Advances in Water, Air and Soil Pollution Monitoring, Modeling and Restoration.

Global pollution demands continuous attention and concerted efforts to reduce its effects [...].

Statistical Assessment, Modeling, and Mitigation of Water and Soil Pollution.

Nowadays, ambient air pollution levels and trends have become a topic of interest worldwide because primary atmospheric pollutants (APPs) are risk factors for the population and ecosystems [...].

A Real-Life Reproducibility Assessment for NMR Metabolomics.

Nuclear magnetic resonance (NMR) metabolomics is currently popular enough to attract both specialized and non-specialized NMR groups involving both analytical trained personnel and newcomers, including undergraduate students. Recent interlaboratory studies performed by established NMR metabolomics groups demonstrated high reproducibility of the state-of-the-art NMR equipment and SOPs. There is, however, no assessment of NMR reproducibility when mixing both analytical experts and newcomers. An interlaboratory assessment of NMR quantitation reproducibility was performed using two NMR instruments belonging to different laboratories and involving several operators with different backgrounds and metabolomics expertise for the purpose of assessing the limiting factors for data reproducibility in a multipurpose NMR environment. The variability induced by the operator, automatic pipettes, NMR tubes and NMR instruments was evaluated in order to assess the limiting factors for quantitation reproducibility. The results estimated the expected reproducibility data in a real-life multipurpose NMR laboratory to a maximum 4% variability, demonstrating that the current NMR equipment and SOPs may compensate some of the operator-induced variability.

Assessing the Water Pollution of the Brahmaputra River Using Water Quality Indexes.

Water quality is continuously affected by anthropogenic and environmental conditions. A significant issue of the Indian rivers is the massive water pollution, leading to the spreading of different diseases due to its daily use. Therefore, this study investigates three aspects. The first one is testing the hypothesis of the existence of a monotonic trend of the series of eight water parameters of the Brahmaputra River recorded for 17 years at ten hydrological stations. When this hypothesis was rejected, a loess trend was fitted. The second aspect is to assess the water quality using three indicators (WQI)-CCME WQI, British Colombia, and a weighted index. The third aspect is to group the years and the stations in clusters used to determine the regional (spatial) and temporal trend of the WQI series, utilizing a new algorithm. A statistical analysis does not reject the hypothesis of a monotonic trend presence for the spatially distributed data but not for the temporal ones. Hierarchical clustering based on the computed WQIs detected two clusters for the spatially distributed data and two for the temporal-distributed data. The procedure proposed for determining the WQI temporal and regional evolution provided good results in terms of mean absolute error, root mean squared error (RMSE), and mean absolute percentage error (MAPE).

Statistical methods for assessing water quality after treatment on a sequencing batch reactor.

Given that water scarcity is a big issue nowadays, wastewater treatment is necessary for the future water use and the prevention of environmental contamination. In this context, this study presents the results of the statistical analysis of ten water parameters before and after the water cleaning in a wastewater treatment plant (WWTP). The influent biodegradability is assessed by computing the BOD5/COD ratio. New momentary and global efficiency indices are introduced for the evaluation of the pollutants' removal efficiency. Five classes of efficiencies (excellent, good, fair, marginal, and poor) are also proposed for the evaluation of WWTP's performances. The study shows that the WWTP's efficiency is good - when working with six water parameters - and marginal - when working with ten parameters. Small efficiencies of nitrates, total dissolved solids, and chlorine removal are noticed. Statistical distributions of ten water parameters in the influent and effluent are fitted and tested by the Kolmogorov-Smirnov and Chi-squared tests. They are utilized for computing the probability of exceeding the admissible limits of water parameters in the effluent, which can be used as a warning tool for improving the WWTP's performance.

Modeling the carbon monoxide dissipation in Timisoara, Romania.

Modeling the evolution of pollutants' concentration is important for predicting their impact on the human health and implementing measures for a sustainable development and environmental protection. Since the carbon dioxide (CO) is one of the main pollutants that affect the urban environment, the present study aimed at building a model for the evolution of the mean daily and monthly concentration in Timisoara, Romania. We found a non-linear direct dependence of CO concentration on the temperature and humidity and an inverse proportional relationship with the wind speed. The models have been linearized and validated by statistical tests. The extreme values distributions have also been detected, and comparisons of the data with the admissible values are provided.

