Abstract

This study was carried out with a view to extract, quantify and characterize humic substances in Nigerian bitumen which desirable for soil fertility treatment. Bitumen samples were extracted from oil sands collected from four different locations: Agbabu, Mile 2, Olowo-Irele and Orisunbare in Ondo state, Nigeria. Extraction was done using Soxhlet extractor using toluene as extracting solvent. Varying concentrations of KOH solution were used and 3.5% of KOH was found to be the optimum concentration for the extraction of the humic substances. The gravimetric analysis showed 13.0, 6.3, 7.0, and 4.5% mean values of humic substances, extraction from Agbabu, Mile 2, Olowo-Irele, and Orisunbare respectively, while results of the humic acid determined by UV spectrophotometric method was 0.9, 0.7, 0.4 and 0.1% respectively. FTIR analysis results of the extracted humic substance samples showed peaks corresponding to the following functional groups: O–H, C–H, C=O, C=C, COO–, C–O, and C–O–C suggesting the presence of alcohol, carboxyl, phenol, carbonyl and esters which are present in the structure of humic and fulvic acids. The results of the elemental analysis revealed that humic substance extract was rich in the following elements (Na, Mg, Al, Si, P, S, K, Ca, Ti, V, Mn, Fe, Co, Ni, Cu, and Zn) which are needed for plants growth. Correlation and cluster analysis indicated strong and positive correlation among the detected elements, indicating similar sources or chemical affinity. The study concluded that the production of appreciable amount of humic substances, rich in minerals necessary for plant growth, from Nigerian bitumen is a possibility.

中文翻译：

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尼日利亚翁多州油砂沥青中腐殖质的经典分析与光谱分析

摘要

本研究旨在提取、量化和表征尼日利亚沥青中适合处理土壤肥力的腐殖质。从四个不同地点收集的油砂中提取沥青样品：尼日利亚翁多州的 Agbabu、Mile 2、Olowo-Irele 和 Orisunbare。使用索氏提取器进行提取，使用甲苯作为提取溶剂。使用了不同浓度的 KOH 溶液，发现 3.5% 的 KOH 是提取腐殖质的最佳浓度。重量分析表明，分别从 Agbabu、Mile 2、Olowo-Irele 和 Orisunbare 提取的腐殖酸的平均值为 13.0、6.3、7.0 和 4.5%，而紫外分光光度法测定的腐殖酸的结果为 0.9、0.7，分别为 0.4% 和 0.1%。提取的腐殖质样品的 FTIR 分析结果显示对应于以下官能团的峰：O–H、C–H、C=O、C=C、COO–、C–O 和 C–O–C，表明存在醇、羧基、苯酚、羰基和酯，它们存在于腐殖酸和富里酸的结构中。元素分析结果表明腐殖质提取物富含以下元素（Na、Mg、Al、Si、P、S、K、Ca、Ti、V、Mn、Fe、Co、Ni、Cu和Zn ) 是植物生长所必需的。相关性和聚类分析表明检测到的元素之间存在很强的正相关性，表明相似的来源或化学亲和力。该研究得出的结论是，从尼日利亚沥青中生产可观数量的腐殖质是可能的，这些腐殖质富含植物生长所需的矿物质。