The potential of microbial mediated iron plaque reduction, and associated arsenic （As） mobility were examined by iron reducing bacteria enriched from As contaminated paddy soil. To our knowledge, this is the first t...The potential of microbial mediated iron plaque reduction, and associated arsenic （As） mobility were examined by iron reducing bacteria enriched from As contaminated paddy soil. To our knowledge, this is the first time to report the impact of microbial iron plaque reduction on As mobility. Iron reduction occurred during the inoculation of iron reducing enrichment culture in the treatments with iron plaque and ferrihydrite as the electron acceptors, respectively. The Fe（II） concentration with the treatment of anthraquinone-2, 6-disulfonic acid （AQDS） and iron reducing bacteria increased much faster than the control. Arsenic released from iron plaque with the iron reduction, and a significant correlation between Fe（II） and total As in culture was observed. However, compared with control, the increasing rate of As was inhibited by iron reducing bacteria especially in the presence of AQDS. In addition, the concentrations of As（III） and As（V） in abiotic treatments were higher than those in the biotic treatments at day 30. These results indicated that both microbial and chemical reductions of iron plaque caused As release from iron plaque to aqueous phase, however, microbial iron reduction induced the formation of more crystalline iron minerals, leading to As sequestration. In addition, the presence of AQDS in solution can accelerate the iron reduction, the As release from iron plaque and subsequently the As retention in the crystalline iron mineral. Thus, our results suggested that it is possible to remediate As contaminated soils by utilizing iron reducing bacteria and AQDS.展开更多
A novel method for the determination of cationic surfactant by laser thermal lens spectrometry was developed. It was based on the reaction between 1-hydroxy-2-(5-nitro-2-Pyri- dylazo)-8-aminonaphthalene-3,6-disulfoni...A novel method for the determination of cationic surfactant by laser thermal lens spectrometry was developed. It was based on the reaction between 1-hydroxy-2-(5-nitro-2-Pyri- dylazo)-8-aminonaphthalene-3,6-disulfonic acid (5-NO2-PAH) and cationic surfactant to form 1:2 ionic association complex in a weakly basic medium (pH 9.44). The determination conditions and the mechanism were discussed. The method has been applied to the analysis of wastewater and moat water samples.展开更多
Separation and determination of metal ions based on the formation of chelate anions with 1-Nitroso-2, 7-dihydrexynaphthalene-3, 6-disulfonic acid (1N2, 7O3, 6S) was studied by rising HPCE of the nine metal ions examin...Separation and determination of metal ions based on the formation of chelate anions with 1-Nitroso-2, 7-dihydrexynaphthalene-3, 6-disulfonic acid (1N2, 7O3, 6S) was studied by rising HPCE of the nine metal ions examined, the ions that can be detected sensitively with 1-Nitroso-2, 7-dihydrexynaphthalene-3, 6-disulfonic acid were Fe2+, Co2+, Cu2+, Ni2+, Zn2+ and Pd2+. The cobalt chelate could exist in two oxidation states of cobalt. When TBA(+) were added in electrophoretic solutions, the drastic changes in elertrophoretic mobilities of chelate were observed, which was due to the ion association between chelates anions and TBA(+). The ion association constants of chelate anions with TBA(+) were determined by using the change in electrophoretic mobilities of chelates, metal ions tested were separated within 10 min using 30cm silica capillary (50 m i. d).展开更多
基金supported by the Knowledge Innovation Program of Chinese Academy of Sciences(No. KZCX1-YW-06-03)
文摘The potential of microbial mediated iron plaque reduction, and associated arsenic （As） mobility were examined by iron reducing bacteria enriched from As contaminated paddy soil. To our knowledge, this is the first time to report the impact of microbial iron plaque reduction on As mobility. Iron reduction occurred during the inoculation of iron reducing enrichment culture in the treatments with iron plaque and ferrihydrite as the electron acceptors, respectively. The Fe（II） concentration with the treatment of anthraquinone-2, 6-disulfonic acid （AQDS） and iron reducing bacteria increased much faster than the control. Arsenic released from iron plaque with the iron reduction, and a significant correlation between Fe（II） and total As in culture was observed. However, compared with control, the increasing rate of As was inhibited by iron reducing bacteria especially in the presence of AQDS. In addition, the concentrations of As（III） and As（V） in abiotic treatments were higher than those in the biotic treatments at day 30. These results indicated that both microbial and chemical reductions of iron plaque caused As release from iron plaque to aqueous phase, however, microbial iron reduction induced the formation of more crystalline iron minerals, leading to As sequestration. In addition, the presence of AQDS in solution can accelerate the iron reduction, the As release from iron plaque and subsequently the As retention in the crystalline iron mineral. Thus, our results suggested that it is possible to remediate As contaminated soils by utilizing iron reducing bacteria and AQDS.
文摘A novel method for the determination of cationic surfactant by laser thermal lens spectrometry was developed. It was based on the reaction between 1-hydroxy-2-(5-nitro-2-Pyri- dylazo)-8-aminonaphthalene-3,6-disulfonic acid (5-NO2-PAH) and cationic surfactant to form 1:2 ionic association complex in a weakly basic medium (pH 9.44). The determination conditions and the mechanism were discussed. The method has been applied to the analysis of wastewater and moat water samples.
文摘Separation and determination of metal ions based on the formation of chelate anions with 1-Nitroso-2, 7-dihydrexynaphthalene-3, 6-disulfonic acid (1N2, 7O3, 6S) was studied by rising HPCE of the nine metal ions examined, the ions that can be detected sensitively with 1-Nitroso-2, 7-dihydrexynaphthalene-3, 6-disulfonic acid were Fe2+, Co2+, Cu2+, Ni2+, Zn2+ and Pd2+. The cobalt chelate could exist in two oxidation states of cobalt. When TBA(+) were added in electrophoretic solutions, the drastic changes in elertrophoretic mobilities of chelate were observed, which was due to the ion association between chelates anions and TBA(+). The ion association constants of chelate anions with TBA(+) were determined by using the change in electrophoretic mobilities of chelates, metal ions tested were separated within 10 min using 30cm silica capillary (50 m i. d).
