RESUMO
Activated coke is a type of commonly used adsorbent for benzene series VOCs such as toluene, but traditional microporous activated coke usually faces the challenge of poor regeneration performance. Herein, based on self-made activated cokes with typical pore configuration, we found that adsorption and regeneration of toluene can be simultaneously enhanced by constructing hierarchical pore in activated coke. Correlations of pore configuration with toluene adsorption capacity and regeneration efficiency reveal that micropore contributes for strong toluene adsorption; meso-macropore provides mass transfer channel for toluene desorption and regeneration process. Hierarchical porous activated coke prepared from Zhundong subbituminous coal not only achieves the highest toluene adsorption capacity of 340.92 mg·g-1, but also can retain more than 90% of initial adsorption capacity after five adsorption-regeneration cycles. By contrast, micropore-dominant activated cokes can only retain 70% of initial adsorption capacity. Adsorption kinetic modelling on adsorption breakthrough curves shows that hierarchical porous activated coke prepared from Zhundong subbituminous coal exhibits high adsorption and diffusion rate constants of 14.39 and 33.45 min-1, respectively, much higher than those of micropore-dominant activated cokes. Due to the accelerated surface adsorption and diffusion processes induced by meso-macropore, toluene adsorption and regeneration behavior can be simultaneously improved. Results from this work validated the role of pore hierarchy in toluene adsorption-regeneration process, providing guidance for designing high-performance activated coke with synergistically improved toluene adsorption capacity and regeneration performance.
Assuntos
Coque , Tolueno , Tolueno/química , Adsorção , Cinética , PorosidadeRESUMO
Background: The current investigation examines the association between artificial sweetener (AS) consumption and the likelihood of developing chronic kidney disease (CKD), along with its impact on kidney function. Methods: We utilized data from the National Health and Nutrition Examination Survey from 2003-2006 to conduct covariance analysis and weighted adjusted logistic regression, aiming to assess the association between artificial sweetener intake and CKD risk, as well as kidney function indicators. Subsequently, we employed Mendelian randomization methods to validate the causal relationship between the intake of artificial sweeteners, CKD risk, and kidney function indicators. Instrumental variable analysis using inverse-variance weighting and Robust adjusted profile score were the primary analytical methods employed. Results: A total of 20,470 participants were included in the study, with 1,257 participants ultimately included in the analysis. In all adjusted logistic regression models, no significant association was found between the intake of artificial sweeteners and CKD risk. Similarly, the summary odds ratios (OR) for each unit change in genetically predicted CKD risk were 2.14 (95% CI: 0.83, 5.21, p = 0.092), 1.41 (95% CI: 0.54, 3.63, p = 0.482), and 1.50 (95% CI: 0.50, 4.52, p = 0.468) for the impact of artificial sweeteners added to cereals, tea, and coffee, respectively. It was only observed that adding artificial sweeteners to coffee was associated with a modest reduction in urinary albumin-to-creatinine ratio (OR = 0.94, 95% CI: -0.108, -0.022, p = 0.003), the effect appeared to be relatively small and may not directly impact the individual level. Conclusion: Our study does not support a causal relationship between artificial sweetener intake and the risk of CKD. However, due to the limitations and potential confounding factors, these findings need to be further validated through larger sample sizes in observational studies and Mendelian randomization analyses.