{"@context":{"@vocab":"https://cir.nii.ac.jp/schema/1.0/","rdfs":"http://www.w3.org/2000/01/rdf-schema#","dc":"http://purl.org/dc/elements/1.1/","dcterms":"http://purl.org/dc/terms/","foaf":"http://xmlns.com/foaf/0.1/","prism":"http://prismstandard.org/namespaces/basic/2.0/","cinii":"http://ci.nii.ac.jp/ns/1.0/","datacite":"https://schema.datacite.org/meta/kernel-4/","ndl":"http://ndl.go.jp/dcndl/terms/","jpcoar":"https://github.com/JPCOAR/schema/blob/master/2.0/"},"@id":"https://cir.nii.ac.jp/crid/1363670321068322816.json","@type":"Article","productIdentifier":[{"identifier":{"@type":"DOI","@value":"10.1046/j.1365-2389.2000.00295.x"}},{"identifier":{"@type":"URI","@value":"https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1046%2Fj.1365-2389.2000.00295.x"}},{"identifier":{"@type":"URI","@value":"https://bsssjournals.onlinelibrary.wiley.com/doi/pdf/10.1046/j.1365-2389.2000.00295.x"}}],"dc:title":[{"@value":"Interactions of allophane with humic acid and cations"}],"description":[{"type":"abstract","notation":[{"@value":"<jats:title>Summary</jats:title>\n                  <jats:p>\n                    Allophanic soils are known to accumulate organic matter, but the underlying mechanism is not well understood. Here we have investigated the sorption of humic acid (HA) by an allophanic clay in the presence of varied concentrations of either CaCl\n                    <jats:sub>2</jats:sub>\n                    or NaCl as background electrolytes. Both the HA and the clay were separated from New Zealand soils. Much more HA was sorbed in CaCl\n                    <jats:sub>2</jats:sub>\n                    than in NaCl of the same ionic strength. Apparently Ca\n                    <jats:sup>2+</jats:sup>\n                    ions were more effective than Na\n                    <jats:sup>+</jats:sup>\n                    ions in screening the negative charge on HA. In CaCl\n                    <jats:sub>2</jats:sub>\n                    the HA molecule might also assume a more compact configuration than in NaCl. In the presence of CaCl\n                    <jats:sub>2</jats:sub>\n                    sorption increased, reached a maximum, and then declined as the concentration of HA in solution was increased. This behaviour was not observed in NaCl where sorption showed a gradual and steady increase with HA concentration. We propose that ligand exchange occurs between the surface hydroxyl groups of allophane and the carboxylate groups of HA. As a result, the allophane–HA complex acquires negative charges, requiring the co‐sorption of extraneous cations (Ca\n                    <jats:sup>2+</jats:sup>\n                    or Na\n                    <jats:sup>+</jats:sup>\n                    ) for charge balance. The Ca\n                    <jats:sup>2+</jats:sup>\n                    co‐sorbed can attract more HA to the complex possibly by a cation‐bridging mechanism, giving rise to a maximum in sorption. The decline in sorption beyond the maximum may be ascribed to a decrease in the concentration of free Ca\n                    <jats:sup>2+</jats:sup>\n                    ions through binding to HA molecules in solution. The increase in supernatant pH may be attributed to a ligand exchange reaction between the surface hydroxyls of allophane and the carboxylate groups of HA, and proton binding to the allophane–HA complex.