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The issue of textile waste is a global concern, and Latvia, like many other countries, faces challenges related to the generation and management of textile waste. The textile industry is one of the largest contributors to environmental pollution, and the following points highlight the textile waste problem both in Latvia and on a global scale. Shredded textile waste, with its fibrous and porous composition, proves to be an excellent candidate for sound dampening materials. The irregular shapes and fine fibres inherent in shredded textiles create a structure that effectively absorbs sound waves, diminishing echoes and reducing overall noise levels. This inherent sound-absorbing property makes shredded textile waste an environmentally friendly alternative to traditional soundproofing materials. In addition to its acoustic benefits, the utilization of textile waste in sound dampening aligns with the principles of waste reduction and circular economy. The aim of this study is to develop a material with a good sound absorption capacity using textile waste. The textile used in the study was procured from a waste management firm located in North Vidzeme, Latvia. This company specializes in gathering uncontaminated textile waste from local residents. Shredding of textile waste was carried out using industrial shredding equipment. The particle size of the obtained textile fraction was 2X2 cm. Experiments with textile waste started in January 2024 in a laboratory. The created plates were tested for acoustic properties in the laboratory. The maximum sound absorption coefficient of the material obtained was 0.95 at a frequency of 4000 Hz. This is better than for synthetic mineral wool and slightly lower than for rock wool. [ABSTRACT FROM AUTHOR]

Air pollution is one of the most important environmental issues in the urban environment and causes health risks for citizens. The small particles PM 2.5 and PM10 consist of different trace elements. Industrial activities such as smelting, refining, and combustion processes are releasing significant amounts of metals into the air, leading to extensive air pollution. The aim of this study is to identify in which parts of Jelgava city the risks of air pollution caused by industry are the greatest. The snow samples were collected from 59 monitoring points in Jelgava and one in a rural area as reference. The snow samples were analysed using ICP MS for Al, Si, Cr, Mn, Fe, Ni, Cu, Zn, As, Mo, Cd, Ba, W, and Pb concentration analysis. The hierarchical cluster analysis of normalized chemical element concentrations was used to divide monitoring points into four groups with high, medium-high, medium, and low risks of industrial air pollution. The industrial air pollution risks are unevenly distributed in Jelgava. High and Medium high risks are indicated in residential areas. The trace element concentration distribution shows significant differences between industrial air pollution risk groups. Kruskal-Wallis test shows statistically significant differences between the clusters for all trace elements (p-value < 0.0001; alpha 0.05). The results show strong evidence of industrial air pollution in Jelgava city. Mostly in Jelgava city dominates low and medium risk of industrial air pollution, however, there are three points with high industrial air pollution risks. [ABSTRACT FROM AUTHOR]

Decomposition of solid waste in landfills causes global air pollution with methane, the most dangerous of the greenhouse gases. The emission potential of this gas is 28-36 times greater than that of CO2. With the help of methane-reducing Biocover, can find a solution to this problem. In this study, a biocover was developed in the laboratory to reduce methane emissions. When measuring the methane emissions of this biocover, data on the amount of carbon dioxide emissions were also obtained in parallel. The purpose of this study is to clarify the interaction between methane emission reduction and carbon dioxide emission flux. The laboratory experiment consisted of three parts. The first part was the creation of experimental tubes. Three experimental columns with a diameter of 160 mm and a height of 1500 mm were created. Active compost saturated with water at a thickness of 500 mm was used as a source of methane, a permeable layer of sand at a thickness of 300 mm was further formed and finally covered with biocover. Biocover represents 60% of fine-fraction waste, 20% of soil and 20% of compost. The second part was taking measurements. All measurements were performed with the Cavity Ring-Down Spectroscopy (CRDS) gas measurement device Picarro G2508. The third part was the analysis of the obtained data. The obtained data were analyzed by processing the data and obtaining the interaction between these gases. The experiment is planned to be continued by obtaining long-term emission data. This will help to develop more promising future approaches to reduce methane emissions from landfills. This research contributes to the understanding of sustainable environmental management practices and underscores the importance of a holistic approach to address multiple greenhouse gases simultaneously. [ABSTRACT FROM AUTHOR]

