Thallium (TI) is a kind of emerging contaminant with strong toxicity. In this study, a low-cost, renewable, biologically low-toxic and environmentally friendly fly ash/chitosan (FACS) composite adsorption material was synthesized by combining the characteristics of chitosan and fly ash to remove thallium from wastewater. SEM, FTIR and XRD analyses showed that the adsorbent mainly contained silicate compounds, and the surface of the particles contained a large number of micro porous structures. The adsorption process was rapid, reaching the adsorption equilibrium after 60min. When the pH value was 8, FACS had the best adsorption effect on TI, which was not conducive to the adsorption of TI in either strong acid or strong base environment. The co-existence of Fe3+ and Mn2+ could facilitate the adsorption of TI by FACS. The adsorption isotherm data were better fitted for the Freundlich model, while the Second-order kinetic model was more suitable for describing the kinetic data. Since the main chemical bond composition and chemical groups of FACS would not change after the adsorption of TI, the removal rate of TI was still high when it was reused after desorption. Because of its simple operation, low cost and reusability, FACS is considered to have certain potential in the removal of TI from wastewater.

To reveal the regularity of arsenic adsorption of sediment, this study explores the law of arsenic adsorption by sediment when Fe3+ and Mn2+ coexist. The experimental results fit the first-order kinetic model and the second-order kinetic model. The surface physicochemical properties of sediment particles were analysed by scanning electron microscopy (SEM), nitrogen adsorption-desorption isotherm and fractal dimension. Characterization of surface area and pore distribution were measured by the BET equation and BJH equation. The results illustrate that the adsorption of arsenic by sediment shows the phenomenon of rapid adsorption in the early stage, slow adsorption in the middle stage and finally adsorption equilibrium. In the presence of coexisting ions, the BET specific surface area was as high as 20.14m2/g, the pore volume as 0.047826cm3/g, the surface pore volume as 43.25cm3, and the surface fractal dimension Ds as the largest.

A kinetics model was established to investigate the effects of condensation of water vapour on the growth of coal-fired particles. The effects of operating parameters on particle growth were numerically studied, including growth time, supersaturation, flue gas temperature, and particle number concentration. The results showed that almost all the particles could grow rapidly more than 2.7 microns in tens of milliseconds. When initial supersaturation is constant, the higher the temperature of flue gas, the larger the amount of condensable vapour and the final diameter of particles. Moreover, when the gas temperature is constant, the higher the degree of saturation, the larger the driving force for vapour condensation and the particle size distribution becomes narrower. Additionally, with the increase of particle number concentration, the competition between particles for water vapours become more intense, and the final diameter for particles are smaller.

The contradiction between supply and demand of resource environment has become increasingly severe because of population expansion and the rapid development of industrial economy. Spatial quantitative evaluation of coupling strength and mutual promotion between industrialization and resource environmental bearing capacity based on panel data can facilitate industrialization and promote sustainable and healthy development of regional economy objectively, scientifically, and rationally. This study proposed a three-level comprehensive evaluation matrix for clustering and comparative analysis of 31 provinces in China to analyse the characteristics of spatial heterogeneity in the coordinated development of industrialization and resource environmental bearing capacity. First, a comprehensive evaluation index system for resource environmental bearing capacity was established based on the differences in resource environmental bearing capacities in various regions of China. Combined with the coordination degree for the evaluation model, the coordination between the resource environmental bearing capacity and the industrialization of the 31 provinces in 2018 was evaluated and compared based on their comprehensive evaluation index. Finally, a cluster comparison analysis was performed in the 31 provinces using the three-level comprehensive evaluation matrix of coupling development of regional economy and resource environmental bearing capacity. Moreover, the accuracy of the coordination degree model was verified according to the clustering results. Results show that the regions with good ordination between industrialization and resource environmental bearing capacity include East and North China. Meanwhile, the provinces with poor coordination mainly include Southwest and Northwest China. The resource environment still restricts the coordination between resource environmental bearing capacity and industrialization development. This study provides a reference for developing differentiated resource environment management measures and countermeasures in various regions in China.

Due to mining, industrial wastewater discharge and agricultural fertilization and other human activities, heavy metal cadmium pollution in water bodies has become increasingly prominent. In this study, the sulfidated nanoscale zero-valent iron was prepared by the method of liquid-phase reduction. The removal behaviour of Cd(II) ion in aqueous solution and the effect of pH in solution on its removal rate were investigated. The synthesized materials before and after the adsorption reaction were characterized by scanning electron microscopy, X-ray diffraction and Zeta potential tester. The removal mechanism of Cd(II) ion in solution was explored in details. The results showed that the S-nZVI particles present a polymeric sheet. They contained Fe0, Fe3O4 and FeS. The removal rate of Cd(II) ion by the S-nZVI particles is higher than the nZVI particles. The reaction mechanism for S-nZVI particles to remove Cd(II) ion is that Cd(II) ion replaces Fe in FeS and then combines with S to form stable CdS compound. S has a significant effect on the oxidation process of iron.

