMR coupled with solution P NMR spectroscopy to investigate molecular species and lability of organic carbon and phosphorus from aquatic plants in Tai Lake, China.

Forms and labilities of plant-derived organic matters (OMs) including carbon (C) and phosphorus (P) were fundamental for understanding their release, degradation and environmental behaviour in lake ecosystems. Thus, solid C and solution P nuclear magnetic resonance (NMR) spectroscopy were used to characterize biomass of six aquatic plants in Tai Lake, China. The results showed that carbohydrates (61.

Identification, Tissue Distribution, and Bioaccumulation Potential of Cyclic Perfluorinated Sulfonic Acids Isomers in an Airport Impacted Ecosystem.

The use of cyclic perfluoroalkyl acids as anticorrosive agents in hydraulic fluids remains a poorly characterized source of organofluorine compounds to the environment. Here, we investigated the presence of perfluoroethylenecyclohexanesulfonate (PFECHS) isomers in environmental samples for the first time using a combination of high resolution and tandem mass spectrometry. Five distinct peaks attributed to different isomers of PFECHS and perfluoropropylcyclopentanesulfonate (PFPCPeS) were identified in environmental samples.

Estrogenic compound profiles in an urbanized industry-impacted coastal bay and potential risk assessment by pollution indices and multivariative statistical methods.

The occurrence and distribution of target estrogenic compounds in a highly urbanized industry-impacted coastal bay were investigated, and contamination profiles were evaluated by estimating total estradiol equivalents (∑EEQs) and risk quotients (RQs). Phenolic compounds were the most abundant xenoestrogens, but seldom showed contribution to the ∑EEQs. The diethylstilbestrol (DES) and 17α-ethinylestradiol (EE2) were the major contributors followed by 17β-estradiol (E2) in comparison with a slight contribution from estrone (E1) and estriol (E3).

Copper and zinc, but not other priority toxic metals, pose risks to native aquatic species in a large urban lake in Eastern China.

Over the past 20 years, global production of copper (Cu) and zinc (Zn) rank in the top three compared to other metals such as Pb, Cd, Cr, Ni, As and Hg. However, due to the potential for exposure and toxicity to humans, more attention of environmental pollution was paid to other metals such as Cd and Hg. Aquatic organisms are sensitive to Cu and Zn.

Fugacity gradients of hydrophobic organics across the air-water interface measured with a novel passive sampler.

Mass transfer of hydrophobic organic contaminants (HOCs) across the air-water interface is an important geochemical process controlling the fate and transport of HOCs at the regional and global scales. However, few studies have characterized concentration or fugacity profiles of HOCs near both sides of the air-water interface, which is the driving force for the inter-compartmental mass transfer of HOCs. Herein, we introduce a novel passive sampling device which is capable of measuring concentration (and therefore fugacity) gradients of HOCs across the air-water interface.

Amendment of water quality standards in China: viewpoint on strategic considerations.

Water quality standards (WQS) are the most important tool for protection of quality of aquatic environments in China and play a decisive role in the management of China's aquatic environments. Due to limited scientific information available previously, WQS were developed largely based on water quality criteria (WQC) or WQS recommended by developed countries, which may not be suitable for current circumstances in China. The Chinese government recently initiated the revision of Environmental Quality Standards for Surface Water (EQSSW) (GB3838-2002) to meet the challenge of environmental protection.

Cu/Cu2O/CuO loaded on the carbon layer derived from novel precursors with amazing catalytic performance.

A simple, novel method for synthesis of Cu/Cu2O/CuO on surfaces of carbon (Cu/Cu2O/CuO@C) as a non-noble-metal catalyst for reduction of organic compounds is presented. Compared with noble metals, Cu/Cu2O/CuO@C particles are more efficient and less expensive. Characterization of the Cu/Cu2O/CuO@C composites by high-resolution transmission electron microscope (HRTEM), x-ray diffraction (XRD), infrared spectroscopy and Raman analysis, revealed that it was composed of graphitized carbon with numerous nanoparticles (100nm in diameter) of Cu/CuO/Cu2O that were uniformly distributed on internal and external surfaces of the carbon support.

Magnetic Nanoparticles Interaction with Humic Acid: In the Presence of Surfactants.

