中國(guó)干旱半干旱草原地區(qū)土壤中腐殖質(zhì)的提取與表征研究
發(fā)布時(shí)間：2018-12-14 20:32
【摘要】：隨著氣候異常和人類非理性活動(dòng)的影響,我國(guó)干旱半干旱地域不斷擴(kuò)展,區(qū)域生態(tài)環(huán)境惡化,導(dǎo)致土地荒漠化、草場(chǎng)退化和土地污染等一系列問題加劇。土壤腐殖質(zhì)作為土壤微生物和植物生長(zhǎng)營(yíng)養(yǎng)物質(zhì)的主要承擔(dān)者,其含量和質(zhì)量直接決定著土壤品質(zhì)的優(yōu)劣。研究表明,土壤腐殖質(zhì)通過與土壤重金屬和有機(jī)污染物作用,參與其在土壤中的遷移歸宿,在土壤界面化學(xué)領(lǐng)域具有重要意義。為了解區(qū)域生態(tài)環(huán)境問題,本文選取干旱半干旱地域(內(nèi)蒙古-甘肅)土壤為研究對(duì)象,采用國(guó)際腐殖質(zhì)協(xié)會(huì)提供的標(biāo)準(zhǔn)方法對(duì)土壤有機(jī)質(zhì)進(jìn)行提取和純化,采用紫外/可見光譜、傅里葉紅外變換光譜和X-射線光電子能譜技術(shù)對(duì)提取的腐殖質(zhì)樣品進(jìn)行結(jié)構(gòu)表征,通過酸堿滴定實(shí)驗(yàn)對(duì)腐殖酸和富里酸表面酸性官能團(tuán)-COOH和Ar-OH進(jìn)行定量分析。實(shí)驗(yàn)結(jié)果表明:土壤腐殖質(zhì)含量受地域干燥指數(shù)的影響,隨區(qū)域內(nèi)干燥指數(shù)AI(年平均降水量/蒸發(fā)量)的增大,土壤中可提取腐殖質(zhì)的含量增大,當(dāng)干燥指數(shù)低至0.05時(shí),實(shí)驗(yàn)所采取的提取方法無(wú)法將土壤中少量的腐殖質(zhì)提取出來(lái)。紫外/可見吸收光譜E4/E6和E2/E3比值隨干燥指數(shù)的變化表明,對(duì)于腐殖酸分子,干燥指數(shù)對(duì)分子量和芳香度的影響存在一個(gè)閾值,即干燥指數(shù)為0.53,干燥指數(shù)在由0.17增至0.53,腐殖酸相對(duì)分子質(zhì)量和芳香性逐進(jìn)增強(qiáng),當(dāng)干燥指數(shù)超過0.53時(shí),腐殖質(zhì)分子芳香度和分子量降低。而對(duì)于富里酸分子,分子量和芳香度隨干燥指數(shù)的變化呈無(wú)規(guī)律腐殖酸和富里酸表面元素主要為碳、氮、氧(除氫以外),表面氮含量約占3.32-5.79%,碳含量為62.98-71.08%,氧含量為25.68-35.38%。腐殖酸表面含氧量和(O+N)/C值均隨干燥指數(shù)上升而增加;而富里酸表面含氧量和(O+N)/C隨干燥指數(shù)的變化存在一臨界干燥值(AI=0.32),臨界干燥值范圍內(nèi),樣品極性和氧含量隨區(qū)域干燥指數(shù)成正比,干燥指數(shù)超過0.32,富里酸樣品極性和氧含量隨區(qū)域干燥指數(shù)增加而降低。碳在腐殖質(zhì)中的7種化學(xué)形態(tài)和結(jié)合能分別為:芳香碳C/C-H(282.5e V)、烷基碳C/C-H(283e V)、C(O)O(283.5e V)、O(284.4e V)、C=O(285.6e V)、C(O)N(286.45e V)、C(O)O(287.1e V);氮在土壤腐殖質(zhì)中的三種化學(xué)形態(tài)和結(jié)合能為:NH2(397.8 e V)、NR3+(399.1e V)和NO2(400.5e V);氧在土壤中的化學(xué)形態(tài)和結(jié)合能為:C=O(529.5e V)和C-O(530.5e V)。研究區(qū)域內(nèi),腐殖酸分子中羧基的含量在3.24-4.79mmol/g,酚羥基的含量約在0.16-0.34 mmol/g;富里酸分子中羧基的含量在5.96-10.66mmol/g,酚羥基的含量約為0.12-5.44mmol/g,同一樣品中富里酸分子的羧基官能團(tuán)含量高于腐殖酸物質(zhì)。腐殖酸和富里酸分子羧基和酚羥基含量的變化與地域干燥指數(shù)無(wú)關(guān)。
[Abstract]:With the influence of abnormal climate and irrational human activities, the arid and semi-arid areas in China are expanding and the regional ecological environment is deteriorating, which leads to a series of problems, such as land desertification, grassland degradation and land pollution, etc. Soil humus, as the main carrier of soil microorganism and plant growth nutrients, its content and quality directly determine the quality of soil. The results showed that soil humus participated in the migration of soil through its interaction with heavy metals and organic pollutants, which was of great significance in the field of soil interface chemistry. In order to understand the problem of regional ecological environment, the soil in arid and semi-arid region (Inner Mongolia and Gansu) was selected as the research object, and the soil organic matter was extracted and purified by the standard method provided by the International Humus Association. The structure of the extracted humus was characterized by UV / vis, Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). The surface acidic functional groups of humic acid and fulvic acid-COOH and Ar-OH were quantitatively analyzed by acid-base titration. The results showed that the content of soil humus was affected by regional drying index. With the increase of AI (annual average precipitation / evaporation), the content of extractable humus in soil increased, and when the drying index was lower than 0. 