COAGULATION OF HUMIC COLLOIDS BY METAL IONS
COAGULATION OF HUMIC COLLOIDS BY METAL IONS
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金属离子对腐殖质胶体的凝固作用
DOI：
10.1097/00010694-196809000-00011
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发表时间：
1968
期刊：
影响因子：
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通讯作者：
R. E. Bisque
中科院分区：
文献类型：
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作者：
H. L. Ong;R. E. Bisque
用泥炭碱溶部分(ASF)代表可溶腐殖质，研究了金属与有机物质之间的相互作用。对冷冻干燥后的标准ASF进行了元素分析和红外分析。其组成与从不同地区不同土层中提取的有机质的平均组成相似。LYOPHILIZED标准ASF的红外光谱包含一些指示羟基和羧基的尖锐谱带，与许多土壤有机提取物的光谱相似。通过将产生沉淀的试管中的浓度与未检测到沉淀的后续试管中的浓度之间的值进行内插来确定电解液的凝固值或临界浓度。泥炭碱可溶部分与添加一价离子(锂、钠和钾)、二价离子(镁和钙)和三价离子(铁、铝和砷)的混凝研究表明：(1)实现混凝所需的一价离子、二价离子和三价离子的量与理论值基本一致，(2)对于单价或二价离子，凝聚力随着水合离子半径的减小而增加。这种碱溶组分可被认为是一种负亲水胶体或聚电解质，金属-有机缔合的稳定性可用福斯效应和胶体凝聚的双层理论解释。结果表明，胶体过程可能是PODZOLIZATION中金属迁移的主要原因，这种迁移通常归因于络合和配位络合物。
METAL-ORGANIC INTERACTIONS WERE STUDIED USING AN ALKALI SOLUBLE FRACTION OF PEAT (ASF) TO REPRESENT THE SOLUBLE HUMIC SUBSTANCES. ELEMENTAL AND INFRARED ANALYSES OF THE STANDARD ASF WERE MADE AFTER FREEZE-DRYING THE SOLUTION. THE COMPOSITION WAS SHOWN TO BE SIMILAR TO THE AVERAGE COMPOSITION OF ORGANIC MATTER EXTRACTED FROM VARIOUS SOIL HORIZONS FROM MANY DIFFERENT LOCALITIES. INFRARED SPECTRA OF THE LYOPHILLIZED STANDARD ASF CONTAIN A FEW SHARP BANDS INDICATING HYDROXYL AND CARBOXYL FUNCTIONAL GROUPS, SIMILAR TO THE SPECTRA OF MANY SOIL ORGANIC EXTRACTS. COAGULATION VALUE OR CRITICAL CONCENTRATION OF AN ELECTROLYTE WAS DETERMINED BY INTERPOLATING THE VALUE BETWEEN THE CONCENTRATION IN THE TEST TUBE THAT PRODUCED PRECIPITATION AND THE CONCENTRATION IN THE SUBSEQUENT TUBE WHERE NO PRECIPITATION COULD BE DETECTED. COAGULATION STUDIES INVOLVING THE ALKALI'S SOLUBLE FRACTION OF PEAT WITH ADDED MONOVALENT IONS (LITHIUM, SODIUM AND POTASSIUM), DIVALENT IONS (MAGNESIUM AND CALCIUM), AND TRIVALENT IONS (IRON, ALUMINUM, AND ASSISIUM) DEMONSTRATED THE FOLLOWING: (1) THE AMOUNT OF MONOVALENT, DIVALENT, AND TRIVALENT IONS REQUIRED TO EFFECT COAGULATION GENERALLY AGREES WITH THE THEORETICAL, AND (2) FOR MONOVALENT OR DIVALENT IONS, THE COAGULATING POWER INCREASES AS THE RADIUS OF THE HYDRATED ION DECREASES. THIS ALKALI SOLUBLE FRACTION OF PEAT CAN BE CONSIDERED AS A NEGATIVE HYDROPHILIC COLLOID OR A POLYELECTROLYTE AND THE STABILITY OF METAL-ORGANIC ASSOCIATIONS CAN BE EXPLAINED BY THE FUOSS EFFECT AND THE DOUBLE-LAYER THEORY OF COLLOID COAGULATION. IT IS CONCLUDED THAT THE COLLOIDAL PROCESS MAY BE RESPONSIBLE FOR MUCH OF THE METAL TRANSPORT IN PODZOLIZATION THAT IS OFTEN ATTRIBUTED TO CHELATION, AND COORDINATION COMPLEXES.