The adsorption of malachite green in aqueous solution onto rice wine lees was carried out in detail. The effects of different rice wine lees dosage, solution pH and initial concentration on the adsorption of malachite green by rice wine lees were studied. The experimental results showed that the removal rate of malachite green increases with the increasing dosage of rice wine lees. When the dosage of rice wine lees is 5 g/L, the removal rate within 30 min is 96.22%. At the same time, the removal rate increases as the pH of the solution increases, and the removal rate is higher in an alkaline environment. The kinetic study was performed by the pseudo-first-order and the pseudo-second-order reactions. According to the experimental data, the pseudo-second-order kinetic model better described the adsorption of dye onto rice wine lees, it implies that the predominant process is chemisorption. Besides, the adsorption isotherms were studied by Langmuir model, Freundlich and Temkin isotherm models. The results indicated that the adsorption followed the Langmuir model and the maximum adsorption capacity was 21.505 mg/g. The dye malachite green adsorption onto rice wine lees was monolayer adsorption.

Evaporation (Ea) is a key component of the hydrological cycle. Under the impact of global change, Ea has changed significantly, both globally and regionally. A number of methods have been developed to estimate Ea and its trends. Among them, methods based on the complementary principle of Bouchet estimate Ea using only routine meteorological data as inputs and greatly simplify the Ea estimation. In this study, a new nonlinear formulation of this principle was tested for estimating Ea trends in 6 major river basins of China. The results indicate that the estimated annual Ea trends were in good agreement with that obtained from the water balance approach with the relative errors ranging from -12.0 to 11.2%. In addition, in two humid basins of this study, decreasing Ea trends were estimated from decreasing potential evaporation, although the nonlinear formulation is based on the complementary principle between Ea and potential evaporation. One advantage of the method is that only routine meteorological data are required as inputs and that it can be used to estimate Ea trends, wherever such data are available.

The land is the material basis for human survival, and the contradiction between people and land has become increasingly prominent. The land ecological problem has gradually become a hot spot of concern. It is imperative to make a scientific evaluation of the land ecological quality and propose reasonable and feasible improvement measures and recommendations. At present, domestic research on environmental cost and environmental cost degradation mostly focuses on theoretical discussion, and there are few applications and practical research on enterprise environmental cost management. Based on the principle of protecting the ecological environment, this paper creates an ecological service assessment model to assess the real economic cost of land use development projects. From small community projects to large-scale national projects, because environmental costs are difficult to estimate, this paper uses the recovery cost method and the preventive expenditure method to quantify environmental costs. The cost of environmental degradation mainly comes from water pollution and air pollution. This paper uses the pollution function method to quantify the cost of environmental degradation. The InVEST model is used to evaluate the value of ecosystem services, and the BP neural network method is used to optimize the ecosystem service model, and the sensitivity analysis of the data is used to feedback the impact of the project on ecosystem services. The ecosystem service model based on neural network optimization makes the accuracy of data measurement results reaching 99.7%, which makes the model having a good generalization. Taking a paper mill as an example, this paper evaluates environmental costs by resource consumption cost, environmental degradation value and environmental governance cost, and estimates environmental degradation costs by major environmental governance costs. Finally, the environmental cost and environmental degradation cost are integrated, and the ecosystem service model is established. The neural network model was established in the Matlab environment based on the InVEST model, and the model simulation results of the ecosystem service system were obtained. Compared with the InVEST results, the results of this paper have better authenticity and market utilization value. Although a paper mill was used as an example, the system was evaluated and the evaluation results were analysed. Compared with the actual situation, there is a certain reliability. However, due to the limited data, the number of verifications is insufficient for the system. It is hoped that more data can be verified later to ensure its reliability.

Raw kaolinite clay collected from Ire-Ekiti, Ekiti State, Nigeria, was used to adsorb some heavy metals (Pb, Cr, Ni and Cu) from their aqueous solution through batch experiments. Adsorption studies were performed at the different temperatures, concentration and time to determine the kinetics, isotherm and thermodynamic properties of the adsorption processes. The adsorption thermodynamic properties showed that sorption of Cu, Cr and Ni on the raw clay was exothermic, while adsorption of Pb was endothermic. The negative values of ?G for Pb adsorption revealed the feasibility and spontaneity of the adsorption process while the positive ?G values for Cu, Cr and Ni sorption showed non-spontaneity of the adsorption process. Langmuir, Freundlich and Elovich isotherms were applied to explicate the nature of adsorption process, while Pseudo-first-order (PFO), Pseudo-second-order and Elovich kinetics were applied to literarily determine the adsorbate-adsorbent interaction. Pseudo-second-order kinetics was the best fitting kinetics for adsorption of the metals on the raw clay.

Microtopographies affect large portions of the Chinese Loess Plateau after years of water erosion. Vegetation restoration has proven to be an effective way to conserve water and soil, however, studies of the influence of microtopography on naturally recovered vegetation on the Chinese Loess Plateau have long been absent. The objective of this study was to determine the influence of microtopography on the vegetation structure and plant diversity of naturally restored vegetation and compare the soil physicochemical properties of different microtopographies with those of undisturbed slopes on the Loess Plateau. We identified five types of microtopographies that are mainly shaped by runoff in the study area and examined vegetation structures, plant diversity, soil nutrients, and soil water storage compared with undisturbed slopes. The results show that vegetation communities on loess slopes are still in an early successional stage after 14 years of natural recovery. Vegetation diversity was significantly different among microtopographies. Four types of microtopography have better soil conditions for vegetation restoration; scarps are the exception. Our results suggest that microtopographies can create some better condition plots for precision designed artificial restoration of vegetation, which is necessary to accelerate the succession process on the Loess Plateau.