Estimating global 0.1° scale gridded anthropogenic CO2 emissions using TROPOMI NO2 and a data-driven method.

Satellite remote sensing is a promising approach for monitoring global CO2 emissions. However, existing satellite-based CO2 observations are too coarse to meet the requirements of fine-scale global mapping. We propose a novel data-driven method to estimate global anthropogenic CO2 emissions at a 0.1° scale, which integrates emissions inventories and satellite data while bypassing the inadequate accuracy of CO2 observations. Due to the co-emitted anthropogenic emissions of nitrogen oxides (NOx = NO + NO2) and CO2, high-resolution NO2 measurements from the TROPOspheric Monitoring Instrument (TROPOMI) are employed to map the global anthropogenic emissions at a global 0.1° scale. We construct the driving features from NO2 data and also incorporate gridded CO2/NOx emission ratios and NOx/NO2 conversion ratios as driving data to describe co-emissions. Both ratios are predicted using a long short-term memory (LSTM) neural network (with an R2 of 0.984 for the CO2/NOx emission ratio and an R2 of 0.980 for the NOx/NO2 conversion ratio). The data-driven model for estimating anthropogenic CO2 emissions is implemented by random forest regression (RFR) and trained using the Emissions Database for Global Atmospheric Research (EDGAR). The satellite-based anthropogenic CO2 emission dataset at a global 0.1° scale agrees well with the national CO2 emission inventories (an R2 of 0.998 with Global Carbon Budget (GCB) and an R2 of 0.996 with EDGAR) and consistent with city-level emission estimates from Carbon Monitor Cities (CMC) with the R2 of 0.824. This data-driven method based on satellite-observed NO2 provides a new perspective for fine-resolution anthropogenic CO2 emissions estimation.

Rapid decline of carbon monoxide emissions in the Fenwei Plain in China during the three-year Action Plan on defending the blue sky.

The Fenwei Plain is one of China's most polluted regions, with poor atmospheric dispersion conditions and an outdated energy structure. After implementing multiple policies in recent years, significant reductions in air pollutant concentrations were observed. In this study, based on the Lagrangian-Bayesian inversion framework FLEXINVERT, we constructed a variable resolution inversion system focusing on the Fenwei Plain and inferred the carbon monoxide (CO) emissions using in-situ atmospheric CO observations from April 2014 to March 2020. We analyzed the spatiotemporal variations of the CO emissions and discussed their causes, especially the effect of the "Three-year Action Plan on Defending the Blue Sky" (TAPDBS). Before the policy, CO emissions temporarily increased, and the overall decrease in CO emissions per unit of Gross Domestic Product (GDP) slowed down. When the policy was implemented, CO emission fluxes declined sharply, with an average drop of 28%, accompanied by an even higher 37% decrease of CO emission per GDP. The reasons for the decline in CO emissions in Shanxi, Shaanxi and Henan are diverse. The decrease in energy intensity is the reason for CO emission reduction in Shannxi and Henan province but not in Shanxi province. This research fills the gap in emission information in recent years and confirms that TAPDBS has brought a breakthrough in both economic development and air quality protection in the Fenwei Plain.

[Challenges Regarding the Co-emission of Emerging Pollutants to Eco-environmental Monitoring and Management].

Emerging pollutants have drawn global concerns under rapid urbanization and industrialization. However, research has been relatively independent on specific groups of pollutants due to the limitation of the discipline. In this study, from the perspective of interdisciplinary research, taking the fluorochemical industry as an example, two major categories of emerging pollutants, per-and polyfluoroalkyl substances (PFAS) and ozone-depleting substances (ODS), were discussed regarding their co-emission. The co-production mechanism of the two types of pollutants were discussed from the production processes to reveal their internal relationship; their differences and cross-processes in the emission routes were analyzed, as well as the technical approaches and challenges required in sample collection, pretreatment, and instrumental analysis. The eco-environmental effects, including ecological and human health risks, ozone depletion, and global warming effects caused by the two types of pollutants in different media were comprehensively summarized. We also further expanded the perspectives of stakeholder analysis, life cycle analysis, and mass balance analysis to provide suggestions for further research and management of emerging pollutant co-emissions.

