Spatial distribution, source apportionment, and risk assessment of perfluoroalkyl substances in urban soils of a typical densely urbanized and industrialized city, Northeast China.

As an important capital city of intensive urbanization and industrialization in Northeast China, Changchun has experienced extremely rapid development, with diverse sectors such as automobile manufacturing, equipment manufacturing, optoelectronics, and pharmaceutical decoration. However, data on the levels and profiles of perfluoroalkyl substances (PFASs) in urban soils of Changchun is limited. This study investigated 17 PFASs across various functional zones within the main urban area of Changchun.

A systematic investigation of single solute, binary and ternary PFAS transport in water-saturated soil using batch and 1-dimensional column studies: Focus on mixture effects.

This study aimed to investigate the transport and release of per- and polyfluoroalkyl substances (PFAS), as single solutes and binary and ternary mixtures, and associated competitive sorption effects in water-saturated soil. Batch sorption isotherm and desorption, and one-dimensional miscible displacement studies were conducted. For the batch study, the mixtures exhibited extensive sorption isotherm nonlinearity at aqueous concentrations exceeding 20 µg/L.

The interaction of different chlorine-based additives with swine manure during pyrolysis: Effects on biochar properties and heavy metal volatilization.

Poor properties and high concentrations of heavy metals are still major concerns of successful application of animal manure-derived biochar into the environment. This work thus proposed to add chlorine-based additives (Cl-additives, i.e.

Phytoremediation Potential and Physiological Mechanisms Underlying Metallic Extraction of , , and .

Mining activities have led to serious environmental (soil erosion, degradation of vegetation, and groundwater contamination) and human health (musculoskeletal problems, diarrheal conditions, and chronic diseases) issues at desert mining areas in northwest China. Native plant species grown naturally in desert regions show a unique tolerance to arid and semiarid conditions and are potential candidates for soil phytoremediation. Here, an ex situ experiment involving pot planting of seedlings of three native plant species (, , and ) was designed to explore their phytoremediation potential and the underlying physiological mechanism.

A contrasting alteration of sulfamethoxazole bioaccessibility in two different soils amended with polyethylene microplastic: In-situ measurement using diffusive gradients in thin films.

Microplastics and veterinary antibiotics are both emerging environmental contaminants that could be co-occurrence in agricultural soils. However, it's still unclear how the microplastics affect the bioaccessibility of antibiotics in a real soil environment. An in-situ measurement using diffusive gradients in thin-films devices suitable for polar organic compounds (o-DGT) coupled with soil moisture sampling were used to reveal such effects.

Ambient climate determines the directional trend of community stability under warming and grazing.

Changes in ecological processes over time in ambient treatments are often larger than the responses to manipulative treatments in climate change experiments. However, the impacts of human-driven environmental changes on the stability of natural grasslands have been typically assessed by comparing differences between manipulative plots and reference plots. Little is known about whether or how ambient climate regulates the effects of manipulative treatments and their underlying mechanisms.

Quantification of Microplastics in Soils Using Accelerated Solvent Extraction: Comparison with a Visual Sorting Method.

Visual sorting is a method that is widely used in microplastic analysis, but it has limitation in the quantification of small-size microplastics. Accelerated solvent extraction (ASE) which frequently used in the analysis of organic contaminants in soils and sediments was used here for the microplastics quantification. A recovery experiment using different spiked polymeric microplastics separately indicates that ASE was useful in the extraction of low-density and low-melting point polymeric microplastics.

Microplastics in agricultural soils on the coastal plain of Hangzhou Bay, east China: Multiple sources other than plastic mulching film.

Microplastic contamination in agroecosystems raises great concerns. Here, we investigated the impacts of mulching and irrigation on microplastic accumulation in cropped soils. Sixty soil samples covering mulching and no-mulching farmlands, and forty-five irrigation water samples were collected for analysis.

Response of soil enzyme activities and bacterial communities to the accumulation of microplastics in an acid cropped soil.

The ecological stress of microplastics (MPs) contamination in agroecosystems raise worldwide concerns. However very few studies concentrated on the effects of MPs exposure on soil microbial community. The alterations of enzymatic activities and bacterial communities were assayed by spiking 1% and 5% (w/w) of polyethylene (PE) and polyvinyl chloride (PVC) MPs in an acid soil.

Nonlinear effects of increasing nitrogen deposition on rice growth and heavy metal uptake in a red soil ecosystem of southeastern China.

With the population growth, urbanization and industrialization, China has become a hotspot of atmospheric deposition nitrogen (ADN), which is a threat to ecosystem and food safety. However, the impacts of increased ADN on rice growth and grain metal content are little studied. Based on previous long-term ADN studies, greenhouse experiment was conducted with four simulated ADN rates of 0, 30, 60 and 90 kg N ha yr (CK, N, N and N as δN, respectively) to assess rice growth and metal uptake in a red soil ecosystem of southeast China during 2016-2017.

Marine microplastics bound dioxin-like chemicals: Model explanation and risk assessment.

Microplastics have become one of the most pervasive emerging pollutants in the marine environment because of their wide occurrence and high sorption ability for hydrophobic organic contaminants (HOCs). Among the associated HOCs, dioxin-like chemicals (DLCs) can pose severe health risks; however, information on effects of microplastics bound DLCs is lacking. To fill this knowledge gap, this study integrated chemical analysis and in vitro bioassays to elucidate the potential dioxin-like effects of microplastics bound DLCs.

Enhanced adsorption of oxytetracycline to weathered microplastic polystyrene: Kinetics, isotherms and influencing factors.

Microplastic polystyrene foam has been found widely in the environment and is readily transported by wind or water. Beached and virgin foams of size 0.45-1 mm were prepared as sorbents to study oxytetracycline sorption.

