BTES and aldehydes analysis in PET-bottled water in Lebanon

Fluorosensing of benzaldehydes by CuI-graphene: A spectroscopy, thermodynamics and docking supported phenomenon

Benzaldehyde and 4-methyl benzaldehyde constitute a major part of the harmful volatile organic compounds (VOCs) found in the environment. Hence, rapid and selective detection of benzaldehyde derivatives are required to minimize the environmental degradation as well as the potential hazards on human health. In this study, the surface of the graphene nanoplatelets were functionalized with CuI nanoparticles for specific and selective detection of benzaldehyde derivatives by fluorescence spectroscopy. CuI-Gr nanoparticles exhibited higher efficiency towards the detection of benzaldehyde derivatives as compared to pristine CuI nanoparticles with detection limit (LOD) 2 ppm and 6 ppm for benzaldehyde and 4-methyl benzaldehyde respectively in aqueous medium. The LOD values for the detection of benzaldehyde and 4-methyl benzaldehyde by pristine CuI nanoparticles were poor and found to be 11 ppm and 15 ppm respectively. Fluorescence intensity of CuI-Gr nanoparticles were found to be quenched with increasing concentration (0-0.01 mg/mL) of the benzaldehyde and 4-methyl benzaldehyde. This novel graphene-based sensor was also found to be highly selective for the benzaldehyde derivatives as no changes in signal were detected in presence of other VOCs like formaldehyde and acetaldehyde.

Effect of storage on the levels of phthalates in high-density polyethylene (HDPE) film-packaged drinking water

High-Density Polyethylene (HDPE)-packaged water is a popular choice for urban potable water across Africa. However, the sources and fate of priority chemical contaminants have not been adequately reported. The present study seeks to determine the effect of storage and labelling on the levels of phthalates - dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP), benzyl butyl phthalate (BBP) and di(2-hexylethyl) phthalate (DEHP) - in HDPE packaged water. Printed and unprinted 500 mL packet samples, treated water and raw water samples were collected from two major companies in Accra and stored at three temperature levels for 28 days. Phthalates were extracted and pre-concentrated for analysis by GC-MS weekly. The results indicated that phthalates loading became detectable within the first 7 days of incubation, with printed samples showing higher concentrations than unprinted samples at every incubation temperature. The highest concentration was recorded for BBP (1.03 μg/L between a lower and upper confidence limits of 0.62 μg/L and 1.42 μg/L). Temperature significantly affected the concentration of DMP for printed packets (p-value = 0.05) and unprinted samples (p-value = 0.06), BBP across all samples, and DEHP in printed samples (p-value = 0.06). On the other hand, storage duration significantly affected the concentration of BBP across all samples. There was a very strong correlation between printing and the concentration of phthalates in the water samples (p-values <0.001) across the storage temperatures. Effect size analysis established significant differences between site-specific printed and unprinted samples. The present study revealed weak interactions between the selected phthalates and the HDPE matrix, and recommends alternative packaging that can restrict the presence of phthalates and other priority chemicals in plastic packaged drinking water.

Evaluation of occurrence of organic, inorganic, and microbial contaminants in bottled drinking water and comparison with international guidelines: a worldwide review

The aim of this study was to evaluate the levels of inorganic and organic substances as well as microbial contaminants in bottled drinking water on a global scale. The findings were compared to WHO guidelines, EPA standards, European Union (EU) directive, and standards drafted by International Bottled Water Association (IBWA). Our review showed that 46% of studies focused on the organic contaminants, 25% on physicochemical parameters, 12% on trace elements, 7% on the microbial quality, and 10% on microplastics (MPs) and radionuclides elements. Overall, from the 54 studies focusing on organic contaminants (OCs) compounds, 11% of studies had higher OCs concentrations than the standard permissible limit. According to the obtained results from this review, several OCs, inorganic contaminants (IOCs), including CHCl₃, CHBrCl₂, DEHP, benzene, styrene, Ba, As, Hg, pb, Ag, F, NO₃, and SO₄ in bottled drinking water of some countries were higher than the international guidelines values that may cause risks for human health in a long period of time. Furthermore, some problematic contaminants with known or unknown health effects such as EDCs, DBP, AA, MPs, and some radionuclides (⁴⁰K and ²²²Rn) lack maximum permissible values in bottled drinking water as stipulated by international guidelines. The risk index (HI) for OCs and IOCs (CHBrCl₂, Ba, As, and Hg) was higher than 1 in adults and children, and the value of HI for CHCl₃ in children was more than 1. Thus, further studies are required to have a better understanding of all contaminants levels in bottled drinking water.

Characterization of VOCs and additives in Italian PET bottles and studies on potential functional aldehydes scavengers

This study focused on characterization of Volatile Organic Compounds (VOCs) as contaminants and non-volatile additives in Italian PET bottles, also suggesting potential functional aldehydes scavengers. Several VOCs, such as acetic aldehyde (AA), butanal, 3-methyl butanal, 1,3-dioxolane, pentanal, hexanal, octanal, 5-hepten-2-one, nonanal, and decanal, were identified by Head Space-Gas Chromatography/Mass Spectrometry (HS-GC/MS) in the PET bottles used for the packaging of six Italian brands mineral waters. AA, 1,3-dioxolane, octanal, 5-hepten-2-one, nonanal, and decanal were the most abundant compounds identified. These contaminants were also identified in the PET-bottled mineral waters. Different experiments using bottle-grade PET pellets (Btlg-PET) and PET bottles’ fragments with and without the addition of epoxidized soybean oil (ESBO) or erucamide as lubricant/plasticizer additives, poly(m-xylene adipamide) (MXD6), and/or anthranilamide (2-aminobenzamide) as potential aldehydes scavengers were carried out. Mostly VOCs observed in the PET bottles analysed were identified in a neat ESBO sample. The presence of the ESBO additive in the PET-bottle fragments was also observed by matrix-assisted laser desorption/ionization time of flight mass spectrometry analysis (MALDI–TOF MS). The ESBO sub-products were not observed in the virgin btlg-PET pellets analysed by both HS-GC/MS and MALDI–TOF MS. These results suggest that the VOCs come from an ESBO additive probably loaded during the blow-moulding processes used for the manufacturing of PET bottles. Further studies established that MXD6 (1%w), an efficient oxygen scavenger, could be also used as AA scavenger even in the presence of the commonly used anthranilamide.

Barriers and benefits to desired behaviors for single use plastic items in northeast Ohio's Lake Erie basin

Given the growing saliency of plastic marine debris, and the impact of plastics on beaches and aquatic environments in the Laurentian Great Lakes, applied research is needed to support municipal and nongovernmental campaigns to prevent debris from reaching the water's edge. This study addresses this need by examining the barriers and benefits to positive behavior for two plastic debris items in northeast Ohio's Lake Erie basin: plastic bags and plastic water bottles. An online survey is employed to gather data on the use and disposal of these plastic items and to solicit recommendations on how to positively change behavior to reduce improper disposal. Results support a ban on plastic bags and plastic water bottles, with more enthusiasm for a bag ban. Financial incentives are also seen as an effective way to influence behavior change, as are location-specific solutions focused on education and outreach.