Characterizing the photodegradation-induced release of volatile organic compounds from bottled water containers

While plastic water bottles are known to potentially release various volatile organic compounds (VOCs) when exposed to light, existing knowledge in this field remains limited. In this study, we systematically examined the composition, yield, and toxicity of VOCs released from six plastic containers obtained from different continents under UV-A and solar irradiation. After light exposure, all containers released VOCs, including alkanes, alkenes, alcohols, aldehydes, carboxylic acids, aromatics, etc. The 1#, 3#, 4#, 5#, and 6# containers exhibited 35, 32, 19, 24 and 37 species of VOCs, respectively. Specifically, the 2# container released 28 and 32 series of VOCs after 1-day (short-term) and 7-day (long-term) UV-A irradiation, respectively, compared to 30 and 32 species under solar irradiation. Over half of the VOCs identified were oxidized compounds alongside various short-chain hydrocarbons. Significant differences in VOC compositions among the containers were observed, potentially originating from light-induced aging and degradation of the polyethylene terephthalate structure in the containers. Toxicological predictions unveiled distinctive toxic characteristics of VOCs from each container. For example, among the various VOCs produced by the 2# container, straight-chain alkanes like n-hexadecane (544-76-3) were identified as the most toxic compounds. After long-term irradiation, the yield of these toxic VOCs from the 2# container ranged from 0.11 ng/g to 0.79 ng/g. Considering the small mass of a single bottle, the volatilization of VOCs from an individual container would be insignificant. Even after prolonged exposure to light, the potential health risks associated with inhaling VOCs when opening and drinking bottled water appear manageable.

Perinatal photoperiod associations with bipolar disorder and depression: A systematic literature review and cross-sectional analysis of the UK Biobank database

Season-of-birth associations with psychiatric disorders point to environmental (co-)aetiological factors such as natural photoperiod that, if clarified, may allow interventions toward prevention. We systematically reviewed the literature concerning season-of-birth and bipolar disorder and depression and explored associations between the perinatal natural photoperiod and these outcomes in a cross-sectional analysis of the UK Biobank database. We used mean daily photoperiod and relative photoperiod range (relative to the mean) in the 3rd trimester and, separately, in the first 3 months post birth as metrics. From review, increased risk of depression with late spring birth is compatible with increased odds of probable single episode-, probable recurrent-, and diagnosed depression (OR 2.85 95 %CI 1.6-5.08, OR 2.20 95 %CI 1.57-3.1, and OR 1.48 95 %CI 1.11-1.97, respectively) with increasing 3rd trimester relative photoperiod range for participants who experienced relatively non-extreme daily photoperiods. Risk of bipolar disorder with winter-spring birth contrasted with no consistent patterns of perinatal photoperiod metric associations with bipolar disorder in the UK Biobank. As natural photoperiod varies by both time-of-year and latitude, perinatal natural photoperiods (and a hypothesized mechanism of action via the circadian timing system and/or serotonergic circuitry associated with the dorsal raphe nucleus) may reconcile inconsistencies in season-of-birth associations. Further studies are warranted.

Imine-Decorated Copper-Based Metal-Organic Framework for the Photodegradation of Methylene Blue

A low cost imine-decorated linker, 4,4'-(hydrazine-1,2-diylidenedimethylylidene)dibenzoic acid was utilized for the preparation of copper-based metal-organic framework (MOF) denoted as Cu-L via a solvothermal technique. The synthesized MOF material has been fully characterized by different analytical techniques such as Fourier-transform infrared (FT-IR) spectroscopy, powder X-Ray diffraction (PXRD), scanning electron microscopy (SEM), energy dispersive X-Ray spectroscopy (EDX), nitrogen adsorption-desorption isotherm analysis, and thermogravimetric analysis (TGA). It has been found that the coordination of Cu2+ with L considerably reduced the band gap of the L of nearly about 1 eV, which is approximately 26% decline in total. Notably, a narrow band gap of the photocatalyst is an essential requirement for the proficient photodegradation of organic contaminants. An excellent optical properties and narrow band gap of (2.8 eV) of Cu-L ensure their suitability as a photocatalyst for the degradation of methylene blue (MB) dye. In the presence of Cu-L photocatalyst, 84.22% degradation of MB dye was observed after 150 min under sunlight exposure. It is the first time that imine-functionalized MOF was utilized for the degradation of MB dye under sunlight irradiation. For understanding the photodegradation of MB dye by the Cu-L photocatalyst, all the plausible mechanistic studies have been carried out in detail. Both theoretical (with the help of density functional theory (DFT) calculations) as well as experimental studies have been conducted to justify the possible mechanisms for the photodegradation of MB dye by Cu-L. The current work may open a new opportunity to construct a cheap MOF-based photocatalysts for fast degradation of dye contaminants.

