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1.
冻融作用对棕壤磷素吸附-解吸特性的影响 总被引：7，自引：0，他引：7
以棕壤为研究对象,采用室内模拟冻融环境的方法,研究土壤磷素吸附-解吸行为,采用Langumuir、Freundlich和Temkin方程对吸附过程进行拟合分析,定量研究冻融作用对土壤磷素吸附机制的影响,同时建立土壤磷素解吸量与吸附量关系方程,进一步探讨冻融土壤磷吸附-解吸特性。结果表明,冻融条件下棕壤对磷的吸附规律一致,吸附量均随着平衡溶液中磷浓度增加而逐渐增大,与未冻融土壤相比,冻融后土壤磷等温吸附曲线变得平缓。冻融条件下磷等温吸附曲线用Langmuir方程拟合相关性最好。土壤磷素解吸量与相应最大吸附量符合线性相关。冻融后土壤磷固定吸附量低于未冻融土壤,即冻融过程促进土壤磷素释放,增加了土壤磷流失风险。多次冻融循环对土壤磷吸附-解吸行为影响更为强烈。 相似文献
2.
白浆土是吉林省和黑龙江省东部地区的主要农田土壤之一,研究白浆土对腐殖酸的吸附作用,可为探究白浆土的固碳潜力提供理论依据。采用批量平衡法,分析不同有机碳含量的白浆土及其组分(包括去有机质土壤、粉粒、黏粒)对腐殖酸的吸附动力学和等温吸附特性。结果表明:随吸附时间的延长,白浆土及其各组分对腐殖酸的吸附量逐渐增加;整个吸附动力学过程可划分为快速(0～30 min)和慢速(30～480 min)反应阶段,伪二级动力学方程的拟合效果优于Elovich、双常数和伪一级动力学方程。白浆土及其各组分对腐殖酸的吸附量随腐殖酸初始浓度的增加逐渐增大,Langmuir方程的拟合效果通常优于Freundlich方程和Temkin方程。随白浆土有机碳含量的增加,其对腐殖酸的最大吸附量分别为26.9,24.1,15.6 mg/g。而白浆土不同组分相比,最大吸附量的顺序依次为黏粒>去有机质土壤>粉粒,黏粒对腐殖酸的吸附量分别是原土的2.15～3.88倍,去有机质土壤的1.61～2.21倍,粉粒土壤的7.90～8.65倍。有机碳含量低的白浆土对腐殖酸具有更强的吸附能力,黏粒含量高的白浆土对腐殖酸的吸附潜力更大。 相似文献
3.
玉米秸秆是一种重要的有机物料,它能通过表观吸附过程(包括物理吸附和化学反应过程)降低Cr(VI)污染。本试验采用间歇振荡法,初步研究了玉米秸秆对Cr(VI)的表观吸附动力学和等温线,并用吸附方程进行拟合。结果表明:玉米秸秆对Cr(VI)的表观吸附动力学以一级动力学方程为最优方程;表观吸附等温线可用Freundlich、Langmuir和Temkin方程描述,而以Freundlich方程的拟合效果最好;土壤或水体中的Cr(VI)含量越高,玉米秸秆的修复效果越差。 相似文献
4.
玉米秸秆是一种重要的有机物料，它能通过表观吸附过程(包括物理吸附和化学反应过程)降低Cr(VI)污染。本试验采用间歇振荡法，初步研究了玉米秸秆对Cr(vi)的表观吸附动力学和等温线，并用吸附方程进行拟合。结果表明：玉米秸秆对Cr(vi)的表观吸附动力学以一级动力学方程为最优方程；表观吸附等温线可用Freundlich、Langmuir和Temkin方程描述，而以Freundlich方程的拟合效果最好；土壤或水体中的Cr(VI)含量越高，玉米秸秆的修复效果越差。 相似文献
5.
Langmuir,Temkin和Freundlich方程应用于土壤吸附锌的比较 总被引：21，自引：0，他引：21
本文分别用Langmuir,Temkin和Freundlich方程拟合土壤吸附锌的等温线。结果表明,吸附数据能很好地符合Freunblich方程,而Langmuir和Temkin方程拟合程度较差。作者从吸附热角度证明了土壤表面不均匀性是造成这种差别的最主要因子。土壤吸附锌过程中吸附热与吸附量的关系满足Freundlich方程模型中关于能量的假设。所以Freundlich方程能比较真实地反映土壤吸附锌的本质,可用予锌吸附机制的探讨。 相似文献
6.
