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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.

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.

Sluice and dam ecological scheduling is a complex management system. To realize the goal of ecological scheduling, we must adopt the advanced management mode as a guarantee. Green supply chain management is built on supply chain management and the sustainable development of the modern enterprise management mode. It is commonly used in enterprise management. Through comparative analysis, it is found that the green supply chain management mode and sluice and dam ecological scheduling management system in structure, connotation, management goal, and management theories all have a lot in common. And it is very feasible to apply green supply chain management system in sluice and dam ecological scheduling, and it can be observed obviously superiority in the allocation of water resources, environmental protection, and information sharing and technology promotion. The author tries to construct a sluice and dam ecological scheduling framework of green supply chain management structure and makes a brief description of the management mode. The paper shows that the management model will be beneficial to the efficient allocation of water resources and river ecological environment protection, and will have wide application prospect. [ABSTRACT FROM AUTHOR]