Geochemistry of the Muthurajawela peat deposit of Sri Lanka

The Muthurajawela peat deposit of Sri Lanka has been studied for its geochemical distribution of 20 elements. There were no significant positive correlations of the metals with organic carbon. However, most metals, in particular Be, Zr, Li and the majority of the transition series metals, exhibit strong positive correlations with K, Al, Fe and Mn. Owing to the common occurrence of the latter elements in clay particles, this feature indicates the strong association of metals with the clay particles rather than with humic acids of the organic matter. The low pH of the peat bog presumably aids the conversion of the metals to ‘free’ ions which are in turn adsorbed on to clay particles. At low pH values the metal-organic complexes have low stability which accounts for the low metal-organic carbon correlations. However, due to the presence of marine-based sediments in the peat deposit, the metals could have been mobilized as chloro-complexes which were reduced to the free ion state by the effect of the humic acids. The general metal content of the peat deposit does not show enrichment compared to the average black shale, and the source of the metals is considered to be the laterites bordering the eastern part of the deposit and also the lagoonal sediments comprising the top and bottom horizons. Depth-element variations showed that the bottom horizon with abundant clay matter contains the highest amounts of the metals.     

Identification of peat and leonardite using humification parameters and Isoelectric focusing (IEF): A first approach

Several samples of peat and leonardite (organic fossil material of vegetable origin) and of humic extracts from peat and leonardite were characterized using some humification parameters and isoelectric focusing (IEF). The HA/TOC and the humification rate (HR) show values lower than 60% for peat and higher than 70% for leonardite samples. These two parameters are useful to distinguish peat from leonardite, but unable to identify the organic materials in the humic extracts. Peat an leonardite samples and their humic extracts were characterized using IEF and evaluating the quantitative distribution of the bands of the profile. The group of bands in the range from pH 4.8 to 5.5 (region C) is characteristics in all samples. In particular, the relative area is less than 55% for peat and humic extracts from peat and higher than 60% for leonardite and humic extracts from leonadite.     

Interaction of humic compounds with constant and variable valence metals in acidic solutions

The mechanism of the interaction of the humic substances (HSs) of peat and brown coal with the ions of constant (Zn and Pb) and variable valence (Cu, Cr, Co, and Ni) metals in acidic solutions (pH 2) was studied. It was established that the constant valence metals weakly interacted with HSs by an ion-exchange mechanism. However, the variable valence metal ions in an aqueous medium also interacted with the polyconjugation systems of HSs to create prerequisites for developing sorbents based on the HSs of caustobioliths for variable valence metals in acidic solutions.     

Changes in the composition of humic substances depending on the depth of peat occurrence

The fractional group composition of humic substances and the chemical structure of humic acids isolated from peats of different genesis from different depths of occurrence in peat deposits with the use of two extractants (0.1 N NaOH and 0.1 M Na₄P₂O₇ at pH 7) were studied. Peat from the upper aerated layer of the peat deposits contained more humic substances than peat from the deep layer, which occurred under anaerobic conditions, due to the pyrophosphate fraction of humic acids and fulvic acids. The humic acids of peat isolated from the deep layers of deposits had smaller molecular weights, and they were characterized by lower concentrations of carbohydrate and saturated hydrocarbon fragments and an increased contribution of aromatic polyconjugation systems, as compared with the humic acids of a surface layer.     

Bromination of humic acids of different origin

Data on the introduction of bromine atoms into the structure of humic acids isolated from the peat of Tver oblast and the brown coal of the Moscow Basin were generalized, and a comparative analysis of relevant methods was performed. It was shown that the test humic acids are similar in terms of structural parameters and demonstrate similar behaviors in the processes of bromination and hydrobromination. The dependences of the structural parameters of bromine-containing humic preparations on the mass fraction of bromine in them were obtained; correlations between the yields of humic preparations from the peat and the brown coal in the course of modifications were found; and the possible reaction paths of the bromination and hydrobromination processes were discussed. The biological activity of the bromine-containing humic preparations was tested, and its direct dependence on the mass fractions of bromine and phenolic hydroxyls in the humic preparations was found. It was shown that the modification of peat humic acids by hydrobromination is preferable for the production of biologically active humic preparations.     