Preparation of activated sewage sludge char for low temperature De-NOx and its CO emission inhibition.

Sewage sludge (SS) char can be potentially applied to De-NOx processes but it should be active enough and the relevant CO emissions should be controlled. In this paper activated SS chars have been prepared by using a simple KOH impregnation-carbonisation method and the activated chars are applied to remove NOx from flue gases within temperature range of 100-250 °C, acting as both reductants and catalysts. Special attention is paid to inhibiting CO emission in the process. Four reductive agents are adopted to check the catalytic effect of the activated SS chars. The results show that the activated SS chars (i.e. SC-KOHs) present a higher adsorption-reduction ability with much lower CO emission than that of non-activated SS chars (i.e. SC-Raws). SC-KOH produced at 800 °C (SC-KOH-800) shows obvious chemical adsorption behaviors, its adsorption capacity for NO is higher than 8.06 mg.L-1, superior to the coal-based activated carbon. Hydrazine hydrate is found to enhance De-NOx performance with SC-KOHs acting as catalysts, especially at higher temperatures. However, the De-NOx efficiency decreased when ammonia, urea and urea involved reductants were used. The physicochemical structure of the SS chars was characterized to show that the SC-KOHs are more porous with higher BET areas and pore volumes. Simultaneously, the SC-KOHs are crystallized to much lower extent, less graphitised, but have richer O-containing functional groups and zeolite structure on the surface when compared to the SC-Raws, which contributed to their high activities. Moreover, SC-KOH-800 can be recommended as the suitable adsorbent/catalyst for De-NOx within 100-250 °C.

Combined effect of fuel-design and after-treatment system on reduction of local and global emissions from CI engine.

This experimental study aims to mitigate harmful emissions from a CI engine using bio-energy with carbon capture and storage (BECCS) approach. The engine used for this experimental work is a single cylinder CI engine with a rated power of 5.2 kW at a constant speed of 1500 rpm. The BECCS approach is a combination of plant-based biofuels and carbon capture and storage (CCS) system. The whole investigation was done in four phases: (1) Substituting diesel with Karanja oil methyl ester (KOME) (2) Equal volume blending of Orange oil (ORG) with KOME (3) 20% blending of n-butanol (B) with KOME-ORG blend (4) CCS system with zeolite based non-selective catalytic reduction (NSCR) and mono ethanolamine (MEA) based selective non-catalytic reduction (SNCR) system with KOME-ORG + B20 blend. The experimental results show that substitution of diesel with KOME reduces smoke emission, but increases NO and CO2 emission. KOME-ORG blend reduces CO2 and smoke emissions with high NO emission due to combustion improvement. In comparison with the sole combustion of KOME at full load condition, the combination of KOME-ORG + B20 as bio-fuel with zeolite based post-combustion treatment system resulted in a maximum reduction of NO, smoke and CO2 emission by 41%, 19% and 15% respectively.

Sample treatment in Mössbauer spectroscopy for protein-related analyses: Nondestructive possibilities to look inside metal-containing biosystems.

In this review, the unique possibilities are considered of the 57Fe transmission (TMS) and 57Co emission (EMS) variants of Mössbauer (nuclear γ-resonance) spectroscopy as nondestructive techniques with minimal sample preparation/treatment and a significant analytical potential, with a focus on the analysis of cation-binding sites in metalloproteins. The techniques are shown to provide unique structural and quantitative information on the coordination microenvironment, the chemical state and transformations of the Mössbauer nuclides in sophisticated metal-containing proteins, including those within complicated supramolecular structures, and in microbial cells or tissues. Recent representative examples of analyses of Fe-containing proteins by 57Fe TMS are briefly discussed, along with the newly emerging data on using 57Co EMS for probing the structural organisation of 57Co-doped cation-binding sites in sophisticated biocomplexes including metalloenzymes. Finally, some rare or exotic applications of Mössbauer spectroscopy (including the synchrotron-based methodology) in protein-related studies are outlined.