7.
《水土保持学报》2014,(3)
在温室条件下采用盆栽试验方法在4类典型土壤上种植小白菜,以自来水灌溉作为对照,研究再生水灌溉对小白菜生长、土壤磷形态转化特征以及不同类型土壤间的差异性。结果表明,全再生水灌溉:①显著增加红壤、潮土、塿土小白菜生物量,分别为9.1%,16.1%,9.9%;黑土小白菜生物量增加不显著;②显著增加4类土壤小白菜地上部磷含量和土壤速效磷含量,红壤、潮土、塿土和黑土的小白菜地上部磷含量分别增加17.6%,20.0%,18.8%和15.8%,土壤速效磷含量分别增加16.7%,32.2%,34.4%,16.8%;③显著增加红壤、潮土、塿土的活性有机磷和无机磷组分中活性较高的Ca2-P,黑土的Ca2-P含量显著增加,但其活性有机磷含量变化不大。再生水灌溉能促进土壤稳性较高的有机、无机磷组分向活性较高的组分转化,但不同类型土壤间存在差异性。 相似文献
8.
萘在土壤上的吸附行为及温度影响的研究 总被引：2，自引：0，他引：2
采用批量平衡法研究了多环芳烃萘在塿土耕层土、塿土粘化层土、塿土古土壤、黄壤、紫色土和石灰土上的吸附行为,比较了不同吸附模型方程对实验数据的拟合情况,并探讨了温度对萘在土壤上吸附行为的影响机理及吸附热力学特征。Henry模型、Freundlich模型和deBoer-Zwikker极化模型均能较好地拟合萘的吸附等温线;45℃下的吸附等温线明显地高于25℃的吸附等温线,表现出随温度升高吸附量增大的趋势。Freundlich模型的吸附容量参数Kf和deBoer-Zwikker模型的起始吸附势ε0在两个温度下有极显著的差异;但Freundlich模型的n参数表征了土壤颗粒表面的性质,对温度变化不敏感。在25℃条件下,萘在土壤有机碳上的分配可能是吸附的主要机制,但随着温度增加,吸附机制变得复杂。土壤对萘的吸附是一吸热反应,整个吸附体系中熵增是吸附作用进行的主要驱动力。 相似文献
9.
以平衡吸附法研究了塿土对阴离子表面活性剂（SDS）、非离子表面活性剂（TritonX-100、Tween80和Brij35）的吸附特征,考察了pH、阴-非离子表面活性剂混合对塿土吸附表面活性剂的影响。结果表明,非离子表面活性剂在塿土上吸附等温线均呈L型,且均符合Freundlich和Langmuir方程;塿土对SDS的吸附等温线呈LS型,可用Freundlich方程来描述;塿土对4种表面活性剂吸附量的大小顺序为Tween80〉SDS〉Brij35〉TritonX-100。当阴-非离子表面活性剂一起进入土壤中,SDS-Brij35之间的相互影响不大;TritonX-100与SDS相互作用较大,无论二者以何种方式混合都会使TritonX-100在塿土上的吸附量增加,SDS的吸附量下降;SDS与Tween80之间的相互作用最大,混合后吸附量均下降,但Tween80吸附量降低的幅度最大。pH对非离子表面活性剂的吸附影响不大,而随着pH的增加,塿土对SDS的吸附百分率明显下降;在pH为8.0时,塿土对非离子表面活性剂的吸附百分率达到80以上。因此在选择合适的表面活性剂进行有机污染土壤修复和治理时,考虑土壤的特性和表面活性剂的结构是非常重要的。 相似文献
10.
