Scaling-Free Cathodes: Enabling Electrochemical Extraction of High-Purity Nano-CaCO3 and -Mg(OH)2 in Seawater.

For electrochemical application in seawater or brine, continuous scaling on cathodes will form insulation layers, making it nearly impossible to run an electrochemical reaction continuously. Herein, we report our discovery that a cathode consisting of conical nanobundle arrays with hydrophobic surfaces exhibits a unique scaling-free function. The hydrophobic surfaces will be covered with microbubbles created by electrolytic water splitting, which limits scale crystals from standing only on nanotips of conical nanobundles, and the bursting of large bubbles formed by the accumulation of microbubbles will cause a violent disturbance, removing scale crystals automatically from nanotips. Benefiting from the scaling-free properties of the cathode, high-purity nano-CaCO3 (98.9%) and nano-Mg(OH)2 (99.5%) were extracted from seawater. This novel scaling-free cathode is expected to eliminate the inherent limitations of electrochemical technology and open up a new route to seawater mining.

Sorting Out the Latest Advances in Separators and Pilot-Scale Microbial Electrochemical Systems for Wastewater Treatment: Concomitant Development, Practical Application, and Future Perspective.

To date, dozens of pilot-scale microbial fuel cell (MFC) devices have been successfully developed worldwide for treating various types of wastewater. The availability and configurations of separators are determining factors for the economic feasibility, efficiency, sustainability, and operability of these devices. Thus, the concomitant advances between the separators and pilot-scale MFC configurations deserve further clarification. The analysis of separator configurations has shown that their evolution proceeds as follows: from ion-selective to ion-non-selective, from nonpermeable to permeable, and from abiotic to biotic. Meanwhile, their cost is decreasing and their availability is increasing. Notably, the novel MFCs configured with biotic separators are superior to those configured with abiotic separators in terms of wastewater treatment efficiency and capital cost. Herein, a highly comprehensive review of pilot-scale MFCs (>100 L) has been conducted, and we conclude that the intensive stack of the liquid cathode configuration is more advantageous when wastewater treatment is the highest priority. The use of permeable biotic separators ensures hydrodynamic continuity within the MFCs and simplifies reactor configuration and operation. In addition, a systemic comparison is conducted between pilot-scale MFC devices and conventional decentralized wastewater treatment processes. MFCs showed comparable cost, higher efficiency, long-term stability, and significant superiority in carbon emission reduction. The development of separators has greatly contributed to the availability and usability of MFCs, which will play an important role in various wastewater treatment scenarios in the future.

Co-benefits and influencing factors exploration of air pollution and carbon reduction in China: Based on marginal abatement costs.

This study addresses the pressing need for cost-effective emission reduction strategies that maximize co-benefits in terms of air pollution and carbon emissions. Our research contributes to the literature by accurately measuring these co-benefits, thereby facilitating their prompt realization in different regions. We employ an input-output framework that integrates carbon emissions and air pollution, allowing us to calculate marginal abatement costs using the shadow price of undesired output. Through this approach, we quantify the co-benefits and analyze the factors influencing them at both spatiotemporal and factor levels using spatial kernel density and geographical detectors. Our findings reveal several key insights: (1) under joint emission reduction efforts, we observe average annual reduction rates of 6.46% for marginal pollution and 6.10% for carbon reduction costs. Importantly, we document an increase in co-benefits from 0.50 to 0.86, characterized by an initial fluctuation followed by a linear increase. (2) the marginal cost difference for carbon emission and pollution reduction in western China was 179.45 and 155.08 respectively, compared to 321.51 and 124.70 in the Northeast, highlighting the crucial role of regional differences in shaping co-benefit outcomes. (3) we identify a negative spatial spillover effect between provinces, which diminishes over time, leading to heterogeneous effects when local provincial co-benefits exceed a threshold of 0.9. (4) during the adjustment period, we find that the industrial structure exerts significant single and interactive effects on co-benefits. Additionally, we highlight the critical role of environmental governance investment and government intervention as drivers of co-benefits in the current era. By offering the quantification of co-benefits under the marginal abatement costs, our study provides valuable scientific insights for planning and implementing effective synergy strategies.