Occurrence of microplastics in the water column and sediment in an inland sea affected by intensive anthropogenic activities.

Microplastics may lose buoyancy and occur in deeper waters and ultimately sink to the sediment and this may threaten plankton inhabiting in various water layers and benthic organisms. Here, we conduct the first survey on microplastics in the water column and corresponding sediment in addition to the surface water in the Bohai Sea. A total of 20 stations covering whole Bohai Sea were selected, which included 6 stations specified for water column studying.

Occurrences of organophosphorus esters and phthalates in the microplastics from the coastal beaches in north China.

Chemical pollution in the microplastics has been concerned worldwide as pollutants might potentially transfer from the environment to living organisms via plastics. Here, we investigate organophosphorus esters (OPEs) and phthalic acid esters (PAEs) in the beached microplastics collected from 28 coastal beaches of the Bohai and Yellow Sea in north China. The analyzed microplastics included polyethylene (PE) pellets and fragments, polypropylene (PP) flakes and fragments and polystyrene (PS) foams.

Levels, distributions and sources of veterinary antibiotics in the sediments of the Bohai Sea in China and surrounding estuaries.

Veterinary antibiotics are emerging contaminants of concern. A total of 139 samples comprising 104 marine sediments and 35 estuarine sediments were collected from the Bohai Sea area and analyzed for seventeen antibiotics. The results reveal that the presence and concentration of antibiotics were generally higher in the estuaries than in the sea.

Profile Changes in the Soil Microbial Community When Desert Becomes Oasis.

The conversion of virgin desert into oasis farmland creates two contrasting types of land-cover. During oasis formation with irrigation and fertilizer application, however, the changes in the soil microbial population, which play critical roles in the ecosystem, remain poorly understood. We applied high-throughput pyrosequencing to investigate bacterial and archaeal communities throughout the profile (0-3 m) in an experimental field, where irrigation and fertilization began in 1990 and cropped with winter wheat since then.

[Quantitative prediction of soil salinity content with visible-near infrared hyper-spectra in northeast China].

Studying the spectral property of salinized soil is an important work, for it is the base of monitoring soil salinization by remote sense. To investigate the spectral property of salinized soil and the relationship between the soil salinity and the hyperspectral data, the field soil samples were collected in the region of Northeast China and then reflectance spectra were measured. The partial least squares regression (PLSR) model was established based on the statistical analysis of the soil salinity content and the reflectance of hyperspectra.

[Simulation of rice canopy evapotranspiration and water use efficiency under free-air CO2 enrichment].

By using FACE system, the microclimate in rice canopy and related physiological indices were observed continuously from the elongation to the maturing stage of rice growth, and the effects of FACE on the rice canopy evapotranspiration and water use efficiency were studied and simulated with energy balance analysis. The results showed that using P-M equation to describe the quantitative relationships of rice leaf stomatal conductance with photosynthetically active radiation (PAR) and vapour pressure deficit (VPD) could better simulate rice canopy evapotranspiraton under FACE and ambient conditions. During observation period, the total water use of rice in FACE plot had a 10 mm decrease, compared with that in control plot.

[Adsorption of acid orange II from aqueous solution onto modified peat-resin particles].

The adsorption of acid orange II onto modified peat-resin particles was examined in aqueous solution in a batch system. The Langmuir and Freundlich adsorption models were applied to describe the equilibrium isotherms. The pseudo-first-order, pseudo-second-order kinetic and the intraparticle diffusion models were used to describe the kinetic data.

DFT study on the structure-toxicity relationship of dioxin compounds using PLS analysis.

Density functional theory (DFT) at B3LYP/6-311G** level was employed to optimise the dioxin compounds, i.e., 25 polychlorinated or brominated dibenzo-p-dioxins (PCDDs or PBDDs) and 34 polychlorinated dibenzofurans (PCDFs) involved in this investigation.

QSARs for the toxicity of polychlorinated dibenzofurans through DFT-calculated descriptors of polarizabilities, hyperpolarizabilities and hyper-order electric moments.

DFT-B3LYP method with 6-31G(**) basis set was employed to fully optimize the electronic structures of 135 polychlorinated dibenzofurans and parent compound, namely dibenzofuran. It was demonstrated that polarizability anisotropy and mean polarizability could change sensitively and systematically with chlorine number and substitution pattern. And new quantitative structure-activity relationships (QSARs) focused on the binding affinities of aryl hydrocarbon receptor (AhR), aryl hydrocarbon hydroxylase (AHH) and 7-ethoxyresorufin O-deethylase (EROD) induction potencies of PCDFs were developed.

An approach to the method for determination of surface potential on solid/liquid interface: theory.

The electrochemical properties on solid particle surfaces in an aqueous system have found wide application in many fields. However, for some of them there are no reliable methods of determination. What is particularly worth mentioning is the surface potentials of solid particles.

[Ammonia volatilization loss of nitrogen fertilizer from rice field and wet deposition of atmospheric nitrogen in rice growing season].

Plot and field experiments showed that the NH3 volatilization loss from rice field reached its maximum in 1-3 days after N-fertilization, which was affected by the local climate conditions (e.g., sun illumination, temperature, humidity, wind speed, and rainfall), fertilization time, and ammonium concentration in surface water of the rice field.

The adsorption of basic dyes from aqueous solution on modified peat-resin particle.

Modified peat was prepared by mixing thoroughly raw peat with sulfuric acid, and modified peat-resin particle was obtained, by mixing modified peat with solutions of polyvinylalcohol (PVA) and formaldehyde. In this paper, the adsorption of Basic Magenta and Basic Brilliant Green onto modified peat-resin particle is examined. The adsorption isotherm showed that the adsorption of basic dyes on modified peat-resin particle deviated from the Langmuir and Freundlich equations.