The Scientific Journal of Riga Technical University
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Application of Citeromyces Siamensis for Molasses Wastewater Decolorization
Full text linkMolasses is a brownish black viscous liquid produced in the last step of the cane sugar separating process. Molasses can be used in many industries, such as fertilizer production, animal husbandry, alcohol production, monosodium glutamate production, and acetic acid making. In Thailand, it is mainly used to produce alcohol and as animal feed. Molasses waste water is high in biochemical and chemical oxygen demand and suspended solids. If released into the environment without treatment, it will cause many environmental problems. Moreover, the molasses wastewater contains melanodin that is difficult to remove, which gives it a dark colour. The treated water, therefore, has a dark colour. If the treated water is released into a natural water source, it will cause the water to have an unusually dark colour. This research aims to study the optimum conditions for using Citeromyces siamensis microorganisms for biological disposal of wastewater. The experiment was conducted to find conditions that promote the reduction of the colour of molasses in wastewater. It has been found that the addition of 1 % glucose and 1 % peptone is more effective in decolourization by Citeromyces siamensis than the addition of other nutrients
Treatment of Textile Wastewater Containing Dyes
Full text linkIn recent years there has been an interest in the study of new methods for the removal of textile dyes from water due to its large-scale use in different industries. For example, paper printing, textile, leather, pharmaceutical, food or technological applications. It is estimated that more than 700 thousand tons of about 10 000 different types of dyes are produced annually. Most of them are of synthetic origin and can generate adverse effects, for example, teratogenic, mutagenic and carcinogenic action. Dyes are mainly applied in the textile industry, and they are usually classified into anionic (acid dyes), cationic (basic dyes) and non-ionic (disperse dyes) dyes. The direct discharge of dyes into the environment can cause various damages to plants and animals: dyes can block the penetration of sunlight, reduce the photosynthetic efficiency of aquatic plants and ultimately destroy the ecological balance of the aquatic ecosystem. This study determines the adsorption efficiency of congo red, methylene blue, rhodamine B and naphthol green B dyes used in textile industry by using the aerogel. To achieve the aim, the effects of adsorbent dosage, pH, dyes concentration, adsorption contact time and temperature of solutions were studied. Kinetic data, equilibrium isotherms and thermodynamic parameters were determined
Review on Sustainable Cryopreservation and Nonfreezing Storage Solutions of European Honeybee Apis Mellifera Drone Semen
Full text linkThe European honeybee Apis mellifera is the main pollinator for most crops used for human consumption. However, a number of diseases, parasites, pesticides and other factors that generally result in the widely described colony collapse disorder weakens honeybee colonies. In order to maintain the existing honeybee germ lines and facilitate the creation of new disease-resistant lines, it is necessary to ensure consistent breeding work, which would also allow the long-term preservation of the unique germplasm lines. One of the most promising solutions for the preservation of honeybee germplasm is the storage of honeybee drone semen. In recent decades, there has been a renewed interest in the preservation of honeybee drone semen using both cryopreservation and non-freezing storage methods. This review looks at the latest developments in novel sperm storage technologies and compares them to well-known preservation solutions. Additionally, the most accessible and widely used solutions will be reviewed, taking into account the cost of the necessary equipment, the complexity of the methods, time consumption and resulting sperm quality
Comparison of Most Popular Buildings Performance Simulation Tools
Full text linkA critical procedure in sustainable building design is the building energy performance assessment, which has significant implications for global energy consumption and climate change. This study compares three simulation software programs for a photovoltaic system on a building’s roof. The low-rise residential buildings in three East Mediterranean cities (Amman, Mafraq, and Aqaba) represent moderate drywarm, semiarid, and humid subtropical climate zones were compared using three simulation software programs (IES-VE, DesignBuilder, REVIT) for a typical building with PV on the roof and the second scenario without a PV system installed on the roof. This investigation aims to evaluate the shading effect of the PV system on a building’s roof structure by calculating the total electrical load required to maintain thermal comfort inside the building. The final results showed significant discrepancies between the three software for the base building design and the PV system on the roof, with a range of around 50 %. This highlights the importance of evaluating and calibrating different simulation tools and using them with a great deal of caution
How to Measure Public Awareness of Environmental Protection
Full text linkHuman actions intensified processes in the environment, such as climate change, loss of biodiversity and environmental pollution, escalating the role of environmental awareness. Along with the formal environmental education performed in pre-schools, schools and universities, vocational education is taking a special role due to the flexibility of educational formats as well as the diversity and deepness of topics to be covered. While there are a lot of public awareness campaigns on climate change, environmental and nature protection issues, there is still a lack of methods on how to measure the effectiveness of these. Within the present paper, the methodology for measuring the effectiveness of outdoor events focused on awareness raising of local society on nature protection actions. The methodological framework is based on the ecosystems services travel cost method – estimation of the value of nature provided benefits generated by ecosystems. As a case study object to adapt the methodology, a project named Nature Concert Hall is selected. Nature Concert Hall is a symbiosis of science, music, poetry and visual art organising annual summer festivals (1–2 per year) in previously unrecognized natural settings, such as meadow, forest, seacoast or riverside but dedicated to a specific nature protection topic. The effectiveness of the event is measured for the period of 7 years
Optimizing Beekeeping Production through System Dynamics Modeling: A Case Study on Forecasting Bee Queen Rearing Capacity
Full text linkCommercial bee queen rearing is an intensive process in which the main commercial product, bee queens, are produced in a short period of time. The intensity is even more severe in regions where the beekeeping season is shorter, as preparation, rearing initiation and capacity increase during the season consume a lot of time. Bee queens can be divided into different product categories: virgin, mated, mated in isolated station, and instrumentally inseminated queens, and they can be further divided by race, pedigree, and colony characteristics. Each category is with varying time and resource consumption. To optimize bee queen rearing and choose the appropriate rearing strategy, product categories, production capacity dynamics, and other aspects, the authors of this case study developed a system dynamics model with the aim of finding the optimal number of production units, the most appropriate product groups and their volumes, according to changes in income and time consumption. The model clearly shows the system’s sensitivity to having too many production units – nuclei and queen rearing colonies. Too many production units led to ineffective use of nuclei, increased bee queen mortality, high bee queen surplus, high human and time resource costs and unnecessary batching of orders. The developed model demonstrated how to predict the optimal production capacity and how inefficiency leads to the inevitable collapse of the bee queen rearing system, from which the bee queen breeder cannot recover during the season. The model allowed to conclude that balancing material and human resources in bee queen rearing is very important for efficient production
Do Non-Formal and Informal Education Impact Reaching the Bioeconomy and Green Deal Goals?
