腐殖酸对矿物结合汞活性的影响I. 腐殖酸对矿物结合汞挥发活性的影响

挥发试验结果表明,试验条件下,富里酸能极显著地促进Fe2O3-Hg,MnO2-Hg与高岭土结合汞的挥发,对膨润土结合汞和碳酸钙结合汞的挥发则表现抑制作用.棕色胡敏酸能促进各矿物结合汞的挥发.灰色胡敏酸影响最为微弱.腐殖酸对矿物结合态汞挥发性的影响与其对汞的络合容量与络合稳定性,矿物对汞的吸持特性,以及矿物与腐殖酸的作用特性密切相关.     

腐殖酸对矿物结合汞活性的影响研究Ⅱ．腐殖酸对矿物结合汞挥发活性影响的动态特征

汞的挥发动力学表明：腐殖酸对矿物结合汞活性兼具抑制与活化的双重效应,突出表现为对矿物结合汞的挥发具有先期抑制与后期活化最后趋于稳定的动态影响特征,其效应具长期性渐变特点。不同腐殖酸针对不同矿物类型结合汞,其作用速率与强度不同。     

腐殖酸对矿物结合汞活性的影响研究──Ⅱ.腐殖酸对矿物结合汞挥发活性影响的动态特征

汞的挥发动力学表明：腐殖酸对矿物结合汞活性兼具抑制与活化的双重效应,突出表现为矿物结合汞的挥发具有先期抑制与后期活化最后趋于稳定的动态影响特征,其效应具有长期性渐变特点。不同腐殖酸针对不同矿物类型结合汞,其作用速率与强度不同。     

腐殖酸对汞的络合稳定特性及其环境学意义

对3种腐殖酸与Hg的络合稳定特性研究结果表明,腐殖酸与Hg的结合存在松结态与紧结态2种形态,其中富里酸主要以松结态为主,灰色胡敏酸与棕色胡敏酸则以紧结态占绝对优势。3种腐殖酸中富里酸对Hg的络合容量最高,但络合强度最低,其络合汞的环境活性将较高;灰色胡敏酸对Hg的络合容量最低,但络合稳定性最高,故所结合Hg的环境活性最弱。但受容量因素制约,灰色胡敏酸对Hg的络合稳定性将因Hg/灰色胡敏酸相对比例的升高而急剧下降。棕色胡敏酸对Hg络合特性介于富里酸与灰色胡敏酸之间。     

饱和硫化钠对土壤HgS提取的专性质疑

通过饱和硫化钠（ｓｓ－Ｎａ２Ｓ）对Ｆｅ２Ｏ３－Ｈｇ，ＭｎＯ２－Ｈｇ，高岭土－Ｈｇ和膨润土－Ｈｇ的提取试验，对ＨｇＳ形成条件的理论探讨，以及ｓｓ－Ｎａ２Ｓ提取态汞能为ＣａＣＯ３、腐殖酸、膨润土等所抑制的试验结果，证明了Ｎａｔｈａｎｉｅｌ（１９８９）提出的土壤ＨｇＳ的专性提取剂－ｓｓ－Ｎａ２Ｓ并不具备专性，它能强烈提取各种土壤矿物结合态汞。采用ｓｓ－Ｎａ２Ｓ作为土壤ＨｇＳ的提取剂将会过高估计ＨｇＳ在环     

腐殖酸对灰棕紫泥中汞赋存形态的影响

通过室内培养探讨不同富里酸/胡敏酸(FA/HA)、腐殖酸含量、汞污染浓度对灰棕紫泥中汞赋存形态的影响。结果表明,施用腐殖酸降低汞的活性,腐殖酸各处理均能促进土壤中水溶态、交换态和酸溶态汞向碱溶态、有机结合态和残渣态汞转化。FA/HA≤0.7时,腐殖酸能够促进土壤中的活性态汞向惰性态汞转化,但当FA/HA≥1时,腐殖酸对土壤汞有一定的活化作用;含碳2%的腐殖酸对土壤汞的固定效果好于其他碳含量(0.5%,1%,1.5%碳)腐殖酸;当土壤中汞污染浓度达到3mg/kg时,腐殖酸对汞的固定效果要降低。     