A novel carbon emission evaluation model for anaerobic-anoxic-oxic urban sewage treatment.

The proposal of the dual carbon goal and the blue economy in China has sparked a keen interest in carbon emissions reduction from sewage treatment. Carbon accounting in urban sewage plants serves as the foundation for carbon emission reduction in sewage treatment. This paper re-evaluated carbon accounting in the operational processes for urban sewage treatment plants to develop a novel carbon emission evaluation model for anaerobic-anoxic-oxic treatment plants. The results show that the carbon emissions generated by non-carbon dioxide gases far exceed the carbon emissions from carbon dioxide alone. Moreover, the recycling of sewage leads to carbon emissions reduction that offsets the carbon emissions generated during the operation of the sewage plant. Also, the carbon emissions generated by sewage treatment plants are lower than those generated by untreated sewage. The findings and insights provided in this paper provide valuable references for carbon accounting and the implementation of low-carbon practices in urban sewage treatment plants.

Reshaping water distribution topology from the carbon emission reduction perspective: An exploratory analysis of water distribution reliability.

As urban economies continue to evolve, the water distribution networks (WDNs) are expanding in scale and becoming more interconnected, leading to increased carbon emissions from operations and maintenance. Consequently, enhancing the stability and safety of WDNs while saving energy has emerged as a primary research focus. This study abandoned the original use of high economic costs for post-maintenance of WDNs. Instead, it reshaped the traditional water distribution topology to form a dynamic, storable, energy-efficient "WDN self-help" model. Drawing inspiration from the "deep tunnel" project in drainage systems, the proposal was to leverage underground spaces to create a deep aqueduct (DA) complementing the traditional WDN, forming a three-dimensional (3D) WDN. Hydraulic and water quality analyses of varying scales of the 3D WDN model demonstrated its superior ability to equalize node pressures, reduce pipeline head losses, and maintain water quality for end-users. Reliability assessments of the 3D WDN revealed enhanced system robustness for medium-to large-scale distributions, while energy consumption analyses indicated a significant increase in water supply energy utilization and significant long-term reductions in carbon footprint. A practical case study was presented to validate the effectiveness of the 3D WDN concept, confirming its ability to reliably distribute water even in the event of a failure. Finally, an estimate of the retrofit cost and the static payback period of the 3D WDN was conducted. This study aims to provide a theoretical reference for the renovation of water supply projects or the optimal design of new WDNs in the context of carbon neutrality.

Does carbon emission trading policy has emission reduction effect?-An empirical study based on quasi-natural experiment method.

As an important measure to reduce carbon emissions, carbon emission trading policy has been widely concerned and implemented around the world. The emission reduction effect of carbon emission trading policy has become a hot topic in theoretical researches and empirical explorations. Hence, this study aims to discuss the impact of the implementation of carbon emission trading policy on the reduction of carbon emissions, as well as the potential influencing paths and mechanisms. The quasi-nature experimental design is conducted with the data of 272 prefecture-level cities in China from 2007 to 2019. The propensity score matching (PSM) and difference-in-difference (DID) methods are adopted to explore and verify the causal relationship between carbon emission trading policy and carbon emissions. The results of this study are as follows: (1) the implementation of carbon emission policy can promote the reduction of carbon emission significantly; (2) the heterogeneity analysis results denote that the effect of carbon emission policy on the reduction of carbon emission varies among cities of different geographical locations; (3) mechanism analysis results indicate that technological capability is the main channel for carbon emission policy promotes the reduction of carbon emission; however, the effect of industry structure upgrading mechanisms is not significant. This manuscript responds to the theoretical issues of carbon emission and provides an empirical basis and references for further promoting the implementation of carbon emission policy.

Decoding enterprise digital transformation: External oversight and carbon emission reduction performance.

