Toward the understanding of the treatment of textile industries’ effluents by clay: adsorption of anionic dye on kaolinite     

Nejib Abidi  Joëlle Duplay  Amane Jada  Raymonde Baltenweck  Emna Errais  Khadija Semhi  Malika Trabelsi-Ayadi 《Arabian Journal of Geosciences》2017,10(16):373

Clays, particularly kaolinite, are promising adsorbents for the treatment of textile effluents, but there is a need of better understanding the mechanisms of adsorption, especially in the case of anionic dyes. Thus, the removal of RR120 anionic dye was investigated using Tunisian raw clay (TBK) composed of kaolinite and illite, and a standard kaolinite (KGa-2), and conducting batch experiments by varying different parameters (contact time, ionic strength, concentration, temperature). We investigated the clays’ surface charges by electrophoretic mobility measures and the dye-clay interactions during adsorption, by the streaming-induced potentials (SIP). The results showed that KGa-2 has higher adsorption capacity for RR120 dye than TBK clay, moreover enhanced by increasing the ionic strength and/or lowering the pH of the aqueous. The SIP results showed an increase of negative charges for both clays, reflecting the adsorption of the anionic dye on the positive charges of the amphoteric surfaces of the clays. The SIP magnitudes indicated a higher adsorption rate for KGa-2 in accordance with the kinetic study. The Sips model that described the best adsorption isotherms indicates lateral interactions of the dye molecules, stronger in the case of KGa-2 than TBK. Also, the dye molecules form a thinner layer on KGa-2 surfaces. In addition, the dye molecule’s structure was not altered, as verified by mass spectrometry. The adsorption process was feasible and spontaneous and favored at ambient temperature. Thus, kaolinite-rich clays are effective in the removal of anionic dyes in aqueous solution and potential good adsorbents in wastewater treatment.  相似文献   

High-resolution terrestrial carbon isotope and planktic foraminiferal records of the Upper Cenomanian to the Lower Campanian in the Northwest Pacific     

Reishi Takashima  Hiroshi Nishi  Toshiro Yamanaka  Keiichi Hayashi  Amane Waseda  Akiko Obuse  Takashige Tomosugi  Naoki Deguchi  Sunao Mochizuki 《Earth and Planetary Science Letters》2010,289(3-4):570-582

Making Upper Cretaceous biostratigraphic correlations between the Northwest Pacific and Tethyan–Atlantic sections have been difficult because of rare frequencies of age-diagnostic macro- and microfossils in the sequences in the Northwest Pacific region. In order to correlate these sections precisely, an integrated planktic foraminiferal and bulk wood carbon-isotope stratigraphy from the upper Cenomanian to the lower Campanian succession (the middle–upper part of the Yezo Group) of Hokkaido, northern Japan is established with an average resolution of 50 k.y. The δ¹³C curves from bulk wood of the Yezo Group and from bulk carbonate of English Chalk show remarkably similar patterns of isotopic fluctuation, allowing the correlation of 22 carbon isotopic events between these sections. This high-resolution correlation greatly improves the previous micro- and macrofossil biostratigraphic schemes in the Northwest Pacific region, and reveals that global events, such as the oxygen depletion at the OAE 2 horizon, the constant decrease in pCO₂ during the Late Cretaceous, and the eustatic sea-level falls in the late middle Turonian, Santonian/Campanian Boundary and early Campanian, are recorded in the Upper Cretaceous sequence of the Northwest Pacific.  相似文献   

Comprehensive physicochemical study of dioctahedral palygorskite-rich clay from Marrakech High Atlas (Morocco)     

Benaissa Rhouta  Ezzouhra Zatile  Lahcen Bouna  Omar Lakbita  Francis Maury  Lahcen Daoudi  Marie Christine Lafont  M’Barek Amjoud  François Senocq  Amane Jada  Ahmed Aït Aghzzaf 《Physics and Chemistry of Minerals》2013,40(5):411-424

This study is devoted to the physicochemical and mineralogical characterizations of palygorskite from Marrakech High Atlas, Morocco. The raw clay and its Na⁺-saturated <2 μm fraction were characterized using chemical, structural, and thermal analytical techniques. Measurements of specific surface area and porous volume are reported. The clay fraction was found to be made up of 95 % of palygorskite and 5 % of sepiolite. An original feature of this palygorskite is its deficiency in zeolitic H₂O. The half-cell structural formula of its dehydrated form was determined on the basis of 21 oxygens to be (Si_7.92Al_0.08)(Mg_2.15Al_1.4Fe_0.4Ti_0.05 $ \square_{1} $ )(Ca_0.03Na_0.08K_0.04)O₂₁, while the hydrated form could be formulated as (Si_7.97Al_0.03)(Mg_2.17Al_1.46Fe_0.40Ti_0.05)(Ca_0.03Na_0.07K_0,03)O_20.18(OH)_1.94(OH₂)_3.88·2.43 H₂O. These formulas show that the (Al³⁺+Fe³⁺)/Mg²⁺ ratio is around 0.84, revealing a pronounced dioctahedral character. Further, inside its octahedral sheet, it was determined that the inner M₁ sites are occupied by vacancies, whereas the M₂ sites are shared between 90 % of trivalent cations (78 % for Al³⁺ and 22 % for Fe³⁺), 7.5 % of Mg²⁺, and 2.5 % of Ti⁴⁺, all of them linked to 1.94 of structural hydroxyls. The two remaining Mg²⁺ by half-cell occupy edge M₃ sites and are coordinated to 3.88 molecules of OH₂. Channels of this palygorskite are deficient in zeolitic H₂O since they contain only 2.43 H₂O molecules. A correlation was found between these results and the observation of very intense and well-resolved FTIR bands arising from dioctahedral domains (mainly Al₂OH, Fe₂OH, and AlFeOH) along with very small responses from a trioctahedral domain (Mg₃OH). Accordingly, a schematic representation of the composition of the octahedral sheet was proposed. The cation exchange capacity, specific surface area, and total pore volume were also assessed to be ca. 21.2 meq/100 g, 116 m²/g, and 0.458 cm³/g, respectively.  相似文献   

