Porous Polymeric Electrodes for Electrochemical Carbon Dioxide Capture.

Carbon capture is a promising technology to mitigate greenhouse gas emissions to achieve net carbon neutrality. Electro-swing reactive adsorption has emerged as an attractive approach for sustainable decarbonization. However, current electrodes with limited gas transport present a major barrier that hinders their practical implementation. Herein, porous polymeric electrodes are developed to effectively enhance CO2 transport without the need for additional gas diffusion conduits. Such all-in-one porous electrodes also enable more accessible redox active sites (e.g., quinones) for CO2 sorption, leading to an increased materials utilization efficiency of ≈90%. A continuous flow-through carbon capture and release operation with high Faradaic efficiency and excellent stability under practical working conditions is further demonstrated. Together with low cost and robust mechanical properties, the as-developed porous polymeric electrodes highlight the potential to advance the future implementation of electrochemical separation technologies.

Multi-scale imaging techniques to investigate solute transport across articular cartilage.

As articular cartilage is an avascular tissue, the transport of nutrients and cytokines through the tissue is essential for the health of cells, i.e. chondrocytes. Transport of specific contrast agents through cartilage has been investigated to elucidate cartilage quality. In laboratory, pre-clinical and clinical studies, imaging techniques such as magnetic imaging resonance (MRI), computed tomography (CT) and fluorescent microscopy have been widely employed to visualize and quantify solute transport in cartilage. Many parameters related to the physico-chemical properties of the solute, such as molecular weight, net charge and chemical structure, have a profound effect on the transport characteristics. Information on the interplay of the solute parameters with the imaging-dependent parameters (e.g. resolution, scan and acquisition time) could assist in selecting the most optimal imaging systems and data analysis tools in a specific experimental set up. Here, we provide a comprehensive review of various imaging systems to investigate solute transport properties in articular cartilage, by discussing their potentials and limitations. The presented information can serve as a guideline for applications in cartilage imaging and therapeutics delivery and to improve understanding of the set-up of solute transport experiments in articular cartilage.

Soil spreading of liquid olive mill processing wastes impacts leaching of adsorbed terbuthylazine.

Olive mill waste water (OMWW) is a major byproduct of the three phase olive oil production process. OMWW has high acidity (pH âˆ¼ 4-5), high salt content (EC âˆ¼ 5-10 mS cm(-1)), extremely high biological and chemical oxygen demand (BOD and COD up to 100,000 and 220,000 mg L(-1), respectively), and also high concentrations of organic compounds such as phenols and polyphenols. As a result, OMWW cannot be freely discharged into domestic wastewater treatment plants, but on-site treatment is very expensive and not sufficiently effective. Uses for OMWW such as agricultural recycling and co-composting were found to be impractical or expensive. Thus, OMWW is frequently spread on agricultural land for disposal. However, excessive or uncontrolled spreading of such organic-rich and saline wastewater could have many deleterious effects on soil quality, including salinization, phytotoxicity, or contaminant movement. The impact of OMWW on the leaching of adsorbed terbuthylazine, a soil-applied herbicide, was tested in four soils of varying physical and chemical properties. Although terbuthylazine solubility in OMWW is significantly higher than in water, leaching of adsorbed terbuthylazine from OMWW-treated soils was less than from control treatments. Low soil organic carbon and clay contents were major factors that contributed to reduced terbuthylazine leaching after soil treatment with OMWW.

Effect of bacteria on the transport and deposition of multi-walled carbon nanotubes in saturated porous media.

The influence of bacteria on the transport and deposition behaviors of carbon nanotubes (CNTs) in quartz sand was examined in both NaCl (5 and 25 mM ionic strength) and CaCl2 (0.3 and 1.2 mM ionic strength) solutions at unadjusted pH (5.6-5.8) by direct comparison of both breakthrough curves and retained profiles in both the presence and absence of bacteria. Two types of widely utilized CNTs, i.e., carboxyl- and hydroxyl-functionalized multi-walled carbon nanotubes (MWCNT-COOH and MWCNT-OH, respectively), were employed as model CNTs and Escherichia coli was utilized as the model bacterium. The results showed that, for both types of MWCNTs under all examined conditions, the breakthrough curves were higher in the presence of bacteria, while the retained profiles were lower, indicating that the co-presence of bacteria in suspension increased the transport and decreased the deposition of MWCNTs in porous media, regardless of ionic strength or ion valence. Complementary characterizations and extra column tests demonstrated that competition by bacteria for deposition sites on the quartz sand surfaces was a major (and possibly the sole) contributor to the enhanced MWCNTs transport in porous media.

Particle phase distribution of polycyclic aromatic hydrocarbons in stormwater--Using humic acid and iron nano-sized colloids as test particles.

The distribution of polycyclic aromatic hydrocarbons (PAHs) in different particulate fractions in stormwater: Total, Particulate, Filtrated, Colloidal and Dissolved fractions, were examined and compared to synthetic suspensions of humic acid colloids and iron nano-sized particles. The distribution of low-molecular weight PAHs (LMW PAHs), middle-molecular weight PAHs (MMW PAHs) and high-molecular weight PAHs (HMW PAHs) among the fractions was also evaluated. The results from the synthetic suspensions showed that the highest concentrations of the PAHs were found in the Filtrated fractions and, surprisingly, high loads were found in the Dissolved fractions. The PAHs identified in stormwater in the Particulate fractions and Dissolved fractions follow their hydrophobic properties. In most samples >50% of the HMW PAHs were found in the Particulate fractions, while the LMW and MMW PAHs were found to a higher extent in the Filtrated fractions. The highest concentrations of PAHs were present in the stormwater with the highest total suspended solids (TSS); the relative amount of the HMW PAHs was highest in the Particulate fractions (particles>0.7 µm). The highest concentration of PAHs in the Colloidal fraction was found in the sample with occurrence of small nano-sized particles (<10nm). The results show the importance of developing technologies that both can manage particulate matter and effectively remove PAHs present in the Colloidal and Dissolved fractions in stormwater.