Nitrous oxide (N2O) is one of important greenhouse gas (GHG) whose main sources are agricultural soils. N2O forms in soil as a result of microbial processes, reinforced by the use of nitrogen-containing fertilizers. This study will look at how the formation of N2O in soil is affected by soil moisture and soil granulometric composition. Soil N2O isotopes of δ15Nα (central nitrogen position) and δ15Nβ (end nitrogen position) which could help to identify natural and anthropogenic sources of N2O emissions and the involvement of microorganisms in N2O production. N2O isotopes δ15NSP and δ15Nbulk can be traced or N2O produced by nitrification or denitrification. The study used total of 92 soil samples collected in 2020 and 2022. The study uses three types of agricultural soil with a different granulometric compositions. Soil from each agricultural plot was weighted into two samples, each of 1.5 kilograms to provide different humidity conditions - wet aerobic and wet anaerobic. The measurements were performed in a laboratory with the CRDS device Picarro G5131-i. The G5131-i analyzer measures nitrous oxide isotopes δ15N, δ15Nα, δ15Nβ, and δ18O with an accuracy of 0.7 ‰, and N2O concentration with an accuracy of <0.05 ppb (all measurements are averaged over 10 minutes). The data processing did not use all the data obtained from the Picarro G5131-i, but was selected by evaluating the changes in N2O concentrations when the concentrations had stabilized. In this research, three types of soil were used, from which it can be concluded that the type of soil, its inherent physical properties and reaction to the moisture regime play an important role in the formation of N2O isotopes. [ABSTRACT FROM AUTHOR]

It is generally estimated that gas, which generates more than half of the greenhouse gas (GHG) emission from waste industries in landfills, is seen as a serious environmental problem worldwide. It is therefore essential to promote management methods to reduce GHG emissions from landfills as well as other sources. One way of achieving this is the usage of different types of biocover applied to them. The aim of this study is to clarify the impact of the biocover created on GHG emissions. An experiment was conducted in laboratory conditions that studied the effectiveness of biocover developed in the laboratory. Three experimental columns with a diameter of 160 mm and a height of 1500 mm were created. Active compost saturated with water at a thickness of 500 mm was used as a source of methane, a permeable layer of sand at a thickness of 300 mm was further formed and finally covered with biocover. Biocover represented 60% of fine-fraction waste, 20% of soil and 20% of compost. The experiment was launched on June 6, 2022, and the first measurements were made two weeks later. All measurements were performed with the CRDS gas measurement device Picarro G2508 (Picarro Inc., USA California). All data analysis was carried out using Descriptive statistics methods. The largest reduction in emissions is projected directly for methane emissions, as biocover technology is appropriate to reduce methane emissions. Other GHG emissions are also expected to be reduced. NH3 emission measurements were also carried out to investigate the impact of the biocover on it. This experiment shows that the biocover created is effective and can be composed of material that has already been served. The experiment is intended to continue to obtain long-term data on the development of biotransformation and to develop more promising approaches in the future to reduce GHG emissions from landfills [ABSTRACT FROM AUTHOR]

Solid municipal waste landfills are the third largest source of man-made methane emissions. Methane is one of the greenhouse gases contributing to global warming. The capture of methane emissions in the waste sector is addressed by collecting it and using it for energy production. Methane emissions from active or closed landfills can be reduced by methane oxidation, which is developed as a covering over these landfills. It is usually composed of a gas distribution layer that favours micro-organisms that consume methane. The aim of this study is to find the most appropriate composition of the biocover in which filling material waste is used. In laboratory conditions, an experiment was conducted that studied the effectiveness of the biocover developed in the laboratory. Three experimental columns were created at a height of 160 mm and 1500 mm. A active compost saturated with water at a thickness of 500 mm was used as a source of methane, a permeable layer of sand at a thickness of 300 mm was further formed and finally covered with biocover. The biocover was composed of 60% of fine fraction waste, 20% soil and 20% compost, of the total volume. The experiment was created on 6 June 2022 and the first measurements were made two weeks later with CRDS equipment Picarro G2508. Measurements were made weekly for 4 months. The results of the study show that methane is released more forcefully after the first two months of application of the biocover. This is related to compost in the biocover, which has started to decompose actively, that methane oxidising micro-organisms develop on average after two months. [ABSTRACT FROM AUTHOR]

