Reaction of carbon dioxide (CO₂) with minerals to generate stable carbonates, also known as CO₂ mineralization, has been regarded as one of the most promising methods for safe and permanent carbon storage. As a promising feedstock, basaltic rock has gained special interest, and elevating basalt carbonation efficiency with the reduction of negative environmental impact is the main challenge for CO₂ mineralization system development. Considering multiple potential positive effects of the CO₂ carrier, NaHCO₃, we conducted this study to experimentally evaluate the CO₂ storage efficiency during water-basalt-NaHCO₃ interactions under hydrothermal conditions at 200–300°C. The inclusion of NaHCO₃ was confirmed to drastically promote the alteration of basalt, especially at higher temperatures. As revealed by experiments conducted at the saturated vapor pressure of water, the carbon storage efficiency at 300°C reached 75 g/kg of basalt in 5 days, which was 12 times higher than that at 200°C. In such hydrothermal systems, basalt was carbonated to generate calcite (CaCO₃), where the Ca was mainly from plagioclase; Mg and Fe were incorporated into smectite, and Na in the saline system participated in the formation of Na silicates (i.e., analcime in the case of basalt). Due to the presence of additional Na in solution, all the released elements were consumed quickly with generation of secondary minerals in turn promoted basalt dissolution to release more Ca for CO₂ storage. This study illuminated the role of NaHCO₃ in basalt carbonation and provided technical backup to the design of advanced CO₂ mineralization systems.

Natural and anthropogenic chelating ligands play important roles in promoting mineral dissolution during water-rock interactions. To address the remaining issue of how chelating ligands participate in the dissolution of minerals, this study investigated the dissolution characteristics of seven types of silicate minerals in the presence of a chelating ligand, N,N-bis(carboxymethyl)-L-glutamic acid (GLDA), which is a glutamic acid derivative, through batch dissolution experiments. The results showed that the dissolution of all types of silicate minerals, i.e., olivine (nesosilicate), epidote (sorosilicate), tourmaline (cyclosilicate), enstatite (single-chain inosilicate), hornblende (double-chain inosilicate), biotite (phyllosilicate), and anorthite (tectosilicate), can be enhanced by up to two orders of magnitude at both pH 4 and 8. The chelating ligand particularly facilitated the dissolution of minerals with a higher Al content, such as tourmaline and anorthite. Furthermore, the presence of chelating ligands enhanced the leaching of not only metals but also Si from minerals, resulting in a more congruent characteristic of mineral dissolution. A possible mechanism is that the chelating ligand adsorbs onto the negatively charged the mineral surface, which attracts more H+ and polarizes Si-O and Mg-O bonds, thereby dissolving the minerals at a faster rate. These results have significant implications for understanding the dissolution of minerals in nature and for the application of chelating agents in geological and materials engineering.

This special issue comprises 12 papers from authors in 10 countries with new insights on the close coupling between magma as an energy and fluid source with hydrothermal systems as a primary control of magmatic behavior. Data and interpretation are provided on the rise of magma through a hydrothermal system, the relative timing of magmatic and hydrothermal events, the temporal evolution of supercritical aqueous fluids associated with ore formation, the magmatic and meteoric contributions of water to the systems, the big picture for the highly active Krafla Caldera, Iceland, as well as the implications of results from drilling at Krafla concerning the magma–hydrothermal boundary. Some of the more provocative concepts are that magma can intrude a hydrothermal system silently, that coplanar and coeval seismic events signal “magma fracking” beneath active volcanoes, that intrusive accumulations may far outlast volcanism, that arid climate favors formation of large magma chambers, and that even relatively dry rhyolite magma can convect rapidly and so lack a crystallizing mush roof. A shared theme is that hydrothermal and magmatic reservoirs need to be treated as a single system.

Renewable energy projects are critical for sustainable development, yet their success often hinges on local community acceptance. This study refines the Community Acceptance Framework to classify and better understand the social and behavioral factors that shape community responses to renewable energy projects. To support the reclassification, we draw selectively on three psychological concepts to refine definition and streamline categories. Based on a systematic review of 212 studies, we identified 29 influencing factors and categorized them into a seven-dimensional framework: social, economic, environmental, political, process, project details, and temporal. The findings reveal that financial capital, which reflects economic gains, emerges as the most frequently cited factor influencing local acceptance. However, when viewed dimensionally, the social dimension encompassing factors such as social capital, cognitive response, and cultural capital accounts for the largest share of influencing factors. Additionally, the often-overlooked political and temporal dimensions highlight the importance of governance quality and timely community engagement. While the framework offers a more robust and context-sensitive tool for analyzing acceptance dynamics, empirical validation is needed to assess its practical applicability. Nevertheless, the refined CAF can guide policymakers, researchers, and practitioners in designing renewable energy initiatives that are both technically sound, economically viable, and socially inclusive.