The availability and binding of heavy metals in compost derived from household waste

Organic waste can be recycled as compost which has traditionally been used as a soil improver. As more waste is recycled as compost, it is becoming increasingly important to find alternative uses for compost. Leachability data are used to determine the environmental availability of Cd, Cu, Pb, and Zn contained in natural compost. Batch sorption data are used to determine uptake of additional Cd, Cu, Pb, and Zn by compost and assess its potential use in remediation work, as an alternative to natural materials such as peat. The relative binding of these additional metals to compost is found to be in the order Pb > Cd ≈ Cu > Zn. The sorption of metals on compost takes place, at least in part, by exchange of calcium bound to the compost and there is evidence that the sorption occurs in both humic and non‐humic sites in the compost. The use of compost to bind metals in remediation work is discussed. © 1999 Society of Chemical Industry     

改性泥炭腐植酸对戊唑醇的降毒作用

比较研究了天然的和改性的高位沼泽泥炭腐植酸的酸碱度,结果表明：经过机械活化后泥炭腐植酸酸度增加,腐植酸制剂中的烷烃羧基（CnCOOH）量增加,而芳香烃羧基（ArCOOH）基量减少。计算了离子化酸基的分离能量和分离程度,并研究了改性腐植酸制剂对于杀菌剂戊唑醇的降毒性能。     

Role of modified humic acids from peat in the detoxification of tebuconazole

The acid-base properties of the initial and modified humic acids from high-moor peat were studied. It was found that the acid properties of humic acid preparations increased for C _n COOH groups and weakened for ArCOOH groups upon the mechanical activation of peat. The energies of dissociation and the degrees of dissociation of ionogenic acid groups were calculated. The detoxifying properties of the modified humic acid preparations toward the fungicide tebuconazole were studied.     

Physicochemical properties of the humic substances of peat and brown coal

A comparison characteristic of the spectroscopic, viscous, and electrokinetic properties of the humic substances of peat and brown coal is given. Quantitative relationships between absorbance and the concentration of humic acids (HAs) were obtained. Methods for the determination of the amounts of humic substances in peat- and coal-alkaline reagents were proposed. The average molecular weights of the humic substances of peat and coal were determined by viscometry. A method was proposed for studying the electro-kinetic properties of humic substances of different nature. The dependence of electrophoretic mobility and kinetic potentials on the concentration and nature of HAs was determined. The electrophoretic mobility method can be used for rapid analysis to determine the concentrations of the functional groups of HAs.     

陕西某地泥炭腐植酸提取工艺的实验研究

本实验与陕西某地合作,就当地泥炭进行了分析,并在腐植酸的提取的实验研究中对腐植酸提取的传统工艺做了改进,采取先用NaOH水溶液浸泡泥炭,再在球磨机中进行水磨(同样的仪器干磨粒度只能到60～80目,而水磨可以到100～150目).再絮凝,提取时间缩短到了1 h(传统的方法需要1.5 h)<'[1] >,腐植酸的提取率提高...     

泥炭腐植酸类物质作为水煤浆分散剂的性能研究

通过将泥炭改性处理或分离分级腐植酸各组分,制备腐植酸类水煤浆添加剂,考察其对水煤浆的分散性能。结果表明,泥炭腐植酸类添加剂对煤浆有较好的分散性。不同类型泥炭腐植酸对煤浆的分散性不同,以低灰分、高腐植酸的草本泥炭最好,泥炭藓泥炭最差;腐植酸各级分受其分子量和官能团的影响,黑、棕腐植酸好于黄腐植酸;泥炭进行改性处理可增加腐植酸中的亲水和疏水基团,不同程度改善了对水煤浆的分散性能。     

Effect of the alkylation of brown coal and peat on the composition and properties of humic acids isolated from them

The effect of alkylation with alcohols in the presence of a mineral acid on the yield of humic acids from brown coal and peat was studied. A change in the ratio between the phenol and carboxyl groups of humic acids depending on the conditions of brown coal and peat alkylation was shown. An increased biological activity of humates obtained from the alkylated materials was noted.     

Chemical modification of humic acids by the introduction of indole-containing fragments

A method for the chemical modification of the initial structure of humic acids by acylation with indole-3-acetic acid chloride was developed to increase the biological activity of preparations based on peat and lignite humic acids. The plant growth stimulating effect and the antibacterial activity of the synthesized humic preparations were studied.     