\n                  </jats:p>"}]}],"creator":[{"@id":"https://cir.nii.ac.jp/crid/1383670321068322816","@type":"Researcher","foaf:name":[{"@value":"G. Yuan"}]},{"@id":"https://cir.nii.ac.jp/crid/1383670321068322690","@type":"Researcher","foaf:name":[{"@value":"B. K. G. Theng"}]},{"@id":"https://cir.nii.ac.jp/crid/1383670321068322689","@type":"Researcher","foaf:name":[{"@value":"H. J. Percival"}]},{"@id":"https://cir.nii.ac.jp/crid/1383670321068322688","@type":"Researcher","foaf:name":[{"@value":"R. L. Parfitt"}]}],"publication":{"publicationIdentifier":[{"@type":"PISSN","@value":"13510754"},{"@type":"EISSN","@value":"13652389"}],"prism:publicationName":[{"@value":"European Journal of Soil Science"}],"dc:publisher":[{"@value":"Wiley"}],"prism:publicationDate":"2000-03","prism:volume":"51","prism:number":"1","prism:startingPage":"35","prism:endingPage":"41"},"reviewed":"false","dc:rights":["http://onlinelibrary.wiley.com/termsAndConditions#vor"],"url":[{"@id":"https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1046%2Fj.1365-2389.2000.00295.x"},{"@id":"https://bsssjournals.onlinelibrary.wiley.com/doi/pdf/10.1046/j.1365-2389.2000.00295.x"}],"createdAt":"2003-03-11","modifiedAt":"2025-10-31","relatedProduct":[{"@id":"https://cir.nii.ac.jp/crid/1360004232051915520","@type":"Article","resourceType":"学術雑誌論文(journal article)","relationType":["isReferencedBy"],"jpcoar:relatedTitle":[{"@value":"Characterization of an adsorbed humin-like substance on an allophanic soil formed via catalytic polycondensation between catechol and glycine, and its adsorption capability to pentachlorophenol"}]},{"@id":"https://cir.nii.ac.jp/crid/1360017279846056192","@type":"Article","resourceType":"学術雑誌論文(journal article)","relationType":["isReferencedBy"],"jpcoar:relatedTitle":[{"@value":"Synthesis of allophane from rice husk ash and its use as a phosphate adsorbent: A novel approach"}]},{"@id":"https://cir.nii.ac.jp/crid/1363383604714033024","@type":"Article","resourceType":"学術雑誌論文(journal article)","relationType":["isReferencedBy"],"jpcoar:relatedTitle":[{"@value":"Control of climate on soil charge characteristics through organic matter and clay mineral distributions in volcanic soils of Mt. Kilimanjaro, Tanzania"}]},{"@id":"https://cir.nii.ac.jp/crid/1390001205287675008","@type":"Article","resourceType":"学術雑誌論文(journal article)","relationType":["isReferencedBy"],"jpcoar:relatedTitle":[{"@language":"en","@value":"Tuning of calcium silicate ceramics for environment-friendly material applications"}]},{"@id":"https://cir.nii.ac.jp/crid/1521136279902432512","@type":"Article","relationType":["isReferencedBy"],"jpcoar:relatedTitle":[{"@value":"Characterization of Water-Soluble Organic Matter in Soils by Size Exclusion Chromatography and Fractionation with Polyvinylpyrrolidone"},{"@language":"ja-Kana","@value":"Characterization of Water Soluble organic Matter in Soils by Size Exclusion Chromatography and Fractionation with Polyvinylpyrrolidone"}]},{"@id":"https://cir.nii.ac.jp/crid/1521417755819950848","@type":"Article","relationType":["isReferencedBy"],"jpcoar:relatedTitle":[{"@value":"Carbon Sequestration and Stabilization in Soils: Implications for Soil Productivity and Climate Change"},{"@language":"ja-Kana","@value":"Carbon Sequestration and Stabilization in Soils Implications for Soil Productivity and Climate Change"}]}],"dataSourceIdentifier":[{"@type":"CROSSREF","@value":"10.1046/j.1365-2389.2000.00295.x"},{"@type":"CROSSREF","@value":"10.1016/j.jece.2022.108634_references_DOI_KjeeWBDkyxfT7tYKDmap9hrZIdU"},{"@type":"CROSSREF","@value":"10.1080/00380768.2002.10409229_references_DOI_KjeeWBDkyxfT7tYKDmap9hrZIdU"},{"@type":"CROSSREF","@value":"10.1080/00380768.2004.10408502_references_DOI_KjeeWBDkyxfT7tYKDmap9hrZIdU"},{"@type":"CROSSREF","@value":"10.2109/jcersj2.122.858_references_DOI_KjeeWBDkyxfT7tYKDmap9hrZIdU"},{"@type":"CROSSREF","@value":"10.1016/j.chemosphere.2011.01.053_references_DOI_KjeeWBDkyxfT7tYKDmap9hrZIdU"},{"@type":"CROSSREF","@value":"10.1080/00380768.2021.1883998_references_DOI_KjeeWBDkyxfT7tYKDmap9hrZIdU"}]}