05, the content of extractable humus in soil increased. The method used in the experiment could not extract a small amount of humus from the soil. The ratio of E4/E6 and E2/E3 in UV-Vis absorption spectra varies with drying index, which indicates that there is a threshold for the effect of drying index on molecular weight and aromaticity of humic acid molecules, that is, the drying index is 0.53. When the drying index was increased from 0.17 to 0.53, the relative molecular weight and aromaticity of humic acid increased gradually. When the drying index was higher than 0.53, the aromatic degree and molecular weight of humus molecule decreased. For fulvic acid molecules, the surface elements of humic acid and fulvic acid are mainly carbon, nitrogen, oxygen (except hydrogen), and the content of surface nitrogen is about 3.32-5.79g, and the change of molecular weight and aromaticity with drying index is irregular, and the surface elements of humic acid and fulvic acid are mainly carbon, nitrogen and oxygen (except hydrogen). The carbon content was 62.98-71.08 and the oxygen content was 25.68-35.38. The surface oxygen content and (O N) / C value of humic acid increased with the increase of drying index. In the range of critical drying value, the polarity and oxygen content of the sample are proportional to the drying index, and the drying index is more than 0.32, while the oxygen content and oxygen content on the surface of fulvic acid have a critical drying value (AI=0.32). The polarity and oxygen content of fulvic acid samples decreased with the increase of regional drying index. The seven chemical forms and binding energies of carbon in humus are: aromatic carbon C/C-H (282.5e V), alkyl carbon C/C-H (283e V), C (O) O (283.5e V), O (284.4e V), Con O) (285.6e V),) C (O) N (286.45e V), C (O) O (287.1e V); The three chemical forms and binding energies of nitrogen in soil humus are NH2 (397.8 e V), NR3 (399.1 EV) and NO2 (400.5 e V);). The chemical forms and binding energies of oxygen in soil are Cno (529.5e V) and C-O (530.5e V). The contents of carboxyl and phenolic hydroxyl groups in humic acid molecules were 3.24-4.79 mmol / g and 0.16-0.34 mmol/g;, respectively. The content of carboxyl group in fulvic acid molecule is 5.96-10.66 mmol / g, and the content of phenolic hydroxyl is 0.12-5.44 mmol / g. The carboxyl group content of fulvic acid molecule in the same sample is higher than that of humic acid. The changes of carboxyl and phenolic hydroxyl groups of humic acid and fulvic acid were not related to the regional drying index.