Full text linkTo achieve the goals of the bioeconomy, formal education is a cornerstone, as well as non-formal or lifelong learning and informal education. Professionals in their specific profession can expand their knowledge in the context of bioeconomy in non-formal education by attending various seminars and courses, acquiring knowledge in informal or self-education, and reading books, internet sources and other resources. Competencies in the bioeconomy are a cross-cutting element for a professional working in any field. RTU IESE is a leading institution providing non-formal and informal education in bioeconomy and Green Deal topics. This study aims to identify the potential of non-formal and informal education in achieving the goal of bioeconomy and the Green Deal. Non-formal and informal education is an essential type of education that can increase bioeconomy competencies for professionals. Seminars, conferences, courses, lectures, and workshops are non-formal education tools, but with informal – everyday learning (books, scientific papers, conversations, internet resources, TV, audio materials) it can be accelerated to reach bioeconomy and Green Deal goals faster
GHG Savings Calculation: Switch from Electricity Production to Biomethane. Case Study
Full text linkCarbon dioxide is one of the main components of greenhouse gases. The amount of anthropogenic CO2 emissions in the atmosphere reached 37.9 Gt, which is 60 % more than in 1990. The use of CO2 in the production of valuable products can help to reduce the amount of CO2 in the atmosphere. Biomethane fuel production could be a successful solution in Latvia as well. The work includes a case study of a Latvian biogas production facility Agro Iecava with a switch from biogas to biomethane production. All calculations are made according to REDcert rules. For biofuel production the Plant uses 13 types of substrates, which is also reflected in the calculation. The work shows a step-by-step algorithm for research and analysis. The experience can be used at other biogas production stations, regardless of its location. The analysis of the Plant shows that switching to biomethane production saves up to 80.34 % of GHG emissions (with an estimated loss during transportation in the network of 1 %). In the worst-case scenario, this amount is 76.34 % (loss from transportation is 5 %), which is also above the minimum indicated in the Renewable Energy Directive
Carbon Neutrality in Municipalities: Balancing Local and Centralized Renewable Energy Solutions
Full text linkCarbon-neutrality in municipalities can be achieved by combining individual heating (IH) and district heating (DH) solutions involving the use of renewable energy sources (RES). Each approach has advantages and disadvantages, but the best solution depends on the specific circumstances of each municipality. As an environmentally friendly and efficient energy use, a decentralised heat supply contributes to achieving energy conservation and emissions reduction goals. Decentralised energy use, such as solar collectors with an accumulation system or biomass as a resource, reduces dependence on centralised heat generation and transmission. Often, the appropriate infrastructure for connection to DH networks has not yet been built. On the other hand, it is easier to make investments to construct proper infrastructure in the case of large-scale centralised heat supply. Moreover, a centralised heat supply with RES can provide more inhabitants with RES heat energy. Within the framework of the study, the possibilities of using renewable energy sources in one of the municipalities of Latvia – the Carnikava parish of Ādaži Municipality – are analysed. The study examines two scenario complexes including IH solutions in buildings or DH solutions with a centralised approach. The study evaluates several alternatives to increase the share of RES (e.g., solar collectors, biomass, heat pumps, etc.) in the centralised heat supply. To evaluate RES individual solutions in various municipal buildings, the study evaluates alternatives with different technical solutions that increase the use of RES in heat supply
Analysis of Textile Circularity Potential
Full text linkGlobal annual textile consumption has doubled in the last two decades and is expected to keep increasing [1]. Since the textile system operates primarily in a linear way, it is highly polluting and creates a lot of waste. But nevertheless, it has a high potential for circularity since most textile products can be recycled or reused. Today most of the waste ends up in landfills, and less than 1% is recycled back into textiles [2]. This study aims to gather information and evaluate which textile product group has the highest potential for circular economy growth. It covers three main textile product streams: fashion, home, and technical textiles. The groups were compared using eleven criteria: environmental impact, washes, market demand, technology energy efficiency, social aspect, production, export/import, landfilled waste, recycled waste, synthetic materials, projected lifetime. Indicative values have been found for each sustainability indicator by using and mathematically transforming data from the scientific literature. The evaluation method used in this study was multi-criteria decision analysis. The results indicated that the fashion textile group has the most significant potential for circular economy development