我国4种土壤磷素淋溶流失特征 总被引：5，自引：1，他引：4
磷素是水体富营养化的主要限制因子,地表水磷的污染负荷主要来源于农业面源污染。采集黑土、潮土、红壤和水稻土4种土壤,采用土柱模拟的试验方法,研究磷素在4种土壤剖面中空间分布特征,以及土壤渗漏液中TP、TDP的含量、动态变化以及流失量特征。结果表明:(1)不同类型土壤全磷和有效磷含量差异性显著,由高到低依次为水稻土潮土黑土红壤;黑土、红壤和水稻土土壤全磷和有效磷含量都表现出,随土壤深度的增加,不断降低;而潮土剖面呈上下层高,中间低的分布格局。(2)4种土壤渗漏液中占主导的磷形态不一致,潮土以MRP占主导,黑土和水稻土以DOP为主,而红壤则以PP为主。土壤磷素动态变化方面,潮土表现为TP含量先减后增再减,TDP含量先增后减;黑土表现为TP含量先增后减,TDP含量持续下降;红壤和水稻土TP和TDP含量变化不显著。(3)相关分析表明,4种土壤中Olsen-P与渗漏液中TP呈指数关系,具有极显著相关性。(4)4种土壤TP、TDP下渗流失量都以潮土最高,其次是黑土和水稻土,红壤流失量最小,磷素流失以TDP为主。 相似文献
11.
采用原位原子力显微镜智能模式初步观察了弱酸性土壤腐殖酸分子在层状硅酸盐含钾矿物黑云母表面的吸附动态和形貌变化。采用纯化、干燥后的腐殖酸固体样品配制p H 6.0,浓度分别为0 mg L-1、100 mg L-1和1000 mg L-1的腐殖酸溶液。原位观察所用的矿物薄片为土壤中常见的2∶1型含钾矿物—黑云母,其化学结构式为K(Mg2.46Fe0.45Ti0.09)[Al Si3O10](OH)2。结果表明,时间尺度是影响界面上腐殖酸形貌结构的一个重要因素。在通入p H 6.0的腐殖酸溶液作用下,原位反应0~180min内,腐殖酸分子与黑云母(001)面的相互作用以吸附为主并伴随脱附现象,吸附的腐殖酸呈球状,为单个或多个腐殖酸分子的聚集体,高度介于1~5 nm之间;原位反应180~300 min内,黑云母(001)面上吸附的腐殖酸仍以颗粒态为主,高度介于3~5 nm之间,平均为4 nm;而黑云母(001)面上的台阶和边缘位置则分布有较多的片状结构以及黑云母线型边缘诱导产生的链状结构腐殖酸聚集体,其高度介于6~8 nm,较颗粒态腐殖酸的聚集体平均高出约2.5 nm。此外,腐殖酸分子不仅能够在黑云母表面进行吸附和脱附作用,还能够溶解黑云母的表面结构,促进层间K及结构单元内Al和Si的释放。因此,腐殖酸与云母类矿物的界面反应是一个溶解—吸附—聚集并伴随着脱附和离子释放的过程。 相似文献
12.
腐植酸的组成结构及其对作物根系调控的研究进展 总被引：2，自引：0，他引：2
[目的]综述腐植酸的结构及其对作物根系调控方面的研究进展,为腐植酸的进一步资源化利用提供理论依据.[主要进展]1)腐植酸结构复杂、功能多样,由C、H、O、N和S等元素构成.腐植酸是多价酚型芳香族化合物与氮化合物的缩聚物,其裂解产物主要有烷烃类、饱和醇类、非饱和线性醇类、吡啶类等,其形成机制主要基于氨基糖缩合理论、多酚理... 相似文献
13.
I. V. Chistyakov S. Ya. Trofimov L. V. Lysak A. A. Stepanov 《Moscow University Soil Science Bulletin》2013,68(1):48-52
By gel filtration on Sephadex G-50 and G-75, we investigated the changes in the composition and ratio of the molecular fractions of humic acids under the influence of native soil microbial complexes. The highest degree of decomposition of the initial humic acid was observed when ammonium nitrate was used as a source of additional energy in the mineral nutrient medium without a yeast extract. The appearance of a low molecular fraction of organic substances on chromatograms may be associated with the synthesis by bacteria of simple organic substances on the medium with humic acids as a single source of carbon. 相似文献
14.
腐植酸和氮肥用量及其互作对植烟土壤质量的影响 总被引：3，自引：0，他引：3
以中烟100为材料,采用腐植酸和氮肥双因子盆栽试验,研究了腐植酸和氮肥用量及其互作对植烟土壤团聚体组成、养分及酶活性的影响。结果表明:干、湿筛法测定的土壤团聚体的平均重量直径均以T3处理(腐植酸900 mg/kg+氮肥40 mg/kg)最高,与其他处理相比提高幅度分别为15.3%~23.2%和6.5%~20.0%;方差分析显示,腐植酸与氮肥互作对土壤pH、有机质影响不显著,但对土壤碱解氮、有效磷、速效钾含量的影响达到极显著水平(P0.01);二者互作对烤烟各生育期土壤脲酶、蔗糖酶活性影响不同。由此,腐植酸和氮肥用量及其互作对提高土壤团聚体稳定性、土壤主要养分含量及酶活性具有显著效果。 相似文献
15.
