Contribution of plastic solid components to volatile organic compounds formation during plastics combustion.

The combustion of plastic waste releases volatile organic compounds (VOCs) that are harmful to human health. However, information on the micro-mechanisms of VOC formation remains lacking. Here, the study hypothesized and verified the relationship between VOC formation and solid component degradation during plastics combustion.

Seasonal dynamics and driving mechanisms of microbial biogenic elements cycling function, assembly process, and co-occurrence network in plateau lake sediments.

Microbial community diversity significantly varies with seasonality. However, little is known about seasonal variation of microbial community functions in lake sediments and their associated environmental influences. In this study, metagenomic sequencing of sediments collected from winter, summer, and autumn from Caohai Lake, Guizhou Plateau, were used to evaluate the composition and function of sediment microbial communities, the potential interactions of functional genes, key genes associated with seasons, and community assembly mechanisms.

Loss of submerged macrophytes in shallow lakes alters bacterial and archaeal community structures, and reduces their co-occurrence networks connectivity and complexity.

Introduction: Bacteria and archaea are important components in shallow lake ecosystems and are crucial for biogeochemical cycling. While the submerged macrophyte loss is widespread in shallow lakes, the effect on the bacteria and archaea in the sediment and water is not yet widely understood.

Methods: In this study, 16S rRNA gene sequencing was used to explore the bacteria and archaea in samples taken from the sediment and water in the submerged macrophyte abundant (MA) and submerged macrophyte loss (ML) areas of Caohai Lake, Guizhou, China.

Insight into interactions between microplastics and fulvic acid: Mechanisms affected by microplastics type.

Microplastics (MPs) can interact with dissolved organic matter (DOM), a common component found in the environment. However, the effect of MPs type on its interaction with DOM has not been systematically studied. Therefore, the binding properties of different MPs with fulvic acid (FA) were explored in this study.

Microplastic distribution and migration in soil, water and sediments in Caohai Lake under the different hydrological periods, Southwest China.

An increasing number of researchers have focused on microplastics (MPs) pollution in inland freshwater lakes due to its ecotoxicity, while little is known about the effects of hydrological periods on MPs distribution. Therefore, this study aims to investigate MPs distribution, morphological characteristics and physicochemical indices in various environments in dry and wet periods in Caohai Lake. The results exhibited that cultivated soil, water, and sediment in Caohai Lake have been polluted by MPs in dry and wet periods.

A systematic review of microplastics in the environment: Sampling, separation, characterization and coexistence mechanisms with pollutants.

Microplastics (<5 mm) (MPs) are widely distributed throughout the world, and their accumulation and migration in the environment have caused health and safety concerns. Currently, most of the reviewed literatures mainly focus on the distribution in various environmental media, adsorption mechanisms with different pollutants, and characterization of MPs. Therefore, the present review mainly highlights the characterization techniques of MPs and the underlying mechanisms of their combination with conventional coexisting substances (heavy metals, organic pollutants, and nutrients).

Impacts of Rice-Rape Rotation on Major Soil Quality Indicators of Soil in the Karst Region.

Arable land resources in karst regions are relatively scarce. The original crop rotation pattern can no longer meet the requirements of productivity development, while different crop rotation patterns have different impacts on the physicochemical properties of the soil. Through field experiments and laboratory analysis, the physicochemical properties and pollution characteristics of the soil during different crop growing stages in rice-rape rotation were investigated systematically.

Photocatalytic degradation of tetracycline hydrochloride by a FeO/g-CN/rGO magnetic nanocomposite mechanism: modeling and optimization.

The photocatalytic degradation of antibiotics requires a good separation efficiency of photogenerated electron-hole pairs and a wide visible light absorption range. Current studies have discussed the successful preparation of ferroferric oxide/graphite carbon nitride/reduced graphene oxide (FeO/g-CN/rGO). The phase structure and morphology of the FeO/g-CN/rGO composites were characterized by XRD, HR-TEM, SEM, and EDS.

Graphene-based photocatalytic nanocomposites used to treat pharmaceutical and personal care product wastewater: A review.

Photocatalytic technology has been widely studied by researchers in the field of environmental purification. This technology can not only completely convert organic pollutants into small molecules of CO and HO through redox reactions but also remove metal ions and other inorganic substances from water. This article reviews the research progress of graphene-based photocatalytic nanocomposites in the treatment of wastewater.

