Towards Microplastic Reduction Within Institutions.

Globally, universities, institutions, and companies are aiming to reduce the use of single-use plastics as plastic litter, and plastic degradation generates secondary microplastics, all of which cause negative impacts on the environment. In this study the authors conducted a questionnaire-based survey to assess the willingness and motivation of stakeholders within academic settings to change daily habits to minimize plastic and microplastic pollution. The questionnaire, which was answered by 276 individuals with affiliation to the American Farm School or collaborating academic institutions, but primarily the American Farm School, was used to draw conclusions. Results showed that most stakeholders are ready to adapt to eliminate the use of single-use plastic within their institution and showed a high level of willingness to participate in cleaning campaigns. It is crucial to combine any new measures or policies with the proper education around why these measures are being enforced, so as to raise awareness and receptivity to those that are not familiar with microplastics and microplastic pollution.

Anatomy of the atmospheric emissions from the transport sector in Greece: trends and challenges.

Emissions of atmospheric pollutants are well-known for their adverse effects on air quality and public health. Additionally, GHG emissions are responsible for the so called "Radiating Forcing" leading to climate change and degradation of ecosystem services. In this work, we analyze the annual emission trends of various air pollutants, including GHGs, from all 4 sectors of transport (roads, aviation, navigation, and railway) in Greece during the 28-year period between 1990 and 2017, in order to examine the confounding dynamics among external forces, such as the major fiscal recession of 2008, and the GHG/pollutant emissions in the country. The analysis is performed with a suite of statistical tools consisting of bivariate correlation analysis, Mann-Kendall test, Sen's slope estimation, and Joinpoint regression analysis, in order to thoroughly study the trends of emissions. It is found that all transport sectors (except for the railway) show a significant increase in their emissions, despite the fiscal recession of 2008 that temporarily decelerated all aspects of economic activity in the country. Given the major share of transport in GHG emissions (37%) and air pollution in urban centers, it is essential that the road sector adapts to the new challenges, by means of switching to low-emission technologies and electromobilization. The same applies for the navigation and aviation sectors, which are known pillars of the tourist industry in the country.

Properties and Performance of Novel Mg(OH)2-Based Coatings for Corrosion Mitigation in Concrete Sewer Pipes.

The biological activity occurring in urban sewerage systems usually leads to the (biogenic) corrosion of pipe infrastructure. Anti-corrosion coating technology was developed in an effort to protect sewer pipes from degradation. This study evaluates a new class of relatively low-cost magnesium hydroxide-based coatings, regarding their ability to adhere efficiently onto the concrete surface, and offer efficient corrosion protection. Six magnesium hydroxide-based coatings were prepared with the addition of two different types of cellulose, used as adhesion additives, and these were applied on concrete specimens. Pull-off measurements showed that the addition of higher amounts of cellulose could improve the coating adhesion onto the concrete surface. An accelerated sulfuric acid spraying test was used to evaluate the consumption time of the applied coatings and their efficiency in maintaining over time slightly alkaline pH values (above 8) on the coated/protected surfaces. At the end of spraying test, a mineralogical analysis of surface samples was performed, indicating that the formation of corrosion by-products (mainly gypsum) was increased when the added amount of cellulose was lower. Hardness and roughness measurements were also conducted on the concrete surfaces, revealing that the coatings helped the concrete surface to preserve its initial surface properties, in comparison to the uncoated specimens. A SEM/microstructure analysis showed that aggregates were formed (possibly consisting of Mg(OH)2), affecting the reactivity of the protected surface against sulfuric acid attack.

Combined Effect of Colloids and SMP on Membrane Fouling in MBRs.

Membrane fouling investigations in membrane bioreactors (MBRs) are a top research issue. The aim of this work is to study the combined effect of colloids and soluble microbial products (SMPs) on membrane fouling. Two lab-pilot MBRs were investigated for treating two types of wastewater (wwt), synthetic and domestic. Transmembrane pressure (TMP), SMP, particle size distribution and treatment efficiency were evaluated. Chemical Oxygen Demand (COD) removal and nitrification were successful for both kinds of sewage reaching up to 95-97% and 100%, respectively. Domestic wwt presented 5.5 times more SMP proteins and 11 times more SMP carbohydrates compared to the synthetic one. In contrast, synthetic wwt had around 20% more colloids in the mixed liquor with a size lower than membrane pore size (<400 nm) than domestic. Finally, the TMP at 36 days reached 16 kPa for synthetic wwt and 11 kPa for domestic. Therefore, synthetic wwt, despite its low concentration of SMPs, caused severe membrane fouling compared to domestic, a result that is attributed to the increased concentration of colloids. Consequently, the quantity of colloids and possibly their special characteristics play decisive and more important roles in membrane fouling compared to the SMP-a novel conclusion that can be used to mitigate membranes fouling.

Polystyrene Magnetic Nanocomposites as Antibiotic Adsorbents.

There are different ways for antibiotics to enter the aquatic environment, with wastewater treatment plants (WWTP) considered to be one of the main points of entrance. Even treated wastewater effluent can contain antibiotics, since WWTP cannot eliminate the presence of antibiotics. Therefore, adsorption can be a sustainable option, compared to other tertiary treatments. In this direction, a versatile synthesis of poly(styrene-block-acrylic acid) diblock copolymer/Fe3O4 magnetic nanocomposite (abbreviated as P(St-b-AAc)/Fe3O4)) was achieved for environmental applications, and particularly for the removal of antibiotic compounds. For this reason, the synthesis of the P(St-b-AAc) diblock copolymer was conducted with a reversible addition fragmentation transfer (RAFT) method. Monodisperse superparamagnetic nanocomposite with carboxylic acid groups of acrylic acid was adsorbed on the surface of Fe3O4 nanoparticles. The nanocomposites were characterized with scanning electron microscopy (SEM), X-ray diffraction (XRD) and vibrating sample magnetometer (VSM) analysis. Then, the nanoparticles were applied to remove ciprofloxacin (antibiotic drug compound) from aqueous solutions. The effects of various parameters, such as initial drug concentration, solution pH, adsorbent dosage, and contact time on the process were extensively studied. Operational parameters and their efficacy in the removal of Ciprofloxacin were studied. Kinetic and adsorption isothermal studies were also carried out. The maximum removal efficiency of ciprofloxacin (97.5%) was found at an initial concentration of 5 mg/L, pH 7, adsorbent's dosage 2 mg/L, contact time equal to 37.5 min. The initial concentration of antibiotic and the dose of the adsorbent presented the highest impact on efficiency. The adsorption of ciprofloxacin was better fitted to Langmuir isotherm (R2 = 0.9995), while the kinetics were better fitted to second-order kinetic equation (R2 = 0.9973).

Nanomaterials in Cosmetics: Recent Updates.

This review paper collects the recent updates regarding the use of nanomaterials in cosmetics. Special focus is given to the applications of nanomaterials in the cosmetic industry, their unique features, as well as the advantages of nanoscale ingredients compared to non-nanoscale products. The state-of-the-art practices for physicochemical and toxicological characterization of nanomaterials are also reviewed. Moreover, special focus is given to the current regulations and safety assessments that are currently in place regarding the use of nanomaterials in cosmetics-the new 2019 European guidance for the safety assessment of nanomaterials in cosmetics, together with the new proposed methodologies for the toxicity evaluation of nanomaterials. Concerns over health risks have limited the further incorporation of nanomaterials in cosmetics, and since new nanomaterials may be used in the future by the cosmetic industry, a detailed characterization and risk assessment are needed to fulfill the standard safety requirements.