Enterprise digital transformation (EDT) is a strategic initiative that provides robust support for optimising resource allocation, fosters business innovation, and significantly impacts ecological environment to increase financial performance. This study re-examines the substantial contributions of EDT to climate change mitigation. Drawing on data from Chinese A-share listed companies from 2010 to 2021, we investigated the changes and mechanisms influencing carbon emissions reduction performance (CERP) of enterprises undergoing digital transformation. The empirical results indicate that EDT actively contributes to enhancing the CERP of enterprises, with a more pronounced effect observed in non-polluting industries, state-owned enterprises, and manufacturing companies. Furthermore, empirical findings from mechanism tests reveal that EDT effectively improves the CERP by driving green technological innovation, strengthening industry chain connections, and enhancing capacity utilisation. Finally, within external oversight groups, particularly in government and investor supervision, the enhancement of enterprise CERP is more significant, highlighting the crucial role of external oversight in the EDT process.

Study on regional carbon quota allocation at provincial level in China from the perspective of carbon peak.

This paper constructs a carbon quota allocation index that takes into account equity, efficiency and ecological construction, and calculates carbon emissions and energy consumption data in important periods based on the expected carbon emission targets and economic and social development indicators of the Chinese government. Based on the calculated carbon emissions, the zero-sum game data Envelopment model (ZSG-DEA) is used to discuss the initial allocation of regional quotas and the optimal carbon quota scheme. The results show that:(1) there is a large gap between the optimal carbon quota and the initial carbon quota allocation in Shandong, Guangdong, Jiangsu and other provinces in 2025, and the implementation of emission reduction measures should be accelerated. (2) By 2030, the final allocation of Beijing, Tianjin, Inner Mongolia, Qinghai, Shanghai, Ningxia, Liaoning and Xinjiang will be positive. The provinces with negative final allocation should carry out the work of carbon peak as soon as possible to avoid increasing the pressure of emission reduction in the future. (3) The central region faces greater pressure of emission reduction, while the western region can accept the transfer of carbon emissions from other regions over time. The research conclusions have important policy implications for establishing a fair and effective carbon quota allocation mechanism, achieving the national total carbon emission control target, stimulating the vitality of the unified carbon market, and promoting regional coordinated emission reduction.

Digital governance and carbon emission reduction: Evidence from "National Pilot Policy of Information Benefiting the People" in China.

Promoting digital governance is crucial for the Chinese government's governance reform. This study utilizes panel data covering 280 cities in China to examine the influence of government digital governance on reducing carbon emissions. The "National Pilot Policy of Information Benefiting the People," implemented in 2014, serves as the quasi-natural experiment for the analysis. The study employs the difference-in-difference (DID) methodology to indicate that improving the government's digital capacity contributes to reducing carbon emissions, which is robust to several robustness tests. Government digital governance facilitates the reduction of carbon emissions primarily via three mechanisms: developing green finance, gathering green talents, and promoting green technology innovation. Enhanced digital governance by the government exerts a more pronounced effect on reducing carbon emissions in cities in the eastern region, smaller municipalities, and resource-dependent municipalities. Additionally, current policies have notably decreased carbon emissions in the pilot cities, though a lag exists in the policy spillover effect affecting neighboring cities. This study investigates the influence of government digital governance on reducing carbon emissions through the lens of digital transformation. It offers valuable empirical insights for enhancing the governance capabilities of the Chinese government in the new era and facilitating the achievement of carbon reduction targets in urban areas.

Medical waste incineration fly ash-based magnesium potassium phosphate cement: Calcium-reinforced chlorine solidification/stabilization mechanism and optimized carbon reduction process strategy.

The traditional solidification/stabilization (S/S) technology, Ordinary Portland Cement (OPC), has been widely criticized due to its poor resistance to chloride and significant carbon emissions. Herein, a S/S strategy based on magnesium potassium phosphate cement (MKPC) was developed for the medical waste incineration fly ash (MFA) disposal, which harmonized the chlorine stabilization rate and potential carbon emissions. The in-situ XRD results indicated that the Cl- was efficiently immobilized in the MKPC system with coexisting Ca2+ by the formation of stable Ca5(PO4)3Cl through direct precipitation or intermediate transformation (the Cl- immobilization rate was up to 77.29%). Additionally, the MFA-based MKPC also demonstrated a compressive strength of up to 39.6 MPa, along with an immobilization rate exceeding 90% for heavy metals. Notably, despite the deterioration of the aforementioned S/S performances with increasing MFA incorporation, the potential carbon emissions associated with the entire S/S process were significantly reduced. According to the Life Cycle Assessment, the potential carbon emissions decreased to 8.35 × 102 kg CO2-eq when the MFA reached the blending equilibrium point (17.68 wt.%), while the Cl- immobilization rate still remained above 65%, achieving an acceptable equilibrium. This work proposes a low-carbon preparation strategy for MKPC that realizes chlorine stabilization, which is instructive for the design of S/S materials.