Distribution characteristics and risk of heavy metals and microbial community composition around the Wanshan mercury mine in Southwest China.

The Wanshan mercury (Hg) mine in Guizhou Province is one of the main Hg-producing mines in China, resulting in serious Hg pollution in soil and wastewater. Therefore, the present study is mainly aimed to investigate the current degree of heavy metal pollution and compared the microbial diversity in the Wanshan Hg mine and its surrounding environment. The results showed the distribution of the pollution load index values was low in the west and high in the east.

Binary Dye Removal from Simulated Wastewater Using Reduced Graphene Oxide Loaded with Fe-Cu Bimetallic Nanocomposites Combined with an Artificial Neural Network.

Reduced graphene oxide loaded with an iron-copper nanocomposite was prepared in this study, using graphene oxide as a carrier and ferrous sulfate, copper chloride and sodium borohydride as raw materials. The obtained material was prepared for eliminating hazardous dye carmine and the binary dye mixture of carmine and Congo red. The process of carmine dye removal by the nanocomposite was modeled and optimized through response surface methodology and artificial intelligence (artificial neural network-particle swarm optimization and artificial neural network-genetic algorithm) based on single-factor experiments.

Spatial heterogeneity of pH and heavy metal Cd in the soils of tea gardens in the plateau mountain regions, PR China.

To explore the spatial heterogeneity of pH and cadmium (Cd) content in the soils of the tea gardens in the plateau mountain regions as well as its driving factors, the pH values, Cd content and other physical and chemical indicators from 423 soil samples were examined. A coefficient of variation method and a semivariance function model was adopted to explore the soils' spatial heterogeneity, and a random forest approach was applied to evaluate the factors influencing environmental Cd under different pH values. The results show that the pH values of the soils of the tea gardens in the plateau mountain regions were within the appropriate range for the growth of tea plants, and soil samples with pH values falling between 4.

Health risk assessment of heavy metals in soils and screening of accumulating plants around the Wanshan mercury mine in Northeast Guizhou Province, China.

The Wanshan mercury mine, which is an abandoned mine located in northeastern Guizhou Province in Southwest China, has introduced serious Hg pollution to the local ecosystem resulting from previous mining and smelting activities. However, it is not clear to date whether soil pollution has actually improved after treatment by related departments. Therefore, the present study investigates the vegetation community and heavy metal contents of the soil and plants in the Wanshan mercury mining area.

Speciation Variation and Bio-Activation of Soil Heavy Metals (Cd and Cr) in Rice-Rape Rotation Lands in Karst Regions.

Heavy metals in soil are in a high background state in Karst areas, and agricultural activities will affect the bioactivity of heavy metals. The heavy metal (Cd and Cr) bioactivity and their activation effects in rice-rape rotation lands in Karst areas were studied based on field experiments and laboratory analysis, and the influencing factors of heavy metal activity were analyzed based on the physical and chemical properties of soil. The results suggest that the residual fraction was the largest and the exchangeable fraction was the smallest for both Cr and Cd in rice-rape rotation lands in Karst areas.

Relationships between soil properties and the accumulation of heavy metals in different Brassica campestris L. growth stages in a Karst mountainous area.

The speciation and activity of heavy metals in farmland were changed with the different soil properties and flooded environment, especially in the complex and rainy environment in soil of Guizhou Province. The objective of this study was to explore the concentrations of a variety of heavy metal activity and the speciation of those heavy metals in rhizosphere soil at different growth stages of Brassica campestris L. in a Karst mountainous area.

Full use of factors promoting catalytic performance of chitosan supported manganese porphyrin.

In order to make full use of the impact of internal and external factors on the performance of title catalyst for ethyl benzene oxidation, the key internal influencing factors on the catalytic performance were modulated by coordinating and grafting manganese porphyrin to mesoporous and macroporous chitosan, and the important external factors (i.e. oxidation reaction conditions) were optimized using Response Surface Methodology.

Soil Organic Carbon Dynamics and Driving Factors in Typical Cultivated Land on the Karst Plateau.

Due to the impacts of unwise industrial agriculture, extreme precipitation events are increasing in frequency and are accelerating the process of global warming in the karst area. The dynamic change in soil organic carbon (SOC) and its driving factors in cultivated land in the last 35 years were studied by using data from the second national soil survey of China and measurements made in 2015. The results indicated that the SOC per unit area of cultivated land increased by 32.

