To achieve a safe treatment of arsenic-containing acid wastewater,a new process was proposed,including arsenic removal via sulfide precipitation and hydrothermal mineralization stabilization.Under optimal conditions o...To achieve a safe treatment of arsenic-containing acid wastewater,a new process was proposed,including arsenic removal via sulfide precipitation and hydrothermal mineralization stabilization.Under optimal conditions of sulfide precipitation,99.65%of arsenic from wastewater was precipitated in the form of amorphous As2S3.The As leaching concentration of amorphous As2S3 in TCLP(toxicity characteristic leaching procedure)test was up to 212.97 mg/L,therefore,hydrothermal mineralization was adopted to improve the stability of amorphous As2S3.The results showed that the As leaching concentration of mineralized As2S3 was only 4.82 mg/L.Furthermore,the amorphous As2S3 could be transformed into crystallized As2S3(orpiment)in the presence of mineralizer Na2SO4.Simultaneously,the As leaching concentration of crystallized As2S3 was further reduced to 3.86 mg/L.Hydrothermal mineralization was an effective method for the stabilization of As2S3.Therefore,this process has a greater application in the treatment of arsenic-containing wastewater.展开更多
Sulfhydryl magnetic biological bamboo charcoal nanocomposite(BBC@nFe-SH)was prepared by chemical co-precipitation method for the robust capture of As(Ⅲ)from aqueous solutions.The novel BBC@nFe-SH shows favorable magn...Sulfhydryl magnetic biological bamboo charcoal nanocomposite(BBC@nFe-SH)was prepared by chemical co-precipitation method for the robust capture of As(Ⅲ)from aqueous solutions.The novel BBC@nFe-SH shows favorable magnetic field strength(83376 A/m),which enables BBC@nFe-SH to be quickly recovered from aqueous solution.The maximum As(Ⅲ)adsorption capacity is as high as 98.63 mg/g at pH 5.0 and 40°C,reaching reaction equilibrium within 120 min.Various characterizations(e.g.,SEM,FTIR,VSM and XPS)suggest that As(Ⅲ)prefers to coordinate with surface oxygen groups bonded to the surface.BBC@nFe-SH displayed high stability and recyclability throughout the removal process,which could be easily activated by 1 mol/L NaOH after usage.Thus,the novel BBC@nFe-SH has promising applications for As(Ⅲ)treatment.展开更多
Glow discharge electrolysis provides an alternative method for the removal of arsenite from water. Glow discharge electrolysis of aqueous solution containing arsenite is studied under altemating current altemating cur...Glow discharge electrolysis provides an alternative method for the removal of arsenite from water. Glow discharge electrolysis of aqueous solution containing arsenite is studied under altemating current altemating current （50 Hz） discharge. It is found that arsenite [As（III）] get converted to arsenate [As（V）]. The yield is studied with various parameters such as discharge current, duration of discharge and pH （2-10）. The results are interpreted on the basis of interaction of the OH and eaq （produced consequent to the interaction of H2O＋ and e with water at the surface of the solution） with arsenite [As（III）] through the intermediate oxidation state, namely [As（IV）].展开更多
基金Projects(2018YFC1901601,2018YFC1901604,2018YFC1901605) supported by the National Key Research and Development Program of ChinaProject(201806375047) supported by the Visiting Scholar of China Scholarship CouncilProject(51404296) supported by the Young Scientists Fund of the National Natural Science Foundation of China
文摘To achieve a safe treatment of arsenic-containing acid wastewater,a new process was proposed,including arsenic removal via sulfide precipitation and hydrothermal mineralization stabilization.Under optimal conditions of sulfide precipitation,99.65%of arsenic from wastewater was precipitated in the form of amorphous As2S3.The As leaching concentration of amorphous As2S3 in TCLP(toxicity characteristic leaching procedure)test was up to 212.97 mg/L,therefore,hydrothermal mineralization was adopted to improve the stability of amorphous As2S3.The results showed that the As leaching concentration of mineralized As2S3 was only 4.82 mg/L.Furthermore,the amorphous As2S3 could be transformed into crystallized As2S3(orpiment)in the presence of mineralizer Na2SO4.Simultaneously,the As leaching concentration of crystallized As2S3 was further reduced to 3.86 mg/L.Hydrothermal mineralization was an effective method for the stabilization of As2S3.Therefore,this process has a greater application in the treatment of arsenic-containing wastewater.
基金financial support from the Key Research and Development Program of Hunan Province,China (No.2021GK4059)。
文摘Sulfhydryl magnetic biological bamboo charcoal nanocomposite(BBC@nFe-SH)was prepared by chemical co-precipitation method for the robust capture of As(Ⅲ)from aqueous solutions.The novel BBC@nFe-SH shows favorable magnetic field strength(83376 A/m),which enables BBC@nFe-SH to be quickly recovered from aqueous solution.The maximum As(Ⅲ)adsorption capacity is as high as 98.63 mg/g at pH 5.0 and 40°C,reaching reaction equilibrium within 120 min.Various characterizations(e.g.,SEM,FTIR,VSM and XPS)suggest that As(Ⅲ)prefers to coordinate with surface oxygen groups bonded to the surface.BBC@nFe-SH displayed high stability and recyclability throughout the removal process,which could be easily activated by 1 mol/L NaOH after usage.Thus,the novel BBC@nFe-SH has promising applications for As(Ⅲ)treatment.
文摘Glow discharge electrolysis provides an alternative method for the removal of arsenite from water. Glow discharge electrolysis of aqueous solution containing arsenite is studied under altemating current altemating current （50 Hz） discharge. It is found that arsenite [As（III）] get converted to arsenate [As（V）]. The yield is studied with various parameters such as discharge current, duration of discharge and pH （2-10）. The results are interpreted on the basis of interaction of the OH and eaq （produced consequent to the interaction of H2O＋ and e with water at the surface of the solution） with arsenite [As（III）] through the intermediate oxidation state, namely [As（IV）].
