利用工业废弃物脱硫石膏(flue gas desulfurization gypsum,FGDG)作为吸附剂,在静态吸附条件下,从温度、p H值等方面考察了FGDG对多种重金属离子的吸附能力以及多种重金属离子共存在下的吸附过程。基于水合半径和带电量对于吸附过程的影...利用工业废弃物脱硫石膏(flue gas desulfurization gypsum,FGDG)作为吸附剂,在静态吸附条件下,从温度、p H值等方面考察了FGDG对多种重金属离子的吸附能力以及多种重金属离子共存在下的吸附过程。基于水合半径和带电量对于吸附过程的影响,初步提出一个传质模型。在多元重金属离子存在的体系中,水合半径和电荷大小对竞争吸附结果有显着影响,五种重金属离子竞争能力顺序表现为:Pb^(2+)>Cr3+>Cd^(2+)>Mn^(2+)>Cu^(2+)。Langmuir模型推测吸附模型中化学吸附主要属于单层吸附过程,Freundlich模型能够描述FGDG与重金属离子物理吸附属于多层吸附过。XRD定性分析后,FGDG与重金属离子可形成Cu-S,Cd-S,Cr-S,Mn-S,Pb-S。展开更多
The adsorption method has the advantages of low cost,high efficiency,and environmental friendliness in treating fluorinated wastewater,and the adsorbent material is the key.This study combines the inherent anion-excha...The adsorption method has the advantages of low cost,high efficiency,and environmental friendliness in treating fluorinated wastewater,and the adsorbent material is the key.This study combines the inherent anion-exchange adsorption properties of layered double hydroxides(LDHs).Self-supported porous adsorbent materials loaded with AFm and AFt were prepared from a composite cementitious system consisting of calcium aluminate cement(CAC)and flue gas desulfurization gypsum(FGDG)by chemical foaming technique.The mineral composition of the adsorbent material was characterized by X-ray diffraction(XRD)and Scanning electron microscopy(SEM).Through the static adsorption experiment,the adsorption effect of the mineral composition of the adsorbent on fluoride ions was deeply analyzed,and the adsorption mechanism was revealed.XRD and SEM showed that the main hydration phases of the composite cementitious system consisting of CAC and FGDG are AFm,AFt,AH_(3),and CaSO_(4)·2H_(2)O.FGDG accelerates the hydration process of CAC and inhibits the transformation of AFt to AFm.The AFt content increased,and the AFm content decreased or even disappeared as the amount of FGDG increased.Static adsorption experiment results showed that AFm and AFt in adsorbent materials could significantly enhance the adsorption of fluoride ions.The adsorption of F^(−)in aqueous solution by PAG tends more towards monolayer adsorption with a theoretical maximum capacity of 108.70 mg/g and is similar to the measured value of 112.77 mg/g.展开更多
Controlling dissolved phosphorus(DP)loss from high P soil to avoid water eutrophication is a worldwide high priority.A greenhouse study was conducted in which flue gas desulfurization gypsum(FGDG)was applied by using ...Controlling dissolved phosphorus(DP)loss from high P soil to avoid water eutrophication is a worldwide high priority.A greenhouse study was conducted in which flue gas desulfurization gypsum(FGDG)was applied by using different application methods and rates to two agricultural soils.Phosphorus fertilizer was incorporated into the soils at 2.95 g kg^(-1)to simulate soil with high P levels.The FGDG was then applied at amounts of 0,1.5,and 15 g kg^(-1)soil on either the soil surface or mixed throughout the soil samples to simulate no-tillage and tillage,respectively.Ryegrass was planted after treatment application.The study showed that FGDG reduced runoff DP loss by 33%and leachate DP loss 38%in silt loam soil,and runoff DP loss 46%and leachate DP loss 14%in clay loam soil,at the treatment of 15 g kg^(-1)FGDG.Mixing applied method(tillage)provided strong interaction with higher FGDG.To overall effect,the mixing-applied method performed better in controlling DP loss from silt loam soil,while surface-applied(no tillage)showed its advantage in controlling DP loss from clay loam soil.In practice it is necessary to optimize FGDG concentrations,application methods,and DP sources(runoff or leachate)to get maximized benefits of FGDG application.The FGDG application had no negative effects on the soil and ryegrass.展开更多
文摘利用工业废弃物脱硫石膏(flue gas desulfurization gypsum,FGDG)作为吸附剂,在静态吸附条件下,从温度、p H值等方面考察了FGDG对多种重金属离子的吸附能力以及多种重金属离子共存在下的吸附过程。基于水合半径和带电量对于吸附过程的影响,初步提出一个传质模型。在多元重金属离子存在的体系中,水合半径和电荷大小对竞争吸附结果有显着影响,五种重金属离子竞争能力顺序表现为:Pb^(2+)>Cr3+>Cd^(2+)>Mn^(2+)>Cu^(2+)。Langmuir模型推测吸附模型中化学吸附主要属于单层吸附过程,Freundlich模型能够描述FGDG与重金属离子物理吸附属于多层吸附过。XRD定性分析后,FGDG与重金属离子可形成Cu-S,Cd-S,Cr-S,Mn-S,Pb-S。
基金supported by the National Natural Science Foundation of China(No.52279138)supported by Scientific Research Project of Shanxi Province(2018SF-367).
