The problem of municipal solid wastes' (MSW) utilization is one of the most actual all over the world nowadays. In Russia, landfills are still the main way for MSW utilization. However, waste ...decomposition, leading to landfill gas generation, causes, on the one hand, a lot of complaints from local people mainly due to hydrogen sulphide emissions. On the other hand, landfill gas, containing 40–60 vol % of methane, can be considered as calorific fuel. Solid oxide fuel cells (SOFCs), due to high operation temperatures, can be considered as an efficient device for landfill gas conversion to electricity and heat. Withal some companies and laboratories are developing SOFCs with direct methane oxidation to increase conversion efficiency on account of steam reformer expulsion. In this research, issues of landfill gas' useful utilization are considered. Experiments on different materials' application for model gas mixtures' direct conversion into energy by means of an SOFC and foreign experience in the field of landfill gas purification and estimation of its volumes in Russia are taken as initial data. The estimation results obtained allow the authors to consider SOFC application for landfill gas conversion as a significant market niche for Russian hydrogen technologies. Energy efficiency and environmental issues can also be improved by SOFC application in this niche.
Using a representative survey of German university students, we confirm that proclaimed support for environment protection policies depends on socio-cultural factors and political ideology. Unlike ...most related studies for other countries, we find that the environmental policy stance of German partisans does not follow the left-right cleavage. Only about 25% of the social-democratic partisans wholeheartedly support environment protection policies, whereas 50% of the green partisans, who, in Germany, also belong to the political left, do so; and when controlling for socio-cultural influences, social-democratic partisans become undistinguishable from Christian-conservative and market-oriented partisans. Focusing on behavioral influences, we find that some of the respondents' psychological traits are not filtered through their political ideology but directly influence their proclaimed attitudes towards environment protection policies. We identify as important behavioral determinants the locus of control and psychological traits that capture the respondents' susceptibility to making use of expressive rhetoric.
Quantity of waste toner cartridges has been generated following the increasing demand for printer and duplicator. Waste toner cartridge contains abundant valuable metals, plastics as well as toxic ...residual toner. Therefore, the recovery of waste toner cartridges is a meaningful subject, not only from waste treatment but also from environment protection. This study proposed a mechanical production line for recovering waste toner cartridges. The recovery process involved shearing process, magnetic separation, and eddy current separation. The recovery rates of steel (magnet), toner, aluminum, and plastic were 98.4%, 95%, 97.5%, and 98.8%, respectively. The results of the comparison between the production line and full manual dismantling indicated that the production line succeed in recovering waste toner cartridges. In addition, the proposed production line is an efficient and environmental friendly way for recovering waste toner cartridges.
This article presents the complex processing of low-grade and substandard chromium ores, as well as sludge tailings, with the production of composite chromium-containing materials and pigments, while ...improving environmental performance in the Republic of Kazakhstan through the utilization and processing of technogenic raw materials. In this work, to study the physicochemical properties of the starting materials, modern analytical, thermodynamic, chemical, granulometric, as well as computational, mathematical, laboratory, and experimental methods were used. In particular, studies of a method for producing composite pellets for chromite pigments based on industrial technogenic waste of the Republic of Kazakhstan are presented. Based on the results of the experimental studies, composite pellets were obtained, having a compressive strength of 150–220 kg/pellet and containing 49.7% of chromium oxide and 0.5–1.0% of carbon in its composition. The resulting chromite pigment based on the composite pellets is a modification of chromium oxohydroxide with the formula γ-CrOOH. The density of the resulting pigment is 3.4 kg/m3. The chromite pigment based on the composite pellets is recommended for use in various coloring compositions, including using it for printing on cotton and mixed fabrics intended for sewing outerwear.
Improved Low-Drag Pontoons for Water Bikes Nesteruk, Igor; Krile, Srećko; Möller, Thorsten
Journal of marine science and engineering,
09/2023, Letnik:
11, Številka:
9
Journal Article
Recenzirano
Odprti dostop
The popularity of modern water bikes increases due to the relatively high speed developed with the use of a human muscle power only. For example, the maximum speed of prototypes reaches the value 3 ...m/s. Similar vehicles can be used not only for recreation and fitness, but also for transportation. To increase their speed and tonnage, we recommend improving the pontoon shape and using electrical power. The underwater part of the pontoon shape was recommended to be similar to the body shape of the fastest fish in order to decrease the wave resistance and total drag. The optimal depth of the movement of corresponding shapes was calculated. The total drag and maximum speeds of the vehicles with the human muscle and electrical power are estimated. Expected success in improving the pontoon shape opens wide prospects for the use of these special-shaped hulls in shipbuilding.
The primary devices for extracting volatile components from dispersed materials in a vacuum are devices with the movement of raw materials by directed vibrations. During the analysis of the operation ...of such installations, some shortcomings were identified, due to the supply of heat flow to the processed raw material and the requirements for the choice of structural materials. In this article, the authors tested a heating method and a design of a sublimator with the supply of heat flow to the dispersed material by radiation from the heater. The sublimation zone is made in the form of a shaft formed by simple-shaped plates, the design and material of which involve the use of refractory and ceramic materials that are inert with respect to an aggressive vaporous sulfide medium. The movement of bulk material through the volume of the sublimator occurs due to rheological properties: sliding along inclined plates. Technological tests on the sublimation of arsenic sulfides from gravity and flotation composite concentrates of the Bakyrchik deposit (Kazakhstan) have shown the possibility of a high degree of sublimation of arsenic (more than 96–99%) while preserving precious metal composites in the sublimation residue and stable operation of equipment. Sublimation residues containing 0.14–0.30% As can be processed by known methods. The possibility of sufficiently complete removal of arsenic and its compounds from composite concentrates at a reduced pressure with the removal of the latter in the most environmentally friendly sulfide form has been established.
Proponents of development projects (e.g., new roads, mines, dams) are frequently required to assess and manage their impacts on threatened biodiversity. Here, we propose that the environmental ...legislation and standards that mandate such assessments are failing those threatened species and ecological communities listed as vulnerable. Using a case study of Australia's key environmental legislation, we highlight that vulnerable ecological communities receive no statutory protection, while vulnerable species are held to a less stringent standard in the impact assessment process compared with those that are endangered or critically endangered. In the 19 years since Australia's Environment Protection and Biodiversity Conservation Act 1999 was enacted, four times as many vulnerable species have declined in their threat status than have improved. Beyond Australia, we demonstrate the global relevance of this issue, as it applies to internationally recognized best practice impact assessment guidelines. These cases provide a cautionary tale: without greater attention and stricter assessment criteria in the impact assessment process, the vulnerable species of today risk becoming the endangered species of tomorrow, with all the attendant costs and missed opportunities for recovery that this implies.
Many countries around the world, including Russia, are performing extensive work towards meeting the Paris Agreement goals to reduce greenhouse gas emissions. One of the main industries that is an ...anthropogenic source of greenhouse gases is the coal-fired heat and power industry. A change-over from coal to natural gas becomes a promising measure for reducing carbon dioxide emission in the power industry. In the process, special attention is given to the combustion of natural gas mixed with hydrogen. This work examined engineering capabilities for burning hydrogen-containing gases (HCG) in conventional and condensing power facilities. Increasing the content of hydrogen in a mixture with natural gas when burning it in boilers has been demonstrated to affect the heat absorption of all heating surfaces in the boiler gas path, the gas temperature, and, ultimately, the boiler efficiency of the boiler, thereby requiring in-depth redesign of conventional gas-fired and pulverized coal-fired boilers. At the same time, the addition of hydrogen to natural gas extends the concentration range of stable combustion of such a mixture and increases the normal flame propagation velocity, which not only plays a positive role but also makes more intricate the practical implementation of the combustion of a hydrogen–natural gas mixture in burners and power facilities. Measures should be taken to prevent self-ignition of hydrogen-containing gases due to their higher fire and explosion hazard, including issues related to the location of process equipment and hydrogen transportation. A simultaneous decrease in atmospheric emissions of both water vapor and carbon dioxide during combustion of natural gas or hydrogen-containing gases in steam- and hot-water boilers can be attained by means of condensing heat recovery units that will improve the efficiency of fuel utilization and increase the thermal capacity of the power facility.
In this paper, we aim to better understand the factors that contribute to the substantive performance of EIA systems in low and middle income countries. Substantive performance is defined as the ...extent to which the EIA process contributes to the EIA objectives for the long term, namely environmental protection or, even more ambitious, sustainable development. We have therefore developed a conceptual model in which we focus on the key actors in the EIA system, the proponent and the EIA authority and their level of ownership as a key capacity to measure their performance, and we distinguish procedural performance and some contextual factors. This conceptual model is then verified and refined for the EIA phase and the EIA follow-up phase (permitting, monitoring and enforcement) by means of 12 case studies from Ghana (four cases) and Georgia (eight cases), both lower–middle income countries. We observe that in most cases the level of substantive performance increases during the EIA phase but drops during the EIA follow-up phase, and as a result only five out of 12 operational cases are in compliance with permit conditions or national environmental standards. We conclude, firstly that ownership of the proponent is the most important factor explaining the level of substantive performance; the higher the proponent's level of ownership the higher the level of substantive performance. The influence of the EIA authority on substantive performance is limited. Secondly, the influence of procedural performance on substantive performance seems less important than expected in the EIA phase but more important during the EIA follow-up phase.
In order to improve substantive performance we learned two lessons. Firstly, increasing the proponent's level of ownership seems obvious, but direct change is probably difficult. However, where international finance institutes are involved they can increase ownership. Despite the limited influence of the EIA authority, a proactive strategy of, for example, working together with international finance institutes has a slightly larger influence than a reactive strategy.
•Ownership of the proponent is the most important factor explaining the level of substantive performance.•The influence of the EIA authority on substantive performance is limited.•The influence of procedural performance on substantive performance seems less important than expected in the EIA phase but more important during the EIA follow-up phase.
Water supply (WS) tariffs have evolved significantly in the past decades, although in a varying fashion around the world. Indeed, this development is linked to increasingly demanding requirements, or ...objectives that have to be achieved by water utilities (e.g., stricter quality standards and infrastructure maintenance levels, cost recovery, social concerns and environmental protection demands). The perception of WS tariffs as a powerful management tool, subject to context dependent objectives, raises the concern on how utilities prioritize them. This hierarchy is desirable due to the possible conflicting nature of objectives. From that point of view, and on the basis of protecting the public interest, the fitness between objectives set by the utilities and actual needs may require a broader institutional approach. The need for regulatory activity may be required in the context of too much arbitrariness in tariff setting procedures. For this objective, a regulatory tool is set, based on multicriteria decision analysis (MCDA) modeling methods, to provide a requisite framework capable of considering the multiple dimensions of WS tariffs and the assessment of specialists, practitioners and other legitimate stakeholders in the ‘tariff setting’ decision making process. The specified tariff suitability framework (TSF) will work as a regulatory tool, taking into account the utilities’ particular context and background factors. The outcomes allow to determine the tariff suitability and to build tailored policy recommendations, which are critical aspects for a sound regulation.
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