Influence of humic acid on water retention and nutrient acquisition in simulated golf putting greens
Humic substances are frequently applied to creeping bentgrass ( Agrostis palustris Huds.) on golf putting greens to improve turf health and are marketed to enhance nutrient acquisition and possibly aid in retaining water in drought prone environments, but information on the role of humic substances in increasing soil water retention is limited. Additionally, it is difficult to separate the beneficial effects of nutrients and other ingredients added to commercial humic formulations from the effects of the pure humic substance. In our study, pure humic acid, tannic and citric acids were added to simulated creeping bentgrass putting greens. The organic acids were applied at normalized carbon rates of 250 mg C per litre by watering solutions through an automated irrigation system. Volumetric water content (VWC) and irrigation frequency, shoot and root growth, and tissue nutrient concentration of the turf were measured. None of the organic acid treatments improved water retention in the simulated greens. The humic acid-treated greens required more frequent irrigation than the untreated greens indicating that they were drying out more quickly. In addition, the addition of humic acid did not result in an increased tissue concentration of nutrients in the creeping bentgrass, top growth or dry shoot mass compared with the other treatments. However, creeping bentgrass root length was greater in the greens treated with humic acid compared with the untreated control. 相似文献
16.
Information is scant on the effect of humic acid (HA) on physiological, antioxidant and photosynthesis attributes of gerbera plants undergoing nutrient deficiency in culture solution. Gerbera plants cv. Malibu were grown in a factorial experiment based on a completely randomized design with 3 replications, using 3 different nutrient solutions [complete nutrient solution (NSc), 25% NSc (NS1), and 50% NSc (NS2)] treated with 2 levels of humic acid [0 (HA0) and 500 mg/l (HA1)].The interaction effect of HA and NS showed that HA improved the flower number in NSc, the transpiration in NS1+HA1, photosynthesis rate in NSc+HA1, stomatal conductance (gs) in NS2, mesophyll conductance of leaves in all NS levels and photosynthetic water use efficiency in NSc+HA1. The interaction effect of nutrient solution and HA on antioxidant activity was inconclusive, malondialdehyde content was the highest in NS2 and the lowest in NS1+HA1. The peroxidase activity increased in complete nutrient solution with and without HA and there were no differences among other treatments. Superoxide dismutase activity increased in NS1 and complete nutrient solution with HA and reached the highest in NSc. Humic acid was more effective in nutrient uptake, i.e., nitrogen, phosphorus, potassium, calcium, zinc, and iron (N, P, K, Ca, Zn, and Fe) in complete nutrient solution compared to NS1 and NS2. Conclusively, humic acid can compensate the nutrient deficiency stress of the culture solution in regards to protein synthesis, photosynthesis attributes regardless of the nutrient uptake of gerbera. 相似文献
17.
Studies were conducted during 2010–2012 at University of Horticulture & Forestry, Solan, Himachal Pradesh, India. Four fertigation levels were tested with humic acid (combined fertigation) and without humic acid (sole fertigation or fertigation alone). The experiment comprising eight treatment combinations in Randomized Block design, replicated four times. Investigations revealed that combined fertigation significantly increased plant height (5.7%), total dry matter (7.7%), leaf area index (3.2%), chlorophyll content (4.7%) and fruit yield (9.6%) over sole fertigation. Higher available N and K in was recorded in surface soils whereas, better translocation of available P was noted at 10–20 cm soil layers under combined fertigation. Higher nutrient recovery and fertilizer use efficiency was also noted in combined fertigation. Fertigation along with humic acid resulted in 20 per cent fertilizer savings over fertigation alone. It is concluded that efficiency of fertigation can further be increased by using humic substances in any agricultural production system. 相似文献
18.