The Geochemical Context of Gas Hydrate in the Eastern Nankai Trough   总被引：1，自引：0，他引：1  

Amane Waseda  Takashi Uchida 《Resource Geology》2004,54(1):69-78

Abstract. Geochemical studies for gas hydrate, gas and organic matter collected from gas hydrate research wells drilled at the landward side of the eastern Nankai Trough, offshore Tokai, Japan, are reported. Organic matter in the 2355 m marine sediments drilled to Eocene is mainly composed of Type III kerogen with both marine and terrigenous organic input. The gas hydrate-bearing shallow sediments are immature for hydrocarbon generation, whereas the sediments below 2100 mbsf are thermally mature. The origins of gases change from microbial to thermogenic at around 1500 mbsf.
Carbon isotope compositions of CH₄ and CO₂, and hydrocarbon compositions consistently suggest that the CH₄ in the gas hydrate-bearing sediments is generated by microbial reduction of CO₂. The δ¹³C depth-profiles of CH₄ and CO₂ suggest that the microbial methanogenesis is less active in the Nankai Trough sediments compared with other gas hydrate-bearing sediments where solid gas hydrate samples of microbial origin were recovered. Since in situ generative-potential of microbial methane in the Nankai Trough sediments is interpreted to be low due to the low total organic carbon content (0.5 % on the average) in the gas hydrate-bearing shallow sediments, upward migration of microbial methane and selective accumulation into permeable sands should be necessary for the high concentration of gas hydrate in discrete sand layers.  相似文献   

Geochemical characteristics of crude oils from the Sagara oil field, Shizuoka Prefecture, Japan     

Susumu  Kato  Amane  Waseda  Hideki  Nishita 《Island Arc》2006,15(3):304-312

Abstract   Six oil samples collected from the Sagara oil field, Shizuoka Prefecture, were geochemically analyzed. Unlike the Niigata oils, the Sagara oils: (i) are low-sulphur light oils dominated by gasoline and kerosene fractions; (ii) have low values of environment index in light hydrocarbon compositions; (iii) have high Pr/ n -C₁₇ and low Ph/ n -C₁₈ ratios and high oleanane/hopane ratios; (iv) have high relative abundance of C₂₉ and low relative abundance of C₂₈ regular steranes; and (v) have 'light' stable carbon isotope compositions. These characteristics show that the source rocks of the Sagara oils contain mainly marine organic matter, but with more input of terrigenous organic matter deposited under more oxic conditions compared to those of the Niigata oils. The light carbon isotope compositions and the low relative abundance of C₂₈ regular steranes of the Sagara oils suggest that their source rock is not Miocene, but probably Paleogene in age. The Sagara oils probably migrated along faults from deeper parts of the basin.  相似文献   

Geochemical characteristics of Tertiary oils derived from siliceous sources in Japan, Russia and U.S.A.     

Alexander Chakhmakhchev  Masaru Suzuki  Amane Waseda  Kuniaki Takayama 《Organic Geochemistry》1997,27(7-8)

Siliceous sourced Tertiary oils from the Circum-Pacific area of Japan, Russia and the U.S.A. have a heavy carbon isotope composition, monomodal n-alkane distributions, and nearly identical regular sterane compositions with a predominance of C₂₇ homologues. These are consistent with open marine depositional environments dominated by diatomaceous organic matter. However, a number of alkane and biomarker parameters such as Pr/Ph, CPI, relative concentration of 28,30-bisnorhopane, and the C₃₅/C₃₄ homohopane ratio indicate more oxic depositional environments for the source rocks of Japan and Russia. In contrast to the California Monterey Formation sourced oils, petroleums with low maturity levels from the North Sakhalin basin, Russia and the Akita basin, Japan have lower concentrations of asphaltenes and sulphur and are characterized by higher API gravities. A correlation of extractable organic matter from source rocks vs the least matured petroleums demonstrates that oil expulsion in siliceous shales of the Akita basin occurs at a maturity level corresponding to R_o≥0.65%, which is in the range of the conventional oil window (R_o = 0.6−1.1%).  相似文献