Adsorbed humic acid (HA) on surfaces of nanoparticles (NPs) will affect their transport, transfer, and fate in the aquatic environment, especially in the presence of surfactants, and thereby potentially alter exposures and bioavailable fractions of NPs and surfactants. This study investigated adsorption of HA on Fe3O4 NPs in the presence or absence of surfactant. Surfactant established a bridge connecting HA and Fe3O4 NPs, and significantly changed adsorption behavior of HA on NPs.

Predicting toxic potencies of metal oxide nanoparticles by means of nano-QSARs.

Background: The enormous physicochemical and structural diversity of metal oxide nanoparticles (MeONPs) poses significant challenges to the testing of their biological uptake, biodistribution, and effects that can be used to develop understanding of key nano-bio modes of action. This has generated considerable uncertainties in the assessment of their human health and environmental risks and has raised concerns about the adequacy of their regulation. In order to surpass the extremely resource intensive case-by-case testing, intelligent strategies combining testing methods and non-testing predictive modeling should be developed.

Characterization of plant-derived carbon and phosphorus in lakes by sequential fractionation and NMR spectroscopy.

Although debris from aquatic macrophytes is one of the most important endogenous sources of organic matter (OM) and nutrients in lakes, its biogeochemical cycling and contribution to internal load of nutrients in eutrophic lakes are still poorly understood. In this study, sequential fractionation by H2O, 0.1M NaOH and 1.

Characteristics and Kinetic Analysis of AQS Transformation and Microbial Goethite Reduction:Insight into "Redox mediator-Microbe-Iron oxide" Interaction Process.

The characteristics and kinetics of redox transformation of a redox mediator, anthraquinone-2-sulfonate (AQS), during microbial goethite reduction by Shewanella decolorationis S12, a dissimilatory iron reduction bacterium (DIRB), were investigated to provide insights into "redox mediator-iron oxide" interaction in the presence of DIRB. Two pre-incubation reaction systems of the "strain S12- goethite" and the "strain S12-AQS" were used to investigate the dynamics of goethite reduction and AQS redox transformation. Results show that the concentrations of goethite and redox mediator, and the inoculation cell density all affect the characteristics of microbial goethite reduction, kinetic transformation between oxidized and reduced species of the redox mediator.

Characterization of organic matter of plants from lakes by thermal analysis in a N2 atmosphere.

Organic matter (OM) has been characterized using thermal analysis in O2 atmospheres, but it is not clear if OM can be characterized using slow thermal degradation in N2 atmospheres (STDN). This article presents a new method to estimate the behavior of OM in anaerobic environment. Seventeen different plants from Tai Lake (Ch: Taihu), China were heated to 600 °C at a rate of 10 °C min(-1) in a N2 atmosphere and characterized by use of differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA).

Tracking human footprints in Antarctica through passive sampling of polycyclic aromatic hydrocarbons in inland lakes.

Freely dissolved polycyclic aromatic hydrocarbons (PAHs) were monitored in seven inland lakes of Antarctica by a polyethylene (PE)-based passive sampling technique, with the objective of tracking human footprints. The measured concentrations of PAHs were in the range of 14-360 ng L(-1) with the highest values concentrated around the Russian Progress II Station, indicating the significance of human activities to the loading of PAHs in Antarctica. The concentrations of PAHs in the inland lakes were in the upper part of the PAHs levels in aquatic environments from remote and background regions across the globe.

Directly Predicting Water Quality Criteria from Physicochemical Properties of Transition Metals.

Transition metals are a group of elements widespread in aquatic environments that can be hazardous when concentrations exceeding threshold values. Due to insufficient data, criteria maximum concentrations (CMCs) of only seven transition metals for protecting aquatic life have been recommended by the USEPA. Hence, it is deemed necessary to develop empirical models for predicting the threshold values of water quality criteria (WQC) for other transition metals for which insufficient information on toxic potency is available.

Thermodynamic Study on the Protonation Reactions of Glyphosate in Aqueous Solution: Potentiometry, Calorimetry and NMR spectroscopy.

Glyphosate [N-(phosphonomethyl)glycine] has been described as the ideal herbicide because of its unique properties. There is some conflicting information concerning the structures and conformations involved in the protonation process of glyphosate. Protonation may influence the chemical and physical properties of glyphosate, modifying its structure and the chemical processes in which it is involved.