The oversupply of water during the floods and the low soil surface levels determine the difficult ecological, economic, and demographic conditions. It then leads to using agricultural land of different types and intensities and various methods of regulating the water regime: summer polders. Human activity has significantly impacted the ecological processes of the floodplains of the Svete floodplain with extensive amelioration works that have significantly altered the appearance of a natural park. The total area of the natural park Svete floodplain is 931 ha. The Valgunde summer one polder channel is the regulated tributary of the right coast of Lielupe and Mellupite, partly part of the nature park's Svete floodplain nature-barred area. During summer, the polder areas are flooded during high water levels of Lielupe. Still, during the summer, they must adjust the optimum humidity regime and ensure drainage systems, including drainage operation or to regulate the humidity regime in the floodplain, to preserve and restore the habitats of wetlands flood meadows and populations of native wild plants and animal species, also to ensure the use of agricultural land, reconstruction works have been carried out at the same time. The aim of this study is to assess the effects of rebuilding works on the hydrological regime of the Natura2000 site. In August 2021, 12 groundwater level monitoring points were established. At the monitoring point, 2 m deep pipes were installed in a 50 mm diameter, with a perforated lower part. Ejkelkamp Micro-Diver was inserted into the pipes, which records water levels every hour. Oneyear observation data were analyzed using descriptive statistics and Kruskal - Wallis. During the winter period, the polder flooded and drained systems for 65 days in the drained area and 156 days in the Natura2000 area. [ABSTRACT FROM AUTHOR]

Crop cultivation is beneficial for reducing soil erosion and nutrient loss, but there is conflicting information on how crop cultivation affects emissions of nitrogen dioxide (N2O), a potent greenhouse gas. Judicious selection of the cultivated crop in a plant succession is considered an effective approach to maintaining crop productivity. In this paper, we investigated the effects of cultivated crops on soil N2O emissions. Eight crops were used in this study: barley, buckwheat, clover, oats, potatoes, spring wheat, winter wheat and canola. Samples were collected in 32 experimental plots as well as a control plot. The samples are thus weighed in 3 l buckets, each 1.8 kg in total. Two samples were weighed from each plot to allow for different moisture regimes. Moistening is designed for wet aerobic and wet anaerobic soil conditions. Information on changes in soil weight after soil wetting was also collected. Measurements of N2O isotopes were performed using the Picarro G5131-i equipment in laboratory conditions. The obtained data were collected and analyzed. It was concluded that not all the obtained differences in N2O isotope data dispersion can be directly related to the cultivated crop, the physical properties of the soil, the use of fertilizers and the influence of the microorganism population cannot be excluded. The maximum value of d15NSP value is 18.58 and the minimum value is -53.41. On the other hand, the maximum value of d15Nbulk values is 26.76, and the minimum value is -56.97. In the conclusions, we get that both nitrification and denitrification dominate among cultures. [ABSTRACT FROM AUTHOR]

Agricultural activities account for about a third of greenhouse gas (GHG) emissions. Most of the GHG in the atmosphere are carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O). The aim of this study is to measure N2O isotopes in two differently managed agricultural soils. One soil is with organic farming and the other with conventional. Samples were collected in 32 experimental plots as well as a control plot. The samples are thus weighed in 3 l buckets, each 1.8 kg in total. Two samples were made from each plot so that they could have a different moisture regime. Moistening is designed for wet aerobic and wet anaerobic soil conditions. Information on changes in soil weight after soil wetting was also collected. Measurements for N2O isotopes were performed using a Picarro G5131-i instrument under laboratory conditions. The obtained data were collected and analysed. It was concluded that not all differences and interrelationships of the N2O isotope data obtained can be directly attributed to soil management. Differences between the effects of the microorganism population and the physical properties of the soil cannot be ruled out. The maximum value of δ15NSP value is 18.58 and the minimum value is -53.41. On the other hand, the maximum value of δ15Nbulk values is 26.76, and the minimum value is -56.97. In the conclusions, we get that both nitrification and denitrification dominate among cultures. [ABSTRACT FROM AUTHOR]