•Monitoring occurrence and fate of perfluorinated compounds in the aqueous environment.•Industrial wastes are the main source of contamination in a highly industrialized urban area.•Perfluorinated ...substances were not removed in sewage treatment plants.•Surface water contamination was increasing from north to south in the Lambro river basin.•Ground and drinking water were also contaminated in industrial areas.
Perfluorinated substances are listed among emerging contaminants because they are globally distributed, environmentally persistent, bioaccumulative and potentially harmful. In a three-year monitoring campaign (2010–2013) we investigated the occurrence, sources and fate of nine perfluoroalkylcarboxylic acids and three perfluoroalkylsulfonic acids, in the most industrialized region of Italy. Composite samples were collected in influents and effluents of wastewater treatment plants (WWTPs), in the main rivers flowing through the basin, and in raw groundwater and finished drinking water. Samples were analyzed by liquid chromatography tandem mass spectrometry. Perfluorinated substances were not removed in WWTPs and those receiving industrial wastes discharged up to 50 times the loads of WWTPs receiving municipal wastes. The mass balance of the emissions in the River Lambro basin showed continuously increasing contamination from north to south and differences in the composition of homologues in the west and east sides of the basin. Ground and drinking water were contaminated in industrial areas, but these substances were removed well in Milan. Contamination from industrial sources was prevalent over urban sources, contributing to 90% of the loads measured at the closure of the basin. The River Lambro was confirmed as one of the main sources of contamination in the Po River.
Deoxynivalenol (DON) and zearalenone (ZEN) pose a serious threat to human health, and have been frequently detected in the aqueous environment. To protect consumers from the harm of mycotoxins, a ...nanozyme-mediated multiplexed lateral flow immunoassay (LFIA) integrated with a smartphone was developed for rapid, highly sensitive and simultaneous quantitative detection of DON and ZEN in the aqueous environment. Highly efficient peroxidase mimicking core-shell Au@Pt nanozymes were synthesized by one-pot method, and then used as signal amplification to highly improve sensitivity of the detection, while a smartphone-based quantitative detection device could rapidly quantify results to improve the detection efficiency of the LIFA for on-site detection. After optimization, the detection time of the assay was 10 min, and the detection limits of the LIFA for DON/ZEN were 0.24/0.04 ng/mL, which were improved 416 and 150 folds compared to the conventional gold nanoparticles (GNPs)-based LFIA. Moreover, there was no obvious cross-reaction with other related mycotoxins, indicating that LFIA had a high specificity. The average recoveries of DON and ZEN from corn, wheat and three water samples were obtained from 94.3 % to 107.9 % with relative standard deviations of 0.2–7.6 %. Furthermore, the accuracy and reliability of the LIFA were evaluated with three spiked water samples, and the results presented good correlations with analytic results from the enzyme-linked immunosorbent assay (R2 =0.988 for DON, and 0.983 for ZEN). The results indicate the proposed LIFA was potentially a rapid, on-site simultaneous and highly sensitive method for DON and ZEN detection in the aqueous environment.
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•An efficient detection method was established for deoxynivalenol and zearalenone in the aqueous environment.•The self-developed quantitative detection equipment can realize the on-site quantitative detection of mycotoxins.•The Au@Pt/AEC-based LFIA can significantly improve detection sensitivity compared to the conventional GNPs-based LFIA.
Abstract
A growing demand in polylactic acid (PLA) has increased in recent years due to the increasing of non-degradable plastic wastes. The recycling of PLA waste is seen to be another permissible ...solution to conserve the resources. This work aims to study the degradation rate of virgin PLA (VPLA) and recycled PLA (RPLA) in terms of the mechanical properties after ageing in different aqueous environment. The samples were immersed in river water (RW) and seawater (SW) for the duration of 150 days. Tensile strength, transverse rupture strength (TRS), impact energy and hardness properties were investigated as a function of immersed time. The results revealed that the loss in the tensile strength accelerated in river water when compared to seawater. There was at least 50% of tensile strength sacrificed in recycled PLA. The TRS had dropped approximately half from its initial value after ageing in river water and about 30% after ageing in seawater. Besides, a huge decrease ranging around 70-80% from its initial impact energy was identified. However, the reduction in hardness was relatively low. The findings will help to elucidate the degradation process of PLA and the desired effect on the mechanical performance for further application.
Phenol is classified as one of the environmental pollutants and is found in the wastewaters of various industries such as petroleum industry, paint and chemical industries, oil refining and textile ...industries. High concentrations of this substance are harmful to human health and can cause adverse cardiac and neurological effects. Therefore, it seems necessary to eliminate this material from industrial wastewater, although their elimination requires the use of new methods. In this regard, in this work, two-dimensional adsorbents have been used to remove phenol from the aqueous environment. To do this, the ability to simulate molecular dynamics in investigating the interactions of phenol molecules and 4 transition metal dichalcogenides (TMDs)v Used. CdS2 had the largest level of interaction with phenol molecules and had the greatest effect in removing phenol from the aqueous environment. The results obtained from this work have provided new materials to remove phenol from the wastewater petroleum industry and can facilitate the widespread use of these materials in industrial petroleum wastewater treatment.
Here, we demonstrate a diffraction-free Bloch surface wave sustained on all-dielectric multilayers that does not diffract after being passed through three obstacles or across a single mode fiber. It ...can propagate in a straight line for distances longer than 110 μm at a wavelength of 633 nm and could be applied as an in-plane optical virtual probe both in air and in an aqueous environment. Its ability to be used in water, its long diffraction-free distance, and its tolerance to multiple obstacles make this wave ideal for certain applications in areas such as the biological sciences, where many measurements are made on glass surfaces or for which an aqueous environment is required, and for high-speed interconnections between chips, where low loss is necessary.
•Long-term creep of bio-based concrete in aqueous environment is investigated.•Creep strain of bio-based concrete decreases with the increase of water pressure.•A modified Burgers piecewise model for ...bio-based concrete is proposed.
Bio-based materials generally have high porosity, which are prone to biodegradation during the long-term application, especially in a humid environment. To better understand the impact of the aqueous environment on creep performance of bio-based concrete, the effects of the loading method (single-stage and multi-stage), axial force (50 kN, 100 kN, 150 kN), and water pressure (1 MPa, 2 MPa, 3 MPa) on the long-term creep characteristics of bio-based apricot shell concrete are investigated in this study, with a creep duration of up to 1051 h. The results show that water pressure has a significant effect on the creep properties of apricot shell concrete. The creep strain and creep rate of apricot shell concrete gradually decrease with the increase of water pressure, which attributes to the water confining pressure that restrains the propagation of micro-cracks and consequently reduces the creep strain. Moreover, the creep strain and creep rate of apricot shell concrete increase with the increase of axial force. The creep behavior of bio-based apricot shell concrete in low load level is well described by a proposed Burgers piecewise creep model, which is recommended to express the long-term creep behavior of bio-based apricot shell concrete in the aqueous environment.
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