Sand dunes are a typical landscape in the coast of western Taiwan, where Casuarina forests were established decades ago to stabilize sand dunes and protect the inland vegetation. Study of microbial biomass in such an ecosystem may give insights into the role of microbes in soil fertility and nutrient cycling. We established our study sites in two topographic units based on elevation and drainage types: upland and lowland. The study lasted for 2 years, and soil samples were collected every 3 months. Microbial biomass C (Cmic) and N (Nmic) were high in a shallow humic layer that rested on top of the soil (1222–1319 mg kg−1 for Cmic and 245–276 mg kg−1 for Nmic) and declined sharply to only one-tenth of the above values in the underlying surface soil (0–10 cm depth). Microbial biomass Cmic and Nmic in humic and surface soil were not significantly different between upland and lowland sites. In the upland soils, the mean Cmic was highest in autumn for both the humic and surface soil, and lowest in spring and summer for the humic layer and summer for the surface soil layer. In the lowland soils, the Cmic was highest in winter for both humic and surface soil, and lowest in spring and autumn for the humic layer and spring and summer for surface soil. Strong fluctuations of Cmic and Nmic were associated with the soil moisture prior to sampling, which appeared to control the size of microbial biomass in this environment. Temperature had little effect on the dynamics of soil microbial biomass in the sand dune forest ecosystem. 相似文献
19.
活化腐植酸–尿素施用对小麦–玉米轮作土壤氮肥利用率及其控制因素的影响 总被引：1，自引：0，他引：1
腐植酸-尿素是近年来的一种新型有机无机复合肥料,其增产效应显著,但是在小麦-玉米轮作中该肥料的利用率和环境调控因素尚不清楚。本研究通过田间定位与室内培养试验,以不施肥处理(Control)和单施尿素处理(Urea)为对照,研究腐植酸-尿素直接掺混处理(U+HA1)、腐植酸-尿素活化处理(U+HA2)和腐植酸-尿素活化催化处理(U+HA3)对小麦和玉米生长、土壤理化性质、氮肥利用率和土壤氮转化及土壤脲酶含量的影响。研究结果表明:活化腐植酸-尿素处理的小麦、玉米籽粒产量分别较Urea处理增产15%~28%和8%~10%。活化腐植酸-尿素施用显著地降低土壤容重、p H和土壤颗粒粒径的中位粒径,提高了土壤的比表面积、电导率、有机碳含量和矿质态氮含量。小麦季活化腐植酸-尿素处理下氮肥回收利用率较Urea处理显著增加,增加幅度为37%~91%,玉米季的增加幅度为78%~93%。活化腐植酸-尿素处理下小麦和玉米的氮肥农艺利用率和偏生产力均较Urea处理高。此外,回归分析表明活化腐植酸-尿素的氮肥当季回收利用率随土壤硝化比率、有机氮的矿化量及脲酶含量的增加而降低,而随土壤颗粒比表面积的增大而提高。本研究结果明确了腐植酸-尿素活化处理对小麦、玉米的增产效果较好,可改善土壤理化性质,其中腐植酸-尿素活化催化处理(U+HA3)的效果最好。研究结果为活化腐植酸-尿素肥料的深入研发与推广提供基础资料。 相似文献
20.
Zofia Sokolowska Mieczyslaw Hajnos Grzegorz Jozefaciuk Christian Hoffmann Manfred Renger 《植物养料与土壤学杂志》1997,160(2):327-331
Water vapor adsorption isotherms were measured for samples of kaolin and quartz amended with different amounts of humic acid extracted from a Cambic Arenosol under forest. Applying the approximation of the adsorption isotherms with the BET equation the monolayer capacities (surface areas) for the studied systems were calculated. For kaolin systems the surface area decreased sharply at low humic acid additions and this slowly increased with the further rise of the humic acid content, whereas for the quartz the increase of surface area was only noted for high humic acid contents. Using an exponential isotherm equation with a local BET model, the adsorption energy distribution functions were calculated for kaolin systems. The shape of the adsorption energy distributions showed that the increase in humic acid content changed the character of the surface from more hydrophilic to more hydrophobic. For intermediate humic acid contents, the energy distribution function had two maxima – more polar and less polar. At high humic acid contents the energy distribution function tended to the estimated value for pure humic acid, indicating high surface coverage with organic material. As measured by the mercury intrusion porosimetry, for the kaolin samples the amount of the largest pores decreases and the amount of the smallest pores increases with the accumulation of humic acid. For the quartz systems only very high doses of humic acid are reflected in changes of pore size distribution. 相似文献