腐殖酸对矿物结合汞活性的影响

挥发试验结果表明,试验条件下,富里酸能极显著地促进Fe     

土壤矿物对汞的吸持特性研究

吸附热力学与动力学试验研究结果表明 ,5种土壤矿物对Hg的吸附容量与吸附强度均表现为MnO2 >Fe2 O3 >膨润土 >高岭土 >CaCO3 。MnO2 对Hg吸附容量大且固持能力强 ,CaCO3 则与之相反。各土壤矿物结合汞的形态分布特征表明各土壤矿物结合汞在不同环境的稳定性及相应数量比例。挥发试验结果表明各土壤矿物结合汞的环境活性 (挥发活性 )大小受土壤矿物对Hg吸附容量与吸附强度制约 ,并与矿物结合汞的形态分布特征相关 ,水溶交换态和酸溶态比例越高则土壤矿物结合汞挥发活性越强 ,碱溶态和残渣态比例越高则土壤矿物结合汞挥发活性相应越弱     

腐殖酸对浑河流域草甸土钾素吸附特性的影响研究

草甸土是辽宁地区的主要农业土壤,但是草甸土中含有大量的2∶1型黏土矿物,这些矿物具有固钾能力,受这些矿物的影响,草甸土具有较强的固钾能力,较大程度上限制了外源钾素的发挥。采用连续流动法研究了腐殖酸对浑河流域发育的草甸土钾素固定与释放的影响,结果表明,施用腐殖酸能够降低土壤对钾素的固定量。腐殖酸对土壤固钾率的影响与腐殖酸和钾的施入顺序有关,在外源钾(800 mg kg-1)存在时腐殖酸提前于钾素一天施入,与未加腐殖酸相比能引起溶液钾的显著增加,其中胡敏酸增加41.8%,富里酸增加56.3%;腐殖酸与钾素同时加入,也能引起溶液钾的增加,但增加幅度降低,其中胡敏酸增加7.3%。富里酸增加26.2%;腐殖酸后于钾素加入,引起的溶液钾变化较小,其中胡敏酸增加5.5%,富里酸增加9.8%。三种施入方式对交换钾变化影响不大。不同施入方式下土壤的固钾率表现为:未加腐殖酸后加腐殖酸同时加入先加腐殖酸。     

腐殖酸结合东的研究现状

综述了近２０年来国内外对腐殖酸结合汞的研究成果,腐殖酸在土壤中虽然含量不高,但结合汞的容量大,且结合汞后有一定的活性,并指出,人们对腐殖酸结合汞是抑制还是活化土壤东的认识分歧在于腐殖酸组分对东的络合能力和合合物稳定性存在差异。     

Effect of Humus on Activity of Mineral-Bound Hg: III.Effect on Leachability and Transfer of Mineral-Bound Hg Under Acid Leaching Condition

Effects of humus fractions (fulvic acid, brown humic acid and grey humic acid) on the leachability and transferring activity of five types of mineral-bound Hg were investigated. Under the acid leaching condition; fulvic acid could promote leachability and vertical transference of all the mineral-bound Hg. Brown humic acid could retard the leaching and transferring processes of CaCO3-Hg, Fe2O3-Hg, MnO2-Hg and kaolinite Hg but not bentonite-Hg. Grey humic acid could greatly enhance residing ability of the mineral-bound Hg in the soil column and restrain them from vertical transferring. The effect of humus on leachability and transferring activity on the mineral-bound Hg was closely related to its ability to convert the mineral-bound Hg into organic-bound form and the transferability of the latter in the soil column. The characteristics of the mineral-bound Hg in speciation were the internal factors that determined the extent and rate of the influence of the humus.     

土壤硼的电化学特征及解吸动力学

Effects of humus fractions (fulvic acid,brown humic acid and grey humic acid) on the leachability and transferring activity of five types of mineral-bound Hg were investigated.Under the acid leaching condition;fulvic acid could promote leachability and vertical transference of all the mineral-bound Hg.Brown humicacid could retard the leaching and trasferring processes of CaCO30-Hg,Fe2O3-Hg,MnO2-Hg and kaolinite Hg but not bentonite-Hg.Grey humic acid could greatly enhance residing ability of the mineral-bound Hg in the soil colum and restrain them from vertical transferring.The effect of humus on leachability and transferring activity on the mineral-bound Hg was closely related to its ability to convert the mineral-bound Hg into orgainc-bound form and the transferbility of the latter in the soil column.The characteristics of the mineral-bound Hg in speciation were the internal factors that determined the extent and rate of the influence of the humus.     

