0000000000520294
AUTHOR
Janis Krumins
showing 7 related works from this author
THE EVALUATION OF STABLE ISOTOPIC RATIOS 13C AND 15N IN HUMIC ACIDS ALONG A FEN PEAT PROFILE
2019
Mires are known as consistent environmental archives, but humic acids are the fraction of peat that is most recalcitrant and refractory to organic matter degradation, thus data on environmental changes during mire development can be recorded into them. This work was focused on the studies of stable isotopic ratios delta carbon-13 and delta nitrogen-15, and their distribution in humic acids within fen peat layers of different depths and peat composition. The variations in delta carbon-13 reflect isotopic variations in peat-forming plants over time and can be considered as a function of photosynthetic pathway that is being used to fix carbon dioxide. At the same time, variations in delta nitr…
Fen peat in environmentally friendly technologies
2018
Abstract Using peat as an energy source is currently incompatible with Environmental Policy Strategy of Latvia and 2030 Climate and Energy Package of European Union. The European Commission is looking at cost-efficient ways to make European economy more climate-friendly and less energy consuming. Although, fen peat alongside raised bog peat is categorized as fossil fuel, it is not traditionally used as fuel or growth substrate or for any other significant purposes in reasonable amounts. Large areas of fens are neglected where fen peat is slowly mineralizing and emitting greenhouse gases, such as carbon dioxide and methane, that are ones of the main triggers for the Climate Change. Thus, to …
Characterisation of humic acids in fen peat
2020
Fens store significant amounts of organic matter and thus are of high importance from the perspective of the organic carbon biogeochemical cycle. Fen peat comprises moderately to highly decomposed higher plant remains with relatively high mineral matter content. Humic acids form the major part of fen peat organic matter; they are also the most refractory and recalcitrant natural substances to degradation, and thus they contain essential information regarding mire and peat development over large periods of time as well as the organic carbon biogeochemical cycle. Moreover, humic substances in fen peat are a prospective resource for applications in agriculture and other sectors. The aim of thi…
Potential of Baltic Region Peat in High Added-value Products and Environmentally Friendly Applications - A Review
2021
The present review is dedicated to using of peat on the example of fen peat in high added-value products and applications. Mainly, but not limited, last decade literature was analysed from the perspective of innovation potential of peat applications in environmental technologies on examples of studies from the Baltic Sea region. Paper covers a wide range of applications of peat products started from agriculture to medicine and cosmetics. A separate chapter is devoted to the deep-processed peat product - humic substances (humate, humic and fulvic salts and acids). Generalised dependence of product extraction rate and its properties, depending on the process parameters are provided. Widely ar…
A study of weathered coal spectroscopic properties
2017
Abstract Current coal industry causes significant environmental pollution and the most air pollution deaths in the world, making the development of new eco-friendly applications one of the top priorities. Coal contains up to 50 % humic substances (HS), the majority of which is humic acid (HA). HA is well known for its beneficial properties and thus compounds extracted from coal can be used to develop new applications. To address this issue, we assessed structural composition of coal HS by measuring their spectroscopic properties. As the result, obtained spectra can be used to identify information about the molecules and thus allowing describing the composition of HS. The purpose of this stu…
Delineation of the boundary of an urban agglomeration: evidence from Riga, Latvia
2019
AbstractStatistical, morphological and functional approaches have long been used to delineate spatial boundaries of urban agglomerations. This research uses data from the Central Statistical Bureau and the State Revenue Service. The results indicate that morphological and functional approaches are essential when defining the agglomeration, however the outcomes are different. The most relevant consistency was observed in the territorial units adjoining the city of Riga due to the fact that they have a common labour market with Riga and share a strong functional linkage. However, the spatial extent based on the morphological approach confirms and highlights the effects of urban sprawl.
Humic Substances for Agricultural Applications: Properties and Challenges
2021
Nowadays, humic substances, the main organic components of soils and many fossil sediments, are becoming a material of wide application in agriculture and many technologies. Elemental, functional and spectral (UV, fluorescence, FTIR, 13C NMR spectra) analysis of industrially produced, as well as reference humic substances demonstrate significant differences in properties of humic substances depending on their origin, and thus, their potential application in agriculture. For authentication of humic substances’ origin, their elemental composition, as well as stable isotope (δC, δN, δO) ratios can be used.