颗粒腐植酸有机肥的生产试制

介绍了用含一定量棕黑腐植酸的风化煤和含一定量黄腐酸的草炭,生产具有一定颗粒强度的腐植酸有机肥的生产工艺流程和方法。     

泥炭吸附法去除废水中重金属

介绍了天然廉价矿物泥炭的物理化学性质,综述了泥炭的改性方法及其对多种重金属离子的吸附容量．分析了pH、改性方法、竞争离子浓度等因素的影响。并对泥炭吸附重金属离子的机理和规律进行了总结．其吸附机理有离子交换、络合、表面吸附、化学吸附等四种,吸附一般符合Langmuir吸附等温式或Freundlich吸附等温式。最后展望了泥炭在重金属废水处理中的应用前景,提出了一些建议。     

Comparison of five humic acids

The ultimate analyses, u.v-visible absorption spectra, fluorescence spectra and i.r. spectra of five humic acids have been studied. One was obtained commercially from peat, two from organic-rich soils, one from an estuary and one from a marine sediment. The u.v. spectra were used to compare average molecular weights which varied from 800 to 7000 and increased with the atomic $\text{H}\text{C}$ ratio. Fluorescence appeared to be due to poly-nuclear aromatic structures. All the humic acids showed maximum excitation at 360 nm and developed maximum emission in the range 430–455 nm but the humic acids from sediments showed an additional emission maximum at ~410 nm. Fluorescence from the peat humic acid was broad and secondary emission was observed with a maximum at 520 nm which was attributed to the formation of excimers. Fluorescence has been used to monitor the interaction of cations with humic acids in solutions of different ionic strengths which shows promise for distinguishing between metat—humate complex formation and the coagulation of a colloid. The structures of the humic acids are discussed in terms of the structures possessed by lignites.     

Differential thermogravimetry of peat fractions

Humic and fulvic acids were extracted from two peat samples designated H2 and H9 on the von Post index. The raw peat, humic acids, fulvic acids and remaining residues were tested using differential thermogravimetry in nitrogen and air. The results indicate peaks in the differential curves characteristic of each fraction. Both similarities and differences are observed; the fractions from the more decomposed H9 peat requiring higher temperatures for gasification and combustion. The results are consistent with general theories of peat formation.     

腐植物质钝化和活化土壤重金属的防污染作用

叙述了腐植酸与重金属作用的机理,即腐植酸通过络合、螯合、还原作用使重金属固定在土壤颗粒表面,从而影响它们的迁移并减少了重金属水溶态,降低其毒性。介绍了腐植酸在治理土壤重金属污染中的应用和相应的净化效果以及影响腐植酸吸附重金属的因素,如土壤类型、PH值、作用时间等,并指出腐植酸在降低土壤重金属活性（毒性）作用中存在的问题及发展趋势。     

Characterization of the Organic Matter of Humic Acids by Pyrolytic Gas Chromatography–Mass Spectrometry

The results of the pyrolytic analysis of products of the organic matter of Sphagnum fuscum, fuscum peat, and humic acids separated from peat with the use of pyrolysis–chromatography–mass spectrometry in the Rock-Eval version are presented. It was shown that Sphagnum fuscum and peat differed only slightly in the degrees of chemical transformation. Benzene, phenol, and their alkyl-substituted homologues predominated in the thermal desorption products of humic acids upon pyrolysis to 400°C. Acetic acid, monohydric phenols, syringol, and guaiacol, which are the basic compounds in the high-temperature fraction, were formed on the pyrolysis humic acids to 700°C from the carbohydrate, phenylpropionic, and guaiacylpropane structural fragments.     

使用草酸作为沉淀剂提高腐植酸品质

用有机溶剂对冷冻干燥的泥炭样品进行索氏提取和使用有机酸使腐植酸沉淀的两种纯化腐植酸的方法已经被探讨。用有机溶剂萃取,能够有效去除可溶性有机杂质（高达12％）,而对腐植质没有明显损失和改性。使用有机酸为沉淀剂是为了脱除腐植酸中的卤素和无机酸。本文比较了用上述方法获得腐植酸与用传统方法盐酸沉淀获得腐植酸。