The Spatial Distribution Characteristics of Soil Organic Carbon and Its Effects on Topsoil under Different Karst Landforms.

Karst landforms are widely distributed in Guizhou Province, and the karst terrain is complex. To investigate the spatial distribution characteristics of soil organic carbon (SOC) in topsoil in different karst landforms, a total of 920 samples were taken from different karst landforms. The study areas, Puding, Xingyi, Guanling, Libo and Yinjiang in Guizhou Province, represent the karst plateau (KP), karst peak-cluster depression (KPCD), karst canyon (KC), karst virgin forest (KVF) and karst trough valley (KTV) landforms, respectively.

Discrepancies in Karst Soil Organic Carbon in Southwest China for Different Land Use Patterns: A Case Study of Guizhou Province.

The assessment of soil organic carbon (SOC) in mountainous karst areas is very challenging, due to the high spatial heterogeneity in SOC content and soil type. To study and assess the SOC storage in mountainous karst areas, a total of 22,786 soil samples were collected from 2,854 soil profiles in Guizhou Province in Southwest China. The SOC content in the soil samples was determined by the oxidation of potassium dichromate (KCrO), followed by titration with iron (II) sulfate (FeSO).

Effects of Small Gaps on the Relationship Among Soil Properties, Topography, and Plant Species in Subtropical Rhododendron Secondary Forest, Southwest China.

: The secondary forests have become the major forest type worldwide, and forest gap was also a common small disturbance in secondary forests. We aimed to analyze the effects of small gap disturbance on the plant species richness of subtropical secondary forest with natural regeneration barriers and examine the relationship between soil topography and plant species in a subtropical Rhododendron secondary forest of the Baili Rhododendron National Nature Reserve. : The major plant species and soil topography gradient factors of the small gaps and closed canopy (control group) were analyzed using two-way ANOVA, multivariate permutational analysis of variance, nonmetric multi-dimensional scaling, random forest, canonical correspondence analysis, redundancy analysis, and a generalized linear model.

Highly Active Catalysis of Cobalt Tetrakis(pentafluorophenyl)porphyrin Promoted by Chitosan for Cyclohexane Oxidation in Response-Surface-Methodology-Optimized Reaction Conditions.

We aimed at elevating catalytic performances of cobalt tetrakis(pentafluorophenyl)porphyrin (Co TPFPP) through axial coordination, nanocavities, and covalently grafting action. The Co TPFPP was immobilized onto nanoporous and nonporous chitosan, forming Co TPFPP/np- and nonp-CTS catalysts, respectively. The catalysts were characterized by various spectroscopic techniques.

Carbon Sequestration Anticipation Response to land use change in a mountainous karst basin in China.

The present article reports an assessment of afforestation potential and anticipation of carbon sequestration in the Houzhai River Basin in Guizhou Province in southwestern China. Total of 2755 soil profiles consisting of 22,057 soil samples were collected according to a grid-sampling method at a 150 m scale in the Houzhai River basin, and the SOC contents in soil samples were analyzed using a titration method. General information regarding the geographic characteristics of each sampling grid was recorded in the field.

Spatial Distribution of Stony Desertification and Key Influencing Factors on Different Sampling Scales in Small Karst Watersheds.

Karst areas are typical ecologically fragile areas, and stony desertification has become the most serious ecological and economic problems in these areas worldwide as well as a source of disasters and poverty. A reasonable sampling scale is of great importance for research on soil science in karst areas. In this paper, the spatial distribution of stony desertification characteristics and its influencing factors in karst areas are studied at different sampling scales using a grid sampling method based on geographic information system (GIS) technology and geo-statistics.

Heavy Metal Pollution and Ecological Assessment around the Jinsha Coal-Fired Power Plant (China).

Heavy metal pollution is a serious problem worldwide. In this study, 41 soil samples and 32 cabbage samples were collected from the area surrounding the Jinsha coal-fired power plant (JCFP Plant) in Guizhou Province, southwest China. Pb, Cd, Hg, As, Cu and Cr concentrations in soil samples and cabbage samples were analysed to study the pollution sources and risks of heavy metals around the power plant.