Spatial and temporal evolution characteristics and spillover effects of China's regional carbon emissions.

China's carbon emissions account for approximately a quarter of the world's total greenhouse gas emissions. In 2020, China's fossil fuels accounted for approximately 85% of the primary energy demand, with coal alone accounting for 60%. Considering the severe global warming situation, it is necessary to reveal the spatial and temporal differences and analyze the spillover effects of carbon emissions between regions. In this study, a positive and significant spatial correlation between regional carbon emissions in China was found using an exploratory spatial data analysis. The spatial Durbin model was then utilized to explore the direct and spillover effects of factors that included economic growth, the energy intensity, and the level of technological innovation on regional carbon emissions. Whether a direct effect or a spillover effect, economic growth and improvements in the regional levels of technological innovation had significant inhibitory effects on carbon emissions both in the long term and in the short term. Specifically, an increase of 1% in the level of technological innovation led to a reduction of approximately 0.17% in the region's carbon emissions. However, a growth in the energy intensity will increase carbon emissions. In addition, an increase in the technological input intensity will lead to an increase in carbon emissions in local regions. However, an increase in neighboring regions will restrain carbon emissions in a local region. Based on these findings, it is recommended that the government accelerate regional innovation synergies and increase investment in clean energy technologies.

Can low-carbon city construction reduce carbon intensity？Empirical evidence from low-carbon city pilot policy in China.

Low-carbon city pilot policy (LCCP) is an innovative initiative for promoting low-carbon transformation and green development in China, which is of great practical significance for realizing China's vision of "double carbon" on schedule. In this study, LCCP implementation is treated as a "quasi-natural experiment," and the spatial difference-in-differences approach is used to quantitatively examine the carbon reduction effects and impact mechanisms of LCCP using panel data of 283 cities in China from 2006 to 2017. The results show that since 2011, LCCP has significantly reduced the carbon intensity of the pilot cities by 0.13%, resulting from the effects of urban environmental governance, industrial structure optimization, and urban innovation level improvement. Meanwhile, there is a significant spatial spillover effect which results in a 0.9% reduction in carbon intensity of neighboring cities. The spatial spillover range of the reduction effect is about 500 km, which decays with distance. Moreover, the carbon reduction effect of the policy is spatially and temporally heterogeneous, and the reduction effect is more significant for resource-based cities, and different for resource-based cities in different development stages. The above findings provide useful policy insights for constructing low-carbon cities under China's "dual carbon goals" and help to realize the win-win path of green development and carbon reduction transition.

How does digital technology promote carbon emission reduction? Empirical evidence based on e-commerce pilot city policy in China.

Digital technology is an effective way to realize the carbon neutrality target in China. Therefore, based on panel data at the city level in China from 2006 to 2016, we take the e-commerce pilot policy as a quasi-natural experiment, using the staggered difference-in-differences (DID) method to explore the effect of digital technology development on carbon emissions and its transmission mechanism. The conclusion of this paper shows that (ⅰ) the e-commerce pilot policy has significantly reduced carbon emissions. After a series of robustness tests, this empirical conclusion is still valid. (ⅱ) The inhibitory effect of different waves of e-commerce pilot cities on carbon emissions sequentially decreases. The e-commerce pilot policy has a greater effect on reducing carbon emissions in non-old industrial based cities and non-resource-based cities. (ⅲ) Implementing the e-commerce pilot city policy mainly reduces urban carbon emissions by optimizing resource allocation, reducing energy consumption and upgrading the industrial structure. (ⅳ) In addition, implementing the e-commerce pilot city policy has a significant positive carbon-reducing linkage effect with the carbon trading pilot policy and the low-carbon city pilot policy. The findings of this paper provide empirical evidence for carbon emission reduction, which has implications for upgrading urban construction patterns and promoting green urban development.

Towards low-carbon development: The role of industrial robots in decarbonization in Chinese cities.