文摘The adsorption method has the advantages of low cost,high efficiency,and environmental friendliness in treating fluorinated wastewater,and the adsorbent material is the key.This study combines the inherent anion-exchange adsorption properties of layered double hydroxides(LDHs).Self-supported porous adsorbent materials loaded with AFm and AFt were prepared from a composite cementitious system consisting of calcium aluminate cement(CAC)and flue gas desulfurization gypsum(FGDG)by chemical foaming technique.The mineral composition of the adsorbent material was characterized by X-ray diffraction(XRD)and Scanning electron microscopy(SEM).Through the static adsorption experiment,the adsorption effect of the mineral composition of the adsorbent on fluoride ions was deeply analyzed,and the adsorption mechanism was revealed.XRD and SEM showed that the main hydration phases of the composite cementitious system consisting of CAC and FGDG are AFm,AFt,AH_(3),and CaSO_(4)·2H_(2)O.FGDG accelerates the hydration process of CAC and inhibits the transformation of AFt to AFm.The AFt content increased,and the AFm content decreased or even disappeared as the amount of FGDG increased.Static adsorption experiment results showed that AFm and AFt in adsorbent materials could significantly enhance the adsorption of fluoride ions.The adsorption of F^(−)in aqueous solution by PAG tends more towards monolayer adsorption with a theoretical maximum capacity of 108.70 mg/g and is similar to the measured value of 112.77 mg/g.
基金supported by the China Scholarship Council(201306140128)the Young Scientist Fund of the National Natural Science Foundation of China(31901207)by state and federal funds appropriated to The Ohio State University and The Ohio Agricultural Research and Development Center,Wooster,OH,USA.The funders had no role in study design,data collection and analysis,decision to publish,or preparation of the manuscript.
文摘Controlling dissolved phosphorus(DP)loss from high P soil to avoid water eutrophication is a worldwide high priority.A greenhouse study was conducted in which flue gas desulfurization gypsum(FGDG)was applied by using different application methods and rates to two agricultural soils.Phosphorus fertilizer was incorporated into the soils at 2.95 g kg^(-1)to simulate soil with high P levels.The FGDG was then applied at amounts of 0,1.5,and 15 g kg^(-1)soil on either the soil surface or mixed throughout the soil samples to simulate no-tillage and tillage,respectively.Ryegrass was planted after treatment application.The study showed that FGDG reduced runoff DP loss by 33%and leachate DP loss 38%in silt loam soil,and runoff DP loss 46%and leachate DP loss 14%in clay loam soil,at the treatment of 15 g kg^(-1)FGDG.Mixing applied method(tillage)provided strong interaction with higher FGDG.To overall effect,the mixing-applied method performed better in controlling DP loss from silt loam soil,while surface-applied(no tillage)showed its advantage in controlling DP loss from clay loam soil.In practice it is necessary to optimize FGDG concentrations,application methods,and DP sources(runoff or leachate)to get maximized benefits of FGDG application.The FGDG application had no negative effects on the soil and ryegrass.
