• Journal of the Korean Applied Science and Technology
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• v.27 no.3
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• pp.318-324
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• 2010

In this study, commercial pellet type sorbents for the collection of $CO_2$ from a local municipal waste incinerator were prepared and characterized in terms of adsorption efficiency by varying the operating conditions of a field process. The concentration of $CO_2$ in the flue gas ranged from 8 to 10%, which entered the test packed bed. As a result of this experiment, the sorbent procured from A-company, which is mainly composed of calcium compounds, showed the highest adsorption efficiency. The regeneration efficiency was fairly low, however. It also was found that based on adsorption breakthrough time, the relatively low flow rate of 10 LPM into the bed allowed higher collection efficiency. The higher flow rate of 40 LPM, on the other hand, tended to decrease the retention of the adsorption.

• Applied Chemistry for Engineering
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• v.32 no.5
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• pp.487-496
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• 2021

Microalgae is one of the promising biodiesel feedstock with high growth rates compared to those of terrestrial oil crops. Despite its numerous advantages, biodiesel production from microalgae needs to reduce energy demand and material costs further to go to commercialization. During solvent extraction of microalgal lipids, lipid-extracted algae (LEA) cell residue is generated as an organic solid waste, about 80-85% of original algal biomass, and requires an appropriate recycling or economic disposal. The resulting LEA still contains significant amount of carbohydrates, proteins, N, P, and other micronutrients. This review will focus on recent advancement in the utilization of LEA as: (i) utilization as nutrients or carbon sources for microalgae and other organisms, (ii) anaerobic digestion to produce biogas or co-fermentation to produce CH₄ and H₂, and (iii) conversion to other forms of biofuel through thermochemical degradation processes. Possible mutual benefits in the integration of microalgae cultivation-biodiesel production-resulting LEA with anaerobic digestion and thermochemical conversion are also discussed.

• Applied Chemistry for Engineering
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• v.32 no.5
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• pp.589-598
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• 2021

The purpose of this study was to analyze the efficiency with which phosphorylated spent coffee grounds (PSCG) remove cationic Cu(II) ions from an aqueous solution. The pHpzc of the SCG was 6.43, but it was lowered to 3.96 in the PSCG, confirming that an acidic functional group was attached to the surface of the PSCG. According to FT-IR analysis, phosphorylation of the SCG added P=O, P-O-C (aromatic), P=OOH, and P-O-P groups to the surface of the adsorbent, and the peaks of the carboxyl and OH groups were high and broad. Also, the specific surface area, mesopore range, and ion exchange capacity increased significantly by phosphorylation. The adsorption kinetics and isothermal experiments showed that Cu(II) adsorption using SCG and PSCG was explained by PSO and Langmuir models. The maximum Langmuir adsorption capacity of SCG and PSCG was 42.23 and 162.36 mg/g, respectively. The adsorption process of both SCG and PSCG was close to physical adsorption and endothermic reaction in which the adsorption efficiency increased with temperature. PSCG was very effective in adsorbing Cu(II) in aqueous solution, which has great advantages in terms of recycling resources and adsorbing heavy metals using waste materials.

• Environmental Engineering Research
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• v.24 no.2
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• pp.339-346
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• 2019

In this research, applicability of electrochemical technology in removing nitrogenous compounds from solid waste landfill leachate was examined. Novel cathode material was developed at laboratory by introducing a Cu layer on Al substrate (Cu/Al). Al and mild steel (MS) anodes were investigated for the efficiency in removing nitrogenous compounds from actual leachate samples collected from two open dump sites. Al anode showed better performances due to the effect of better electrocoagulation at Al surface compared to that at MS anode surface. Efficiency studies were carried out at a current density of $20mA/cm^2$ and at reaction duration of 6 h. Efficiency of removing nitrate-N using Al anode and developed Cu/Al cathode was around 90%. However, for raw leachate, total nitrogen (TN) removal efficiency was only around 30%. This is due to low ammonium-N removal as a result of low oxidation ability of Al. In addition to the removal of nitrogenous compounds, reactor showed about 30% removal of total organic carbon. Subsequently, raw leachate was diluted four times, to simulate pre-treated leachate. The diluted leachate was treated and around 88% removal of TN was achieved. Therefore, it can be said that the reactor would be good as a secondary or tertiary treatment step in a leachate treatment plant.

• Current Photovoltaic Research
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• v.7 no.1
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• pp.21-27
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• 2019

Lifetime of Si photovoltaics modules are about 25 years and a large amount of waste modules are expected to be discharged in the near future. Therefore, the extraction and collection of valuable metals out of discharged Si modules will be one of the important technologies. In this study, we demonstrated that supercritical $CO_2$ extraction method can be effectively used to remove Cu, one of the abundant elements in the module, as well as its oxide form, $Cu_2O$. Especially, we proved that the addition of hexane as co-solvent is effective for the removal of both materials. The optimal ratio of $CO_2$ and hexane was 4:1 at a fixed temperature and pressure of $250^{\circ}C$ and 250 bar, respectively. In addition, it was proven that the removal of $Cu_2O$ was preceded via reduction of $Cu_2O$ to Cu.

• The Journal of Economics, Marketing and Management
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• v.10 no.6
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• pp.39-46
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• 2022

Purpose: The purpose of this study is to look at the current status and cases of ESG at home and abroad, and through this, seek ways to activate the ESG strategy of domestic SMEs and suggest a direction. Research design, data and methodology: This study examines the current status of ESG management at home and abroad and examples of companies through related literature on ESG management and performance. Through this, the strategic direction of ESG management of domestic SMEs was presented. Results: Compared to the government and major corporations, SMEs can be said to lack ESG management activities. ESG activities include environmental activities such as carbon neutrality, waste management, eco-friendly supply chain management, establishment of safety and health processes to improve workers' environment, expansion of governance to guarantee autonomy and profitability such as fair trade, protection of social and shareholder rights such as anti-corruption, etc. should be based on Therefore, there are difficulties in ESG activities of SMEs that lack funds and manpower. Conclusions: Compared to the government and major corporations, SMEs can be said to lack ESG management activities However, it will be possible to establish and implement ESG management strategies based on the strengths of SMEs and the characteristics of each company.

• International Journal of Computer Science & Network Security
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• v.22 no.1
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• pp.85-92
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• 2022

In this article, we look at the application of BIM (Building Information Modeling) in sustainable infrastructures. In response to global warming, energy shortages, and environmental degradation, people are trying to build eco-friendly, low-carbon cities and promote eco-friendly homes. A "green" building is the entire life cycle of a building that includes maximizing the conservation of resources (energy, water, land, and materials), protecting the environment, reducing pollution, providing people with healthy, comfortable, and efficient use of space, and establishing harmony between nature and architecture. In the field of ecological and sustainable buildings, BIM modeling can be integrated into buildings with analog energy, air flow analysis, and solar building ecosystems. Using BIM technologies, you can reduce the amount of waste and improve the quality of construction. These technologies create "visualization" of digital building models through multidimensional digital design solutions that provide" modeling and analysis "of Scientific Collaboration Platforms for designers, architects, utility engineers, developers, and even end users. Moreover, BIM helps them use three-dimensional digital models in project design and construction and operational management.

• Journal of Soil and Groundwater Environment
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• v.27 no.1
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• pp.31-38
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• 2022

The common algae and industrial waste, chlorella and red mud, were co-pyrolyzed in carbon dioxide condition to fabricate iron-biochar composite. In order to investigate the direct effect of chlorella and red mud in the syngas generation and the property of biochar, experiments were performed using mixture samples of chlorella and red mud. The evolution of flammable gasses (H₂, CH₄, CO) was monitored during pyrolysis. The produced biochar composite was employed as a catalyst for persulfate activation for methylene blue removal. BET analysis indicated that the iron-biochar composite mainly possessed meso- and macropores. The XRD analysis revealed that hematite (Fe₂O₃) contained in red mud was transformed to Fe₃O₄ during co-pyrolysis. The composite effectively activated persulfate and removed methylene blue. Among the composite samples, the composite fabricated from the mixture composed of 1:2 chlorella:red mud showed the best performance in syngas generation and methylene blue removal.

• Journal of the Korean Society of Industry Convergence
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• v.25 no.6_3
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• pp.1247-1260
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• 2022

The steel industry accounts for about 5% of the total annual global energy consumption and more than 6% of the total anthropogenic carbon dioxide emissions. Therefore, there is a need to increase energy efficiency and reduce greenhouse gas emissions in these industries. The utilization of coke oven gas, a byproduct of the coke plant, is one of the main ways to achieve this goal. Coke oven gas used as a fuel in many steelmaking process is a hydrogen-rich gas with high energy potential, but it is commonly used as a heat source and is even released directly into the air after combustion reactions. In order to solve such resource waste and energy inefficiency, several alternatives have recently been proposed, such as separating and refining hydrogen directly from coke oven gas or converting it to syngas. Therefore, in this study, recent research trends on the separation and purification of hydrogen from coke oven gas and the production of syngas were introduced.

• Journal of Surface Science and Engineering
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• v.56 no.4
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• pp.259-264
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• 2023

As the demand for lithium-ion batteries, a key power source in electric vehicles and energy storage systems, continues to increase for achieving global carbon neutrality, there is a growing concern about the environmental impact of disposing of spent batteries. Extensive research is underway to develop efficient recycling methods. While hydrometallurgy and pyrometallurgy methods are commonly used to recover valuable metals from spent cathode materials, they have drawbacks including hazardous waste and complex processes. Hence, alternative recycling methods that are environmentally friendly are being explored. However, recycling spent cathode materials still remains complex and energy-intensive. This study focuses on a novel approach called solid-state synthesis, which aims at regenerating the performance of spent cathode materials. The method offers a simpler process and reduces energy consumption. Optimal heat treatment conditions were identified based on experimental results, contributing to the development of sustainable recycling technologies for lithium-ion batteries.