Technological advancements have played a key role in improving energy efficiency and reducing emissions, and industrial robots are important carriers of intelligent manufacturing and industrial upgrading. Although various countries and regions are under pressure to reduce their carbon emissions, a consensus has not been reached on whether industrial robots can help. This study investigates how industrial robots affect carbon emissions by categorizing industry data from the International Federation of Robotics (IFR, 2010-2018) into city-level variables. The empirical finding revealed that cities' carbon emissions have been significantly reduced by the application of industrial robots. By using the penetration of robots in Chinese cities as an instrumental variable constructed through the combination of employment level and robot imports, the beneficial role of robots is further verified by a plausibly exogenous test. The mechanism analysis revealed that industrial robots contribute to cities' decarbonization by enhancing energy efficiency and green technology efficiency. The heterogeneity analysis showed that the effect of industrial robots on decarbonization is more pronounced in megacities, advanced manufacturing bases, and low-carbon pilot cities. This study empirically confirms the positive role of industrial robots in carbon emission reduction, provides evidence for industrial robots' technical characteristics of decarbonization, and proposes novel ideas for achieving net-zero carbon emissions.

Suitability evaluation and potential estimation of photovoltaic power generation and carbon emission reduction in the Qinghai-Tibet Plateau.

The expansion of power development industry is facing enormous pressure to reduce carbon emissions in the context of global decarbonization. Using solar energy instead of traditional fossil energy to adjust energy structure is one of the important means for reducing carbon emissions. Existing research focuses on the evaluation of the generation potential of centralized or distributed photovoltaic power plants, rather than the comprehensive evaluation of multi-type power plants. Based on multi-source remote sensing data for information extraction and suitability evaluation, this paper develops a method to comprehensively evaluate the construction potential of multi-type photovoltaic power stations and determine the potential of photovoltaic power generation and carbon emission reduction on the Qinghai-Tibet Plateau (QTP). The results showed that estimating the power generation potential of only single-type photovoltaic power stations cannot accurately reflect the photovoltaic power generation potential of QTP. It is also demonstrated that the emission reduction effect of the photovoltaic power generation in all prefecture-level cities of QTP can meet national emission reduction targets, showing high annual power generation potential, of which 86.59% is concentrated in Qinghai province's Guoluo, Yushu, and Haixi. An accurate estimation of the photovoltaic power generation potential in QTP can provide a useful theoretical basis for developing carbon-saving and emission reduction strategies for clean energy in China.

Total-factor energy efficiency of ten major global energy-consuming countries.

Improving energy efficiency is regarded as a key path to tackling global warming and achieving the Sustainable Development Goals (SDGs). In 2020, the energy consumption of the world's ten major energy-consuming countries accounted for 66.8% of the global total. This paper applied data envelopment analysis (DEA) to calculate these ten major energy-consuming countries' total-factor energy efficiency (TFEE) at national and sectoral levels from 2001-2020, and explored the influencing factors of total-factor energy efficiency with the Tobit regression model. The results showed significant difference in the ten countries' energy efficiency. The United States and Germany topped the list for total-factor energy efficiency, while China and India were at the bottom. Meanwhile, the energy efficiency of the industrial subsector has increased significantly over the past two decades, while that of the other subsectors has been relatively flat. The industrial structure upgrading, per capita GDP, energy consumption structure, and foreign direct investment had significant impacts on energy efficiency with national heterogeneity. Energy consumption structure and GDP per capita were determinative factors of energy efficiency.

Application of the IoT in the Food Supply Chain─From the Perspective of Carbon Mitigation.