Effect of TiO2/Fe2O3 nanopowder synthesis method on visible light photocatalytic degradation of reactive blue dye

Water pollution and scarcity of clean water are major issues of concern globally. In this study, titanium dioxide (TiO2) photocatalyst doped with ferric oxide (Fe2O3) was used to degrade reactive blue dye (171) using sunlight irradiation. Two approaches were employed to synthesize the photocatalyst: synthesis of ferric oxide and titanium precursor through ultrasonic-assisted sol-gel method and using iron (III) nitrate nonahydrate with commercial titanium dioxide. The photocatalysts were characterized using FTIR Spectroscopy, SEM, XRD analyses, and UVDRS to determine their chemical composition, morphology, crystallinity, and light absorption, respectively. The effect of contaminant concentration (1-3 ppm), solution pH and photocatalyst type on the degradation efficiency was studied. Doping enabled visible light absorption as confirmed by the UVDRS analysis. Solar photocatalytic degradation resulted in complete (100 % removal) of the dye within 2 h under solar irradiation for all concentrations of the dye studied. Furthermore, the photocatalysts exhibited superior performance in both neutral and acidic solutions compared to basic ones. After four cycles, the dye removal efficiency has decreased by less than 15 % for all the photocatalysts confirming the significant activity and high stability of the nanocomposite. The increased dye photodegradation efficacy of Fe2O3 doped TiO2 under sunlight irradiation is attributed to the narrowing of the photocatalyst's bandgap from 3.76 eV (in pure TiO2) to 2.83 eV. This narrowing of the bandgap enhances the absorption of visible light from sunlight, thus making this photocatalyst effective under sunlight and eliminating the use of electricity which is a requirement for ultraviolet photocatalysis.

Time dependence of aldehyde and ketone oxocarboxylic acid photoproduct generation from crude oil-seawater systems under solar irradiation

Aldehyde and ketone oxocarboxylic acid photoproducts were semi-quantitated in the aqueous phase after subjecting Macondo (MC252) crude oil-seawater systems to simulated solar irradiation. Electrospray ionization tandem mass spectrometry (ESI-MS/MS) was applied after derivatizing the samples with 2,4-dinitrophenylhydrazine (DNPH). Oil-seawater was irradiated at 27.0 °C using a solar simulator for 1 to 18 h. Following irradiation, the aqueous phase was treated with DNPH to generate aldehyde-DNPH and ketone-DNPH derivatives. Solid-phase extraction enriched the samples before analyzing them using (-) ESI-MS/MS. Precursor and product ion spectra were used to select carboxylic acid-containing aldehydes and ketones and provide semi-quantitation using surrogate standards and an internal standard. Loss of m/z 44 (CO2) in the product ion spectra further confirmed the carboxylic acid character. Near-linear increases in photoproduct concentration in the aqueous phase were observed over the 18 h irradiation period. Among the aldehyde and ketone oxocarboxylic acid photoproducts studied, photoproduction rates ranged from 0.6 - 69 µmol/h·m2 of oil surface. Despite some fluctuations, a general trend of lower production rate with higher molecular weight was observed. These results demonstrate the near-linear dependence of photoproduction on irradiance and provide ranges of rates that can be applied to modeling aldehyde and ketone oxocarboxylic acid photoproduction in ocean spills. STATEMENT OF ENVIRONMENTAL IMPACT: Crude oil on seawater degrades when exposed to sunlight. Oxygenated molecules are produced, including carboxylic acid-containing aldehydes and ketones. The formation of these photoproducts from oil films behaves linearly with solar exposure time. These photoproducts are more soluble than the original oil molecules, allowing them to have increased bioavailability and potentially increased toxicity. The rate of formation of these species when oil is exposed to sunlight determines their environmental impact.

Early exposure to sunlight and allergic morbidity: The PARIS birth cohort

The relationship between sunlight and allergies in children has received limited attention from researchers. We sought to explore how early exposure to solar radiation is associated with allergic morbidity within the PARIS birth cohort study. Our research dealt with children who attended at least one of two health checkups: at 18 months (n = 2012) and at 8-9 years (n = 1080). Early exposure to solar radiation was assessed using meteorological data (e.g., solar radiation, temperature, and relative humidity). Children with similar meteorological exposure trajectories were grouped by a longitudinal and multidimensional cluster analysis. The association between solar radiation exposure and allergic morbidity (i.e., allergic sensitization at 18 months and 8-9 years; current asthma, rhinitis, and eczema at 8-9 years) was quantified by multivariable logistic regression models adjusted for potential confounders. The effect modification of maternal vitamin D supplementation during pregnancy was tested. Four meteorological exposure trajectories were found. The trajectory with the highest exposure to early solar radiation had a reduced risk of sensitization at 8-9 years compared to the trajectory with the lowest exposure (p = 0.06). The association was statistically significant in the vitamin D supplementation group. Solar radiation during prenatal and postnatal periods was significantly associated with a lower risk of sensitization at 8-9 years (for one interquartile range (IQR) increase, adjusted odds ratio (aOR): 0.47; 95 % confidence interval (CI): 0.25-0.87 and 0.84; 0.7-1.00, respectively). Increased prenatal exposure to solar radiation was significantly associated with a lower risk of asthma at 8-9 years (for one IQR increase, aOR: 0.32; 95 % CI: 0.1-0.96). Early sunlight exposure may reduce the risk of sensitization and asthma in school-aged children, especially in those prenatally exposed to vitamin D. These findings highlight the importance of vitamin D in preventing allergic diseases in children, either through supplementation or sunlight exposure.

