Rainer Schiene

Agricultural reclamation of disturbed soils in a lignite mining area using municipal and coal wastes: the humus situation at the beginning of reclamation

Soils disturbed by long-term opencast mining were treated with organic waste materials for reclamation. Humic substances were extracted from waste and soil samples and analysed using pyrolysis-gas chromatography/mass spectrometry and electrofocusing. Furthermore, analytical pyrolysis permits to study all starting materials in situ. According to structural similarities, the statistical evaluation of the pyrolysis results clearly indicates three sample groups. The first group, called compost, implies the waste materials compost and composted sewage sludge. Moreover, pyrolysis revealed that coal humic substances are predominant in brown coal sludge, pure mine soils and mine soils treated with the different organic waste materials. They constitute the second group. The sewage sludge contains a high nitrogen potential, as expected, and represents the third group. Finally, pyrolysis generally showed the specific structural characteristics of humic and fulvic acids, respectively. Electrofocusing yielded for all samples a signal pattern that is typical of humic substances. However, number and ratio of the signals differ according to the special structural features of the samples.

Nitrogenous Fertilizers from Lignins — A Review

The desire to apply and utilize lignin as a plant nutrient is prompted by two aspects. The first one is the chemical relationship between lignin and humus. The lignin component of plants is a basic chemical substance for the formation of soil organic matter (SOM). Humic substances are required for the soils to become fertile. At the same time they essentially influence the structure and the biological activity of the soils. The second aspect is the availability of great quantities of technical lignin, a by-product in the chemical processes of wood utilization. Nowadays, this happens almost exclusively in chemical pulp manufacture. However, the hydrolysis lignin from the processes of wood hydrolysis is also noteworthy from the historical point of view. Over the past few decades, chemical pulp manufacture has increased on a global scale, and so has the amount of byproduct lignin. In the modern industrial methods of chemical pulping technical lignins are used as a valuable fuel and they are also incorporated into the pulping chemical recovery system. Efforts made for their more effective material utilization, however, continue to be significant, in particular because of the fact that lignin is a sustainable, renewable material.

Structural characterization of an Organosolv lignin by analytical pyrolysis and wet chemical degradation methods

Abstract New sulphur-free lignins of an Organosolv pulping and a spruce milled wood lignin as reference sample were structurally characterized using pyrolysis-gas chromatography/mass spectrometry. The principal component analysis of the pyrolysis results clearly indicates that, in comparison with the milled wood lignin, the structure of the Organosolv lignins is strongly changed. Furthermore, the pulping parameters, temperature, time, methanol content, and process design, as well as the pH value of the precipitation from the spent liquor, influence the structural features of an Organosolv lignin differently. When including in the statistical interpretations essential results of wet chemical methods, relationships between lignin-typical bonds, diphenylmethane units, phenolic and aliphatic hydroxyl groups and the pyrolysis pattern can be identified. A regression equation is discussed, which makes it possible to determine diphenylmethane structures on the basis of the results obtained from pyrolysis.

Kennwerte und Eigenschaften der auf Braunkohlenbasis durch oxidative Ammonolyse hergestellten Humusdüngestoffe

Der auf Braunkohlenbasis durch oxidative Ammonolyse hergestellte Humusdüngestoff wird anhand seiner Standardparameter, Elementgehalte und chemischen Eigenschaften beschrieben. Hiernach ist die N-modifizierte Braunkohle ein schadstoffarmes, N-reiches, dauerhumusähnliches Bodenverbesserungsmittel, das als Granulat sehr lagerungsbeständig ist. Der neue Humusdüngestoff enthält stabil 5,78 ± 0,38% Gesamtstickstoff, der chemisch unterschiedlich gebunden ist. Aufgrund seiner vergleichsweise geringen Nmin-Gehalte kann er in größeren Mengen zur nachhaltigen Verbesserung der KAKpot und Nt-Bodenvorräte humusfreier und kolloidarmer Kippenböden eingesetzt werden.

Freilandversuche zur eignung chemisch veränderter weichbraunkohle als bodenverbesserungsmittel bei der landwirtschaftlichen rekultivierung humusfreier kippenböden 1 : Field experiments with n-modified brown coal as humus fertilizer in agricultural revitalisation of humus free dump soils

Die bodenmeliorativen und ertragssteigernden Effekte des Einsatzes von N-modifizierter Weichbraunkohle als Humusdüngestoff bei der landwirtschaftlichen Rekultivierung humusfreier Kippenböden werden in mehreren Freilandversuchen überprüft. In diesem Beitrag wird über die zu Rekultivierungsbeginn mit W.-Roggen, W.-Weizen, Kartoffeln und Luzerne erzielten Ergebnisse berichtet.

Fertilizing effects of N-modified brown coal and its consequences to plant, soil and N-leaching losses

The amount of mineral fertilizer (urea) which is equivalent to the effective nitrogen content of a distinct amount of N-modified brown coal was determined in pot and lysimeter (lab-scale suction lysimeters) tests. Furthermore, the effects of varying amounts of N-modified brown coal on nitrogen leaching have been investigated for different dump substrates (pure sands, loamy sands). Soil and plant investigations complement the test programme. They give first information about the effects of N-modified brown coal applications on agricultural and horticultural measures and underline its value as soil amendment.