With the rising demands on supply chain transparency and food security, the rapid outspread of the Internet of Things (IoT) to improve logistical efficiency, and the rising penetration of sensor technology into daily life, the extensive integration of the IoT in the food sector is well anticipated. A perspective on potential life cycle trade-offs in regard to the type of integration is necessary. We conduct life cycle assessment (LCA) integrated with shelf life-food loss (SL-FL) models, showing an overall 5-fold leverage on carbon reduction, which is diet dependent and a function of income. Meat presents the highest leverage, 35 ± 11-times, owing to its high carbon footprint. Two-thirds (65%) of global sensors (1 billion) engaged in monitoring fruits and vegetables can mitigate less than 7% of the total reduced carbon emissions. Despite the expected carbon emission reductions, widespread adoption of the IoT faces multiple challenges such as high costs, difficulties in social acceptance, and regional variability in technological development. Furthermore, changes in the distribution of transportation resources and dealer service models, requirements regarding the accuracy of sensor data analysis, efficient and persistent operation of devices, development of agricultural infrastructure, and farmer education and training have all increased uncertainty. Nonetheless, the research trend in smart sensors toward smaller chips and the potential integration of machine learning or blockchain as further steps make it possible to leverage these advantages to facilitate market penetration. These insights facilitate the future optimization of the application of IoT sensors for sustainability.

Simultaneous medium chain fatty acids production and process carbon emissions reduction in a continuous-flow reactor: Re-understanding of carbon flow distribution.

Due to its wide application and high value, the production of medium chain fatty acids (MCFAs) from waste biomass has become one of the worldwide research hotspots. Increasing the carbon element participation from short-chain fatty acids to the form of MCFAs is also conductive to reduce the release of biogas from biological treatment process, because carbon is in the form of MCFAs instead of biogas which directly contribute to process carbon emissions reduction. However, many barriers limiting MCFAs production and application remain to be resolved. Aiming continuous MCFAs production from lactate-rich waste biomass, this study optimized the operation conditions and clarified the main limiting factors and possible mechanisms. The maximum caproic acid concentration of 2.757 g/L were obtained at the Upflow Velocity (ULV) of 1.15 m/h and pH 4.9-5.1. Caproiciproducens, Pseudoramibacter, norank_f_Eubacteriaceae, and Oscillibacter were identified to be the dominant microbial genus responsible for MCFAs production from lactate. The reduction of carbon emissions calculation was also studied in the present processes.

A systematic construction of water-electricity cogeneration and thermal membrane coupling desalination technology using the waste heat in steel industry.

The widespread use of fossil energy emits a large amount of carbon dioxide, leading to the greenhouse effect and global warming. The essence of reducing carbon emissions is to achieve higher-quality sustainable development. The recycling of waste heat in the iron and steel industry is of great significance to reducing carbon emissions. Aiming at the problem of insufficient utilization of gas in iron and steel industry and the development of seawater desalination industry, a water-electricity cogeneration and thermal membrane coupling technology is established. Low-temperature multi-effect distillation seawater desalination device is directly connected with steam turbine generator, which uses gas to generate electricity. After generating electricity, negative pressure exhaust at the end of steam turbine is used for seawater desalination. The thermal efficiency of the system is increased to over 80%, the waste heat is effectively utilized, and the carbon emission in the thermal desalination process is reduced. At the same time, the high-efficiency removal and resource utilization of salt in concentrated seawater are realized. The recovery ratio of freshwater is over 55%, the salt content of freshwater is below 500 mg/L, and the salt content of seawater concentrated by membrane method can reach 79,450 mg/L. A new comprehensive utilization and recycling system of seawater has been constructed to realize efficient recycling of energy resources and promote the development process of carbon emission reduction.

Characteristic and calculation on the co-contribution in the bio-H2 energy recovery enhancement with low temperature pretreated peanut shell as co-substrate.

Bio-H2 production from organic wastewater together with lignocellulose wastes not only achieved the H2 energy recovery, but also be beneficial to carbon emission reduction and carbon neutralization. In order to obtain higher energy recoveries, promotion attempts were performed in bio-H2 fermentation with low temperature (-80-0 °C) pretreated peanut shell powder (PSP) as co-substrate. A maximum H2 production of 109.2 mL was obtained as almost double of the sum from the same amount of untreated PSP and glucose as sole substrate. The enhancement was co-contributed by 44% from PSP supplementary, 35% from low-temperature pretreatment, and 2.8% from buffer effect and acidification, respectively, and realized through C/N balancing, PSP conversion influencing, fermentative pH buffering and time prolonging. The experimental results uncovered the co-contribution realization ways of supplementing low-temperature pretreated lignocellulose wastes in the bio-H2 fermentation system, and provided mechanism support for application potential of low-temperature pretreatment on lignocellulose wastes in cold regions.