Mathematical modeling of sulfur dioxide concentration in the western part of Romania.

Nowadays air pollution is a major issue, due to its effect on the human health and environment. Therefore, in this article, we analyze the evolution of sulfur dioxide (SO2) concentration for eight months (November 2015-June 2016) at three monitoring stations in Timisoara, Romania. The results indicate that the legal limits have been exceeded only a few times and the pollutants' distribution is strongly influenced by the relative atmospheric calm in the County. We also propose a new model for the SO2 dissipation, which takes into account the individual data series, as well as the specific atmospheric conditions.

Bioengineering of stainless steel surface by covalent immobilization of enzymes. Physical characterization and interfacial enzymatic activity.

Two hydrolytic enzymes, namely lysozyme and trypsin, were covalently immobilized onto stainless steel surfaces using wet chemistry processes. The immobilization strategy took advantage of the spontaneous physisorption of the polymer poly(ethylene imine) (PEI) onto stainless steel to yield a firmly attached, thin organic layer containing a high density of primary amine functions. Both enzymes were then covalently grafted to the surface via a glutaraldehyde cross-linker. Alternatively, a thicker underlayer of PEI was chemisorbed by cross-linking two PEI layers by glutaraldehyde. The effective presence of both enzymes on the stainless steel surfaces and their relative amount were assessed by immunochemical assays employing specific anti-enzyme antibodies. Eventually, the hydrolytic activity of the immobilized enzymes was evaluated by local enzymatic tests with suitable substrates. This work demonstrates that, although the amount of enzymes did not vary significantly with the underlayer thickness, their hydrolytic activity could be much improved by increasing the distance from the oxide surface and, likely, by favoring their accessibility. Our data suggest that the immobilization of enzymes on solid oxide surfaces is feasible and efficient, and that the enzymes retain catalytic activity. It may thus provide a promising route towards biofilm-resistant materials.

Physico-chemical characterisation of lipids from Mytilus galloprovincialis (L.) and Rapana venosa and their healing properties on skin burns.

Black Sea molluscs and gastropods are the most studied organisms from the Romanian littoral zone. In particular, those from the Mytilidae species are of great interest because biochemical investigations have shown that they can be sources of biological active substances which can have different applications (e.g. food additives). We report here the extraction of lipids from two different species of molluscs (Mytilus galloprovincialis L., Mediterranean mussel) and gastropods (Rapana venosa, hard-shell clam). The extracts were evaluated in terms of antioxidant and composition properties and their healing properties were tested on skin burns in Wistar rats. Our studies proved that the two lipid extracts contained a relatively complex distribution of compounds, in terms of characteristic indices, polyunsaturated fatty acids (PUFA) and vitamins E and D. The presence of such compounds rendered the extracts very efficient in healing induced skin burns in Wistar rats. The histological analysis showed a reduction in the time of healing (12-13 and 13-15 days for the Mytilus galloprovincialis (L.) Rapana venosa extracts, respectively) compared to 20-22 for untreated animals, based on results from tissues and blood samples. Our investigations have been proved to be promising in terms of future potential applications of the extracts as skin-care products, cosmetics and/or pharmaceutical preparations owing to their dermorestitutive properties.

Covalent immobilization of lysozyme on stainless steel. Interface spectroscopic characterization and measurement of enzymatic activity.

A new strategy aiming at the protection of metallic surfaces against the growth of biofilms is presented here. This work reports the grafting of primary amines by aminosilanization of oxidized stainless steel followed by chemical coupling of the glycosidase lysozyme from hen egg white using glutaraldehyde as homobifunctional cross-linking agent. Controlled characterization of a stainless steel surface by X-ray photoelectron spectroscopy and Fourier transform infrared reflection-absorption spectroscopy at each step enabled the mode of binding, coverage, and orientation of the grafted molecules to be addressed. As a result, the stainless steel samples covered with a covalently immobilized layer of lysozyme showed some lytic activity on a suspension of bacteria Micrococcus lysodeikticus.