【學(xué)位授予單位】：哈爾濱工業(yè)大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：S153.622
本文編號(hào)：2379273
[Abstract]:With the influence of abnormal climate and irrational human activities, the arid and semi-arid areas in China are expanding and the regional ecological environment is deteriorating, which leads to a series of problems, such as land desertification, grassland degradation and land pollution, etc. Soil humus, as the main carrier of soil microorganism and plant growth nutrients, its content and quality directly determine the quality of soil. The results showed that soil humus participated in the migration of soil through its interaction with heavy metals and organic pollutants, which was of great significance in the field of soil interface chemistry. In order to understand the problem of regional ecological environment, the soil in arid and semi-arid region (Inner Mongolia and Gansu) was selected as the research object, and the soil organic matter was extracted and purified by the standard method provided by the International Humus Association. The structure of the extracted humus was characterized by UV / vis, Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). The surface acidic functional groups of humic acid and fulvic acid-COOH and Ar-OH were quantitatively analyzed by acid-base titration. The results showed that the content of soil humus was affected by regional drying index. With the increase of AI (annual average precipitation / evaporation), the content of extractable humus in soil increased, and when the drying index was lower than 0. 05, the content of extractable humus in soil increased. The method used in the experiment could not extract a small amount of humus from the soil. The ratio of E4/E6 and E2/E3 in UV-Vis absorption spectra varies with drying index, which indicates that there is a threshold for the effect of drying index on molecular weight and aromaticity of humic acid molecules, that is, the drying index is 0.53. When the drying index was increased from 0.17 to 0.53, the relative molecular weight and aromaticity of humic acid increased gradually. When the drying index was higher than 0.53, the aromatic degree and molecular weight of humus molecule decreased. For fulvic acid molecules, the surface elements of humic acid and fulvic acid are mainly carbon, nitrogen, oxygen (except hydrogen), and the content of surface nitrogen is about 3.32-5.79g, and the change of molecular weight and aromaticity with drying index is irregular, and the surface elements of humic acid and fulvic acid are mainly carbon, nitrogen and oxygen (except hydrogen). The carbon content was 62.98-71.08 and the oxygen content was 25.68-35.38. The surface oxygen content and (O N) / C value of humic acid increased with the increase of drying index. In the range of critical drying value, the polarity and oxygen content of the sample are proportional to the drying index, and the drying index is more than 0.32, while the oxygen content and oxygen content on the surface of fulvic acid have a critical drying value (AI=0.32). The polarity and oxygen content of fulvic acid samples decreased with the increase of regional drying index. The seven chemical forms and binding energies of carbon in humus are: aromatic carbon C/C-H (282.5e V), alkyl carbon C/C-H (283e V), C (O) O (283.5e V), O (284.4e V), Con O) (285.6e V),) C (O) N (286.45e V), C (O) O (287.1e V); The three chemical forms and binding energies of nitrogen in soil humus are NH2 (397.8 e V), NR3 (399.1 EV) and NO2 (400.5 e V);). The chemical forms and binding energies of oxygen in soil are Cno (529.5e V) and C-O (530.5e V). The contents of carboxyl and phenolic hydroxyl groups in humic acid molecules were 3.24-4.79 mmol / g and 0.16-0.34 mmol/g;, respectively. The content of carboxyl group in fulvic acid molecule is 5.96-10.66 mmol / g, and the content of phenolic hydroxyl is 0.12-5.44 mmol / g. The carboxyl group content of fulvic acid molecule in the same sample is higher than that of humic acid. The changes of carboxyl and phenolic hydroxyl groups of humic acid and fulvic acid were not related to the regional drying index.
【學(xué)位授予單位】：哈爾濱工業(yè)大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：S153.622
【參考文獻(xiàn)】
相關(guān)碩士學(xué)位論文 前1條
1 曲風(fēng)臣;土壤腐殖酸分級(jí)、表征及其光化學(xué)作用研究[D];大連理工大學(xué);2006年
，本文編號(hào)：2379273
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