CdIn2Se4@chitosan heterojunction nanocomposite with ultrahigh photocatalytic activity under sunlight driven photodegradation of organic pollutants

This research focused on synthesizing a CdIn2Se4@Ch nanocomposite by doping CdIn2Se4 into chitosan using a photolysis assisted ultrasonic process. The aim was to enhance the photodegradation efficiency of ofloxacin and 2,4-dichlorophenoxyacetic acid under sunlight. The synthesized CdIn2Se4@Ch nanocomposite was investigated via different techniques, including XRD, XPS, FTIR, TEM, DSC, TGA, UV-Vis and PL. The study also investigated the influence of various reaction parameters, including the effects of inorganic and organic ions. The synthesized nanocomposite demonstrated exceptional efficiency, achieving 86 % and 95 % removal rates, with corresponding rate constants of 0.025 and 0.047 min-1. This performance surpasses that of CdIn2Se4 by approximately 1.35 and 2.25 times, respectively. The values of COD were decreased to 78 and 86 % for ofloxacin and 2,4-dichlorophenoxyacetic, while the TOC values decreased to 71 and 84 %, respectively, from their premier values. The improvement in performance is associated with the introduction of CdIn2Se4 into chitosan, resulting in the self-integration of Cd into the catalyst. This creates a localized accumulation point for electrons, enhancing the efficiency of charge separation and further reducing the surface charge of chitosan. Experimental evidence suggests that superoxide and hydroxyl radicals play a significant role in the photodegradation of pollutants. Additionally, the nanocomposite exhibits excellent stability and can be reused up to five times, indicating remarkable stability and reusability of the developed photocatalyst.

Prevalence of vitamin D deficiency in exclusively breastfed infants at Charoenkrung Pracharak Hospital

BACKGROUND

Vitamin D deficiency is a common problem in exclusively breastfed infants, with supplementation recommended by various international medical organizations. However, in Thailand, no advice for routine vitamin D supplementation is available. Thus, this study investigated the prevalence of vitamin D deficiency and its associated factors in exclusively breastfed infants in Bangkok, Thailand.

AIM

To investigated the prevalence of vitamin D deficiency and its associated factors in exclusively breastfed infants in Bangkok, Thailand.

METHODS

This descriptive observational cross-sectional study assessed 109 4-month-old infants at Charoenkrung Pracharak Hospital from May 2020 to April 2021. The 25-OH vitamin D level of the infants was measured using an electrochemiluminescence binding assay. Vitamin D deficiency was defined as 25-OH level < 20 ng/mL, with vitamin D insufficiency 20-30 ng/mL. The sun index and maternal vitamin D supplementation data were collected and analyzed using the independent t-test, univariate logistic regression, and multivariate logistic regression to identify the associated factors.

RESULTS

The prevalences of vitamin D deficiency and vitamin D insufficiency were 35.78% and 33.03%, respectively with mean serum 25-OH vitamin D levels in these two groups 14.37 ± 3.36 and 24.44 ± 3.29 ng/mL. Multivariate logistic regression showed that the main factors associated with vitamin D status were maternal vitamin D supplementation and birth weight, with crude odds ratios 0.26 (0.08-0.82) and 0.08 (0.01-0.45), respectively. The sun index showed no correlation with the 25-OH vitamin D level in exclusively breastfed infants (r = -0.002, P = 0.984).

CONCLUSION

Two-thirds of healthy exclusively breastfed infants had hypovitaminosis D. Vitamin D supplementation prevented this condition and was recommended for both lactating women and their babies.

Fixed Sunlight Eruption: A Series of 13 Cases in Bogotá, Columbia

Few reports describing an association between UV radiation and fixed skin eruptions have been published since 1975. These reactions have received various names, including fixed sunlight eruption, fixed exanthema due to UV radiation, and broad-spectrum abnormal localized photosensitivity syndrome. We present a series of 13 patients (4 men [30.8%] and 9 women [69.2%]) aged between 28 and 56 years who were evaluated for fixed eruptions induced by UV radiation at a dermatology referral hospital in Bogotá, Colombia. The lesions were located on the inner thighs, buttocks, popliteal region, anterior and posterior axilla, and dorsum of the feet. Photoprovocation reproduced lesions in all the affected areas, and histopathology showed changes similar to those seen in fixed drug eruptions. While these UV-provoked reactions may be a type of fixed skin eruption, we cannot rule out that they may also be a distinct condition that simply shares a pathogenic mechanism with fixed eruptions.

[Translated article] Fixed Sunlight Eruption: A Series of 13 Cases in Bogotá, Colombia

Few reports describing an association between UV radiation and fixed skin eruptions have been published since 1975. These reactions have received various names, including fixed sunlight eruption, fixed exanthema due to UV radiation, and broad-spectrum abnormal localized photosensitivity syndrome. We present a series of 13 patients (4 men [30.8%] and 9 women [69.2%]) aged between 28 and 56 years who were evaluated for fixed eruptions induced by UV radiation at a dermatology referral hospital in Bogotá, Colombia. The lesions were located on the inner thighs, buttocks, popliteal region, anterior and posterior axilla, and dorsum of the feet. Photoprovocation reproduced lesions in all the affected areas, and histopathology showed changes similar to those seen in fixed drug eruptions. While these UV-provoked reactions may be a type of fixed skin eruption, we cannot rule out that they may also be a distinct condition that simply shares a pathogenic mechanism with fixed eruptions.

Illuminated fulvic acid stimulates denitrification and As(III) immobilization in flooded paddy soils via an enhanced biophotoelectrochemical pathway

Fulvic acid (FA) is a representative photosensitive dissolved organic matter (DOM) compound that occurs naturally in paddy soils. In this study, the effect of a FA + nitrate treatment (0, 4 and 8 mg/L FA + 20 mmol/L nitrate) on denitrification and As(III) immobilization in flooded paddy soils was assessed under dark and intermittently illuminated conditions (12 h light+12 h dark). The FA input stimulated denitrification in illuminated soils (~100 % of nitrate removal within 6 days) compared to dark conditions (~92 % nitrate removal after 6 days). Meanwhile, As(III) (initial concentration of 0.1 mmol/L) was nearly completely immobilized (~100 %) under illuminated conditions after 4 days for the FA + nitrate treatment compared to 90- 93 % retention in the dark. Denitrification and As immobilization were positively related to the FA dosage in the illuminated assays. The stronger denitrification in illuminated soils was ascribed to denitrifiers harvesting photoelectrons from photosensitive substrates/semiconducting minerals. FA addition also increased the activities of denitrifying enzymes (e.g., NAR, NIR and NOR) and the denitrification electron transport system by nearly 0.6-0.7 and 1.5-1.8 times that of the nitrate-alone treatment under illuminated and dark conditions, thereby fostering stronger denitrification. Upon irradiation, As(III) immobilization was not only stimulated by the interactions with the denitrification pathway whereby As(III) acts as an electron donor for denitrifiers, but was also modulated by Fe(III)/oxidative reactive species-derived photooxidation of As(III). Moreover, the FA + nitrate treatment promoted the enrichment of metal-oxidizing bacteria (e.g., Stenotrophomonas and Acidovorax) that are responsible for nitrate-dependent As(III)/Fe(II) oxidation. The results of this study enhance our understanding of interactions among the biogeochemical cycles of As, Fe, N and C, which are intricately linked by a biophotoelectrochemical pathway in flooded paddy soils.

Impact of mixed microalgal and bacterial species on organic micropollutants removal in photobioreactors under natural light

Single microalgae species are effective at the removal of various organic micropollutants (OMPs), however increased species diversity might enhance this removal. Sixteen OMPs were added to 2 continuous photobioreactors, one inoculated with Chlorella sorokiniana and the other with a microalgal-bacterial community, for 112 d under natural light. Three media were sequentially used in 3 Periods: I) synthetic sewage (d 0-28), II) 10x diluted anaerobically digested black water (AnBW) (d 28-94) and III) 5x diluted AnBW (d 94-112). Twelve OMPs were removed > 30 %, while 4 were < 10 % removed. Removal efficiencies were similar for 9 OMPs, yet the mixed community showed a 2-3 times higher removal capacity (µg OMP/g dry weight) than C. sorokiniana during Period II pseudo steady state. The removal decreased drastically in Period III due to overgrowth of filamentous green algae. This study shows for the first time how microbial community composition and abundance are key for OMPs removal.

Bandgap engineering approach for synthesising photoactive novel Ag/HAp/SnS2 for removing toxic anti-fungal pharmaceutical from