长期施用有机肥料对紫色水稻土有机无机复合性状的影响

连续九年施用有机肥料，紫色水稻土壤及＜０．００２ｍｍ的有机无机复合体中无定形铁，铝和铬合态铁，铝的含量呈不同程度的增加，铬合态铁和铝间具拮抗作用（ｒ＝０．７９９８ｎ＝７）；土壤的有机质含量增加主要是由于轻组有机质含量增加，而有机无机复合度下降，土壤重组腐殖质的含量为０．２５－０．０１ｍｍ＞＜０．００２ｍｍ＞１－０．２５ｍｍ＞０．０１－０．００２ｍｍ；有机无机复合度及重组腐殖质中松结态与紧结态的比值     

Permanganate oxidation of methylated and non-methylated aquatic humus in Norway

The chemical composition of aquatic humus was investigated by permanganate oxidation. Both methylated and non-methylated samples were investigated and the results compared with those of different soil humic fractions investigated earlier.The total amount of oxidation products identified from the methylated sample was 2%, and from the non-methylated sample 0.9%. The composition of the oxidation products from methylated aquatic humus was 42% benzenecarboxylic acid methyl esters (8 different compounds), 43% methoxy-benzenecarboxylic acid methyl esters (12 compounds), 10% dimethoxy-benzenecarboxylic acid methyl esters (4 compounds), and 5% of 1, 2, 3-propanetricarboxylic acid trimethyl ester. The unmethylated aquatic humus yielded 84% benzenecarboxylic acid methyl ester (7 compounds), 7% methoxy-benzenecarboxylic acid methyl esters (2 compounds), and 9% of 1, 2, 3-propanetricarboxylic acid trimethyl ester. Three diazines isolated from methylated material were believed to be artefacts from diazomethane treatment. Two of the diazines have earlier been found by oxidation of methylated soil samples, the third, C₁₀H₁₂N₂O₆, is an oxidation product of methylated aquatic humus only.Oxidation of aquatic humus yielded more benzenecarboxylic acids and methoxy-benzenecarboxylic acids than soil humic fractions, and less dimethoxy-benzenecarboxylic acids. No aliphatic dicarboxylic acids were detected among the oxidation products of the aquatic humus.The compounds identified are mainly the same as those found by oxidation of different soil humic fractions, although their yields clearly demonstrated that the aquatic humus differed in composition from the soil fractions.     

大兴安岭北部的灰化土

大兴安岭北部,即伊勒呼里山以北的大兴安岭主体部分,大致位于北纬51°20'—53°28',东经121°31'—126°30'之间,是我国的最北端。其地带性土壤类型,过去说法不一,曾有人命名为生草灰化土¹⁾、棕色灰化土、棕色泰加林土²⁾、灰白色森林土(中国科学院内蒙古宁夏综合考察队等,1978)、棕色针叶林土³⁾、漂灰土(中国科学院南京土壤研究所主编,1978)等。     

RADIOCARBON DATING OF PALEOSOLS USING SOIL ORGANIC MATTER COMPONENTS

Soil organic matter components of classical humic acid and humic fractions were extracted from two paleosols using 0.1 M Na₄ P₃ O₂:0.1 M NaOH. These fractions were subjected to chemical treatment with 6 M HC1 or 70 per cent HNO, before radiocarbon assay, and their radiocarbon dates were compared with those of similar but untreated fractions, untreated buried soils, and previously published charcoal dates. Hydrolysis of humic acid and humin fractions with mineral acids, particularly 70 per cent HNO₃ led to older radiocarbon dates, comparable to, though slightly older than, those of charcoal derived from the same buried layers. In contrast, the dates of soils and their humic acid and humin fractions before acid hydrolysis were younger and therefore less reliable. The application of this procedure to studies of paleosols in New Zealand is discussed.     

作物秸秆碳在土壤中分解和转化规律的研究

采用14C标记秸秆,在大田和实验室的研究结果表明,秸秆的分解速率主要取决于C/N比。施入土壤后,土壤微生物迅速增加,尤其是细菌。秸秆降解首先形成非结构物质,其中大部分转化为富里酸,进而转化为胡敏酸。分解产物对土壤腐殖质的更新,从腐殖质表面官能团或分子断片开始,逐步进行。非结构物质可与腐殖酸的单个分子产生交联作用,在一定条件下,交联的复合分子可进入腐殖质分子核心的成分中。腐殖酸单个组分在土壤中的转化和重新分配,仅仅与腐殖质表面官能团的反交换过程密切相关。粘土矿物选择性吸附胡敏酸,而且优先吸附胡敏酸中低分子成分。