Pretreatment of flue gas prior to CO2 capture via amine scrubbing is important for maintaining CO2 capture efficiency and avoiding formation of toxic byproducts due to the presence of NOX. One flue gas cleaning method for that has increasingly gained attention is NOX scrubbing, in which NO is pre-oxidized to NO2 which can be absorbed using aqueous solutions containing suitable additives. While commonly used sulfur-based additives achieve high absorption efficiencies, they suffer from high consumption rates due to oxidative consumption. A recent study on phenolic additives demonstrated that e.g. 4-methylaminophenol could be used as efficient additive which has much lower consumption rates. This compound however is limited for industrial application due to environmental concerns. The present study aims to demonstrate the usage of bio-based phenolic polymers for NO2 absorption which should be more suitable for industrial usage on the example of lignin sulfonate. Additionally, vanillin was studied as a model compound to better understand NO2 absorption chemistry with such additives. Tests were conducted using lignin sulfonate at different pH values and additive concentrations with 50 ppm inlet NO2 at a total gas flow rate of 2.3 NL/min. Lignin sulfonate at 500 mg/100 mL and pH 9 maintained high NO2 absorption efficiency of approximately 90 %. Vanillin at 5 mM showed efficiencies of 91 % and 94 % at 50 and 100 ppm inlet NO2, respectively, at the same gas flow rate. With vanillin, absorption efficiency remained at a high level even after more than 1 mol NO2 per mole additive was absorbed, while sulfur-based additives showed a much lower ratio than 1 when fully consumed. NO2 absorption by the sulfur-based additives was successfully modeled, highlighting the lower chemical consumption of vanillin. Overall, these results demonstrate the high potential of lignin-based additives for NO2 scrubbing.
Pressurized hot water extraction (PHWE) is a green and effective method for lignocellulose fractionation. However, the utilization of ultrafine biomass, which is considered dust waste in industrial processes, was not well elucidated. Herein, the PHWE of ultrafine industrial hardwood dust with a particle size of 20-250 μm was investigated, and the dissolution effect was studied. To estimate the particle size effect, the PHWE of sawdust (250-1400 μm) was also performed. Obtained post-treated solids (PHWE solids) and hemicelluloses dissolved in liquid media (hydrolysates) were subjected to lignin and hemicellulose recovery using organic solvents, respectively. Comprehensive analysis revealed that the application of ultrafine dust was much more advantageous for the precipitation of dissolved hemicelluloses. For example, the highest amount of material precipitated from hydrolysates produced from dust and sawdust was about 70 and 40 wt% of total dissolved solids (TDS), respectively. Moreover, it was noted that particle size affected the composition of recovered precipitates. For instance, xylose content in the precipitates from dust-originated hydrolysate was 35% higher than that in material recovered from hydrolysate produced after PHWE of sawdust at similar conditions. The molar mass (Mw) of dust-originated extracts and their precipitates obtained using acetone as an anti-solvent was generally twice as high as that of materials obtained after PHWE of sawdust. The results of the study indicate that industrial hardwood dust could be a promising feedstock for hemicellulose recovery, and that the yield, properties, and composition of the recovered fractions could be adjusted by PHWE conditions applied.
Effective management of marine ecosystems requires understanding linkages between biodiversity and ecosystem functioning. While key species have been identified in many marine systems, the functions provided by different habitats have not been comprehensively synthesised in the region, limiting the ability to identify key habitats. Here, we assess the current state of knowledge on biodiversity and ecosystem functions associated with benthic and pelagic habitat types in the northern Baltic Sea. Drawing on literature, data and expert assessments, we evaluated 49 habitat types, identifying 750 habitat type-function linkages. Of these, 35
Breeding phenological responses to changing environments affect demographics and population persistence. However, inter-individual variation in adjustment of reproductive timing to predation risk has been overlooked. We thus tested whether increasing natural predation risk enhanced or homogenized reproductive timing of females differing in risk sensitivity. Using behavioral (flight initiation distance, FID) and cognitive (relative head volume) proxies of risk sensitivity, we analyzed laying dates of female common eiders (Somateria mollissima) breeding in SW Finland (Baltic Sea) relative to conspecifics under fluctuating predation pressure, while accounting for breeding experience and body condition. We found that high predation risk was associated with a divergence of female eider breeding phenologies depending on cognitive but not behavioral proxies of risk sensitivity. Accordingly, relatively large-headed females, assumed to be more risk-sensitive, bred later than small-headed ones following years of high adult or nest predation risk—plausibly reflecting extended nest prospecting in risk-sensitive individuals—leading to greater laying asynchrony. In contrast, females displaying longer FIDs (more risk-sensitive) bred earlier than those displaying shorter FIDs, but this response was irrespective of the level of predation risk. Because FID was measured late in incubation, we hypothesize that it may more strongly reflect state-dependent parental investment in the current breeding attempt than risk sensitivity during nest initiation, with higher parental investment promoting delayed escape. Additionally, experienced breeders bred earlier than inexperienced ones. More attention should be given to cognitive traits and behaviors associated with risk sensitivity to better understand variation in individual breeding phenology and synchrony.
Social outsiderhood - particularly loneliness and ostracism - has a significant impact on mental health issues such as internalizing symptoms (e.g., depression, anxiety) and externalizing symptoms (e.g., aggression, conduct problems). Yet, the mechanisms underlying these effects are multifaceted and likely include multiple mediating processes that may either amplify or mitigate the emergence of internalizing and externalizing symptoms. This cross-sectional study examines whether digital behaviors - social media use and gaming - mediate the relationship between school-based loneliness, school-based ostracism, and externalizing and internalizing symptoms in Finnish adolescents. Data were collected from 1,742 secondary school students (mean age 14.9 years; 47.6% male). Results reveal that both social media use and gaming were only weakly correlated with school-based loneliness, school-based ostracism, and mental health outcomes. Mediation analyses demonstrated that neither social media nor gaming robustly mediated the link between social disconnection and externalizing and internalizing symptoms. However, social media use weakly but significantly mediated the ostracism - internalizing symptoms link among girls, and gaming partially mediated the loneliness - internalizing symptoms link among boys. The findings suggest that digital behaviors are not primary explanations for the impact of school-based loneliness and ostracism on adolescent mental health. Future research should utilize longitudinal approaches and other measures of digital engagement to further clarify these relationships and identify alternative mediating processes.
