ZnO nanostructured matrix as nexus catalysts for the removal of emerging pollutants.

Water pollution stands as a pressing global environmental concern, elevating the significance of innovative, dependable, and sustainable solutions. This study represents an extensive review of the use of photocatalytic zinc oxide nanoparticles (ZnO NPs) for the removal of emerging pollutants from water and wastewater. The study examines ZnO NPs' different preparation methods, including physical, chemical, and green synthesis, and emphasizes on advantages, disadvantages, preparation factors, and investigation methods for the structural and morphological properties. ZnO NPs demonstrate remarkable properties as photocatalysts; however, their small dimensions pose an issue, leading to potential post-use environmental losses. A strategy to overcome this challenge is scaling up ZnO NP matrices for enhanced stability and efficiency. The paper introduces novel ZnO NP composites, by incorporating supports like carbon and clay that serve as photocatalysts in the removal of emerging pollutants from water and wastewater. In essence, this research underscores the urgency of finding innovative, efficient, and eco-friendly solutions for the removal of emerging pollutants from wastewater and highlights the high removal efficiencies obtained when using ZnO NPs obtained from green synthesis as a photocatalyst. Future research should be developed on the cost-benefit analysis regarding the preparation methods, treatment processes, and value-added product regeneration efficiency.

Ferrous Industrial Wastes-Valuable Resources for Water and Wastewater Decontamination.

Ferrous waste by-products from the metallurgical industry have a high potential for valorization in the context of the circular economy, and can be converted to value-added products used in environmental remediation. This research reviews the latest data available in the literature with a focus on: (i) sources from which these types of iron-based wastes originate; (ii) the types of ferrous compounds that result from different industries; (iii) the different methods (with respect to the circular economy) used to convert them into products applied in water and wastewater decontamination; (iv) the harmful effects ferrous wastes can have on the environment and human health; and (v) the future perspectives for these types of waste.

Walnut Shell Biowaste Valorization via HTC Process for the Removal of Some Emerging Pharmaceutical Pollutants from Aqueous Solutions.

This research emphasizes the performance of some eco-friendly carbon materials as hydrochars (HC) obtained by the hydrothermal carbonization (HTC) process applied to walnut shell (WS) biowaste. These materials display promising properties that can be used for environmental applications such as emerging pharmaceutical pollutant retention from water sources. Thus, three hydrochars coded HCWS1, HCWS2, and HCWS3 were obtained using a dynamic autoclave in specific conditions-temperature of 220 °C, autogenous pressure, 1:10 biomass-water weight ratio-and for three different reaction times, 1 h, 6 h, and 12 h. The HCWSs were characterized by means of ATR-FTIR and SEM-EDS analyses and tested as possible adsorbents to assess the removal efficiencies of some emerging pharmaceutical pollutants (paracetamol and methylene blue) by UV-VIS spectrophotometry. Kinetic and adsorption studies were carried out. The best results were obtained for the HCWS3 hydrochar. Further perspectives include an activation step of the hydrochars and their testing on other emerging pharmaceutical pollutants.

Adsorption of Copper (II) from Aqueous Solutions with Alginate/Clay Hybrid Materials.

Massive amounts of industrial and agricultural water around the world are polluted by various types of contaminants that harm the environment and affect human health. Alginic acid is a very versatile green polymer used for heavy metal adsorption due to its availability, biocompatibility, low cost, and non-toxic characteristics. The aim of this paper was to prepare new low-cost hybrid composite beads using sodium alginate with treated montmorillonite and kaolin for the adsorption of copper (Cu) cations. Modified and unmodified clays were investigated by studying their morphology and elemental composition, functional groups, and mean particle size and particle size distribution. The characterization of alginate/clay hybrid composite beads was carried out by evaluating surface morphology (by scanning electron microscopy, SEM), crystallinity (by X-ray diffraction, XRD), and point of zero charge (pHpzc)(Zeta Potential Analyzer). Batch adsorption experiments of alginate/clay hybrid composite beads investigated the effect of metal concentration in the range of 1-4 mg L-1 on Cu(II) removal, adsorption kinetic for maximum 240 min, and Langmuir and Freundlich adsorption isotherms by using atomic absorption spectrometry. The pseudo-second-order kinetic model best fitted the adsorption for alginate/montmorillonite beads (R2 = 0.994), while the diffusion process was predominant for montmorillonite/kaolin beads (R2 = 0.985). The alginate/clay hybrid materials best fitted the Langmuir isotherm model.

Novel Adsorbent Based on Banana Peel Waste for Removal of Heavy Metal Ions from Synthetic Solutions.

Due to its valuable compounds, food waste has been gaining attention in different applications, such as life quality and environment. Combined with circular economy requirements, a valorization method for waste, especially banana waste, was to convert them into adsorbents with advanced properties. The banana waste, after thermal treatment, was used with high removal performances (100%) for the removal of heavy metals, such as Cr, Cu, Pb, and Zn, but their small particle size makes them very hard to recover and reuse. For this reason, a biopolymeric matrix was used to incorporate the banana waste. The matrix was chosen for its remarkable properties, such as low cost, biodegradability, low carbon footprint, and reduced environmental impact. In this research, different types of materials (simple banana peel ash BPA and combined with biopolymeric matrix, ALG-BPA, CS-BPA) were prepared, characterized, and tested. The materials were characterized by means of attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), optical microscopy (OM), scanning electron microscopy (SEM), and tested for the removal of metal ions from synthetic solutions using atomic absorption spectroscopy (AAS). The ALG-BPA material proved to be the most efficient in the removal of heavy metal ions from synthetic solution, reaching even 100% metal removal for Cr, Fe, Pb, and Zn, while the CS-based materials were the least efficient, presenting the best values for Cr and Fe ions with a removal efficiency of 34.14% and 28.38%, respectively. By adding BPA to CS, the adsorption properties of the material were slightly improved, but also only for Cr and Fe ions, to 37.09% and 57.78%.

Sustainable Rabbit Skin Glue to Produce Bioactive Nanofibers for Nonactive Wound Dressings.

This paper assessed the collagen glue (Col) from rabbit skin for use as a raw material in combination with different water-based dispersants of antimicrobial agents such as ZnO NPs, TiO2 NPs doped with nitrogen and Ag NPs (TiO2-N-Ag NPs), and chitosan (CS) for the production of biocompatible and antimicrobial nanofibers. The electrospun nanofibers were investigated by scanning electron microscopy (SEM), attenuated total reflectance in conjunction with Fourier-transform infrared spectroscopy (ATR-FT-IR) analyses and antioxidant activity. The biocompatibility of electrospun nanofibers was investigated on cell lines of mouse fibroblast NCTC ((clone L929) using MTT test assays. Antimicrobial activity was performed against Escherichia coli and Staphylococcus aureus bacteria and Candida albicans pathogenic fungus. Electrospun antimicrobial nanofibers based on collagen glue achieved reduction in the number of viable microorganisms against both fungi and bacteria and exhibited multiple inhibitory actions of fungal and bacterial strains. The electrospun nanofibers showed average dimension sizes in the range of 30-160 nm. The results indicated that both Col/TiO2-N-Ag NPs and Col/CS formulations are suitable for cell proliferation and may be useful for producing of nonactive wound dressings.

Effect of Styrene-Diene Block Copolymers and Glass Bubbles on the Post-Consumer Recycled Polypropylene Properties.

The recycled polypropylene (rPP) materials that meet technical requirements such as reducing the dimensions and improving the tensile, elongation, impact strength, thermal stability, as well as melt processing, are required for the manufacturing industry. In this paper, we studied the mechanical and thermal properties of post-consumer rPP by adding both synthesized thermoplastic elastomers, and glass bubbles (GB) by a melt allowing process. Styrene-butadiene (SBS) and styrene-isoprene (SIS) block-copolymers that had a styrene content of 30 wt% were synthesized by anionic sequential polymerization. The obtained post-consumer rPP composites were characterized by optical microscopy, scanning electron microscopy (SEM), mechanical analyses (tensile, density, hardness, VICAT softening temperature (VST), heat deflection temperature (HDT), dynamic mechanical analysis (DMA), IZOD strength) and thermal analyses (differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA)). Weight reduction and improvement of the tensile, elongation, impact strength, thermal stability, as well as melt processing of post-consumer recycled polypropylene (rPP) properties compounded with thermoplastic elastomers and glass bubbles, sustain the use of these formulations for engineering applications.

Eliminating missing race/ethnicity data from a sexually transmitted disease case registry.

Data regarding race and ethnicity are usually requested when conducting public health surveillance. However, such data are frequently not included in case reports by providers. This report describes efforts to reduce the extent of missing race and/or ethnicity data in reports of sexually transmitted diseases in Massachusetts. A list of cases reported to the Department of Public Health between March 1 and May 31 1999 lacking race and/or ethnicity data was generated. A student intern tried contacting the providers with a request for complete information. Of the 2,954 cases of syphilis, gonorrhea, and chlamydia infection reported during the study period, 34.8% (1,028 cases) lacked race/ethnicity data. Despite an average of 2.27 calls and 1.5 transfers per call, data was successfully added to only 143 cases, increasing the percent of reported cases with complete data from 65.2% to 70.0%. The telephone calls, while inefficient for collecting this data, had some advantages. For example, they offered opportunities for communication between the STD Division and providers regarding other provider needs or services that the Division might meet. Consideration can also be given to using surnmame lists, ethnic marketing lists, birth records, and matching the case's address with census block data to infer race and/or ethnicity.