In present work, environmentally benign green aragonite crystals were synthesized from waste chicken eggshells and bivalve seashells through a simple and low-cost wet carbonation method. This method involves a constant stirring of calcium oxide slurry and magnesium chloride suspension in aqueous solution with constraint carbon dioxide injection at 80 °C. The physicochemical properties of the synthesized aragonite were further compared with the aragonite synthesized from commercial calcium oxide. The morphological analysis, such as acicular shape and optimum aspect ratio (~21), were confirmed by scanning electron microscopy. The average crystal size (10–30 µm) and specific surface area (2–18 m² g⁻¹) were determined by particle size and Brunauer–Emmett–Teller analysis, respectively. Moreover, a schematic crystal growth mechanism was proposed to demonstrate the genesis and progression of aragonite crystal. Green aragonite can bridge the void for numerous applications and holds the potential for the commercial-scale synthesis with eggshells and bivalve seashells as low-cost precursors.

In 2008, the Republic of Korea announced the Low Carbon Green Growth vision as the national growth engine. This Green Growth vision invested in developing state-of-the-art green technologies to minimize greenhouse gas and pollutant emissions. Following a change in administration, Korean green technologies were re-categorized into six core technologies for climate change response in 2014, and ten core technologies for carbon-neutrality in 2021. The government proposed the realization of an inclusive green state in the 3rd Five-Year Green Growth Plan announced in 2019. Following the Green New Deal announced in 2020, green technology policies and investments continue, with the declaration of 2050 carbon neutrality. In the past two years, government policies from the 2050 Carbon Neutrality Strategy to the 2050 Carbon-Neutral Scenario consider Carbon Capture Utilization and Storage (CCUS) as an important technology to reduce CO₂ and meet carbon-neutral goals. This study examines major green technology policy trends, focusing on CCUS, beginning with the Green Growth era in 2008 to today. R&D investment costs related to green technology during the green growth period and CCUS-related investment costs over the past 10 years (2011–2020) are utilized in statistical analyses (correlation, trend) to investigate and analyze investment volatility in green and CCUS technologies related to climate change. Finally, the study will provide basic information for establishing CCUS-related R&D policies, which will continue to increase in achieving carbon neutrality.

In 2016, the Korean government selected carbon capture and utilization (CCU) as one of the national strategic projects and presented a detailed roadmap to reduce greenhouse gas emissions and to create new climate industries through early demonstration of CCU technology. The Korean government also established the 2030 Greenhouse Gas Reduction Roadmap in 2016 and included carbon capture, utilization, and storage (CCUS) technology in the new energy industry sector as a CCU technology. The Korean government recognizes the importance of CCUS technology as a mid- to long-term measure to reduce greenhouse gas emissions and implements policies related to technological development. The United States (U.S.), Germany, and China also expect CCUS technology to play a major role in reducing greenhouse gases in the industrial sector in terms of climate and energy policy. This study analyzed the CCU-related policies and technological trends in the U.S., Germany, and China, including major climate and energy plans, driving roadmaps, some government-led projects, and institutional support systems. This work also statistically analyzed 447 CCU and CCUS projects in Korea between 2010 and 2017. It is expected to contribute to responding to climate change, promoting domestic greenhouse gas reduction, and creating future growth engines, as well as to be used as basic data for establishing CCU-related policies in Korea.

To use calcite mud waste generated from the paper production process, calcite mud was treated by calcination and then applied as a sorbent agent to remove phosphorus from an aqueous solution. The pre-treatment muds were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, and X-ray diffraction. The effects of calcite mud with different calcination temperatures on phosphorus removal were investigated. Different sorbent dosages, contact times, and initial phosphorus concentration conditions were also studied to understand the phosphorus removal mechanism. The results show that phosphorus removal efficiency was increased by increasing the calcination temperature of the mud. The phosphorus removal efficiency over 10 min increased by 35%, 82%, 98%, and 100% with 4.5, 6.75, 9.0, and 11.25 mg, respectively, of calcite mud calcined at 1000 °C. However, the efficiency decreased as initial phosphorus concentration increased. To study the phosphorus removal trend, the pseudo-first-order, pseudo-second-order, and intraparticle diffusion kinetic models were used. The Langmuir and Freundlich isotherm models were also used to further investigate the phosphorus adsorption mechanism characteristics of the calcite mud.

In September 2015, the United Nations included ‘sustainable consumption and production’ as part of its 12th goal of sustainable development. The EU announced its Circular Economic Package in December 2015 to move from the existing linear economic structure to the net environmental system. Recycling of household waste has become more significant as a circular economic policy has been implemented to reflow waste into the economy through recycling worldwide. In this study, Korea’s household waste generation for 20 years from 1998 to 2017 was analyzed through statistical techniques. Waste generation tended to increase in the order of plastics and cans, and papers tended to decrease. The amount of bottle wastes has been on the decline after increasing. A questionnaire survey on recycling priority was conducted on 261 people, including participants in the EARTH-2019 recycling experience hall, using the analytic hierarchy process (AHP) technique. According to the survey, the recycling priorities of six types of household waste are (first) plastic, (second) cans, viny, scrap metals, (third) paper, and (fourth) bottles. Statistical analysis of mid- to long-term household waste generation and AHP-based household waste recycling priority survey results can be used as basic data, such as environmental analysis in Korea’s recycling-related policies and research.