Carrageenan/calcium alginate composite hydrogel filtration membranes for efficient cationic dye separation.

The development of biopolymer-based filtration systems for water remediation applications is an extremely fascinating area of research. In this paper, we developed a biopolymer-based filtration system using sodium alginate (NaAlg) and carrageenan (Car) for the removal of the toxic cationic dye, methylene blue (MB). The membrane's properties were assessed using FTIR, TGA, UTM, FESEM, EDS, XRD, and water uptake, revealing commendable thermomechanical stability (5.79 MPa), good hydrophilicity, and compatibility. The experimental results further revealed that lambda Car/calcium alginate (λ-Car/CaAlg) exhibited superior dye rejection (100%) and flux (11.67 L m-2 h-1) compared to kappa Car/CaAlg (κ-Car/CaAlg) (99.22% and 11.19 L m-2 h-1) and plain alginate (CaAlg) (99.63% and 9.79 L m-2 h-1). The high MB rejection rate was attributed to the sieving mechanism and electrostatic interaction. A rejection rate of 100% was achieved at an initial MB concentration of 10 mg/L, pressure of 0.1 MPa, pH of 7, and temperature of 25°C. Furthermore, the hydrogel membranes demonstrated excellent recyclability over nine cycles, indicating their potential for water treatment applications.

Decoration of dandelion-like manganese-doped iron oxide microflowers on plasma-treated biochar for alleviation of heavy metal pollution in water.

Carbon-based biowaste incorporated with inorganic oxides as a composite is an enticing option to mitigate heavy metal pollution in water resources due to its more economical and efficient performance. With this in mind, we constructed manganese-doped iron oxide microflowers resembling the dandelion-like structure on the surface of cold plasma-treated carbonized rice husk (MnFe2O3/PCRH). The prepared composite exhibited 45% and 19% higher removal rates for Cu2+ and Cd2+, respectively than the pristine CRH. The MnFe2O3/PCRH composite was characterized using XRD, FTIR, FESEM, EDX, HR-TEM, XPS, BET, TGA, and zeta potential, while the adsorption capacities were investigated as a function of pH, time, and initial concentration in batch trials. As for the kinetics, the pseudo-second-order was the rate-limiting over the pseudo-first-order and Elovich model, demonstrating that the chemisorption process governed the adsorption of Cu2+ and Cd2+. Additionally, the maximum adsorption capacities of the MnFe2O3/PCRH were found to be 122.8 and 102.5 mg/g for Cu2+ and Cd2+, respectively. Based on thorough examinations by FESEM-EDS, FTIR, and XPS, the possible mechanisms for the adsorption can be ascribed to surface complexation by oxygen-containing groups, a dissolution-precipitation of the ions with -OH groups, electrostatic attraction between metal ions and the adsorbent's partially charged surface, coordination of Cu2+ and Cd2+ with π electrons by aromatic/graphitic carbon in the MnFe2O3/PCRH, and pore filling and diffusion. Lastly, the adsorption efficiencies were maintained at about 70% of its initial adsorption even after five adsorption-desorption cycles, displaying its remarkable stability and reusability.

Feasibility evaluation of near dissolved organic matter microfiltration (NDOM MF) for the efficient removal of microplastics in the water treatment process.

Microfiltration (MF) using membranes with a mean pore size smaller than 0.45 µm has generally been used for particle removal from water, given that materials larger and smaller than 0.45 µm are regarded as particulates and dissolved organic matter (DOM), respectively. It is also the case for removing small-size microplastics (MPs). However, given their sizes (ca. 1 µm), there is room for further improvement of the productivity (i.e., water flux) in the pore size range of 0.45-1 µm on the condition that the removal rate is maintained. With this in mind, MF's water flux and removal rate were tested using seven different MF membranes, and the right pore, with the size of 0.8 µm, was found for MP removal, which is called near DOM (NDOM) MF. In the filtration test using polystyrene surrogate beads with an average particle diameter of 1.20 µm, NDOM MF exhibited a 1.7 to 13 times higher permeate flux than the conventional MF using 0.1, 0.2, and 0.45 µm membranes while maintaining a higher removal rate than 2 log. The excellent removal rate of the NDOM MF was attributable to the following three factors: (1) smaller mean pore size than the average particle diameter, (2) particle screening effect enhanced by the secondary layer formed by surface deposition, and (3) 3D mesh sublayer structure favorable for capturing penetrated particles. Furthermore, the outstanding filtration performance also appeared in a low-temperature (< 10°C) process, demonstrating that NDOM MF is feasible independently of temperature. Additionally, in constant flux filtration, NDOM MF demonstrated the long-term feasibility by lowering the transmembrane pressure and specific filtration energy by more than 2 times.

Protecting and Utilizing Health and Medical Big Data: Policy Perspectives from Korea.

OBJECTIVES: We analyzed Korea's data privacy regime in the context of protecting and utilizing health and medical big data and tried to draw policy implications from the analyses. METHODS: We conducted comparative analyses of the legal and regulatory environments governing health and medical big data with a view to drawing policy implications for Korea. The legal and regulatory regimes considered include the following: the European Union, the United Kingdom, France, the United States, and Japan. We reviewed relevant statutory materials as well as various non-statutory materials and guidelines issued by public authorities. Where available, we also examined policy measures implemented by government agencies. RESULTS: In this study, we investigated how various jurisdictions deal with legal and regulatory issues that may arise from the use of health and medical information with regard to the protection of data subjects' rights and the protection of personal information. We compared and analyzed various forms of legislation in various jurisdictions and also considered technical methods, such as de-identification. The main findings include the following: there is a need to streamline the relationship between the general data privacy regime and the regulatory regime governing health and medical big data; the regulatory and institutional structure for data governance should be more clearly delineated; and regulation should encourage the development of suitable methodologies for the de-identification of data and, in doing so, a principle-based and risk-based approach should be taken. CONCLUSIONS: Following our comparative legal analyses, implications were drawn. The main conclusion is that the relationship between the legal requirements imposed for purposes of personal information protection and the regulatory requirements governing the use of health and medical data is complicated and multi-faceted and, as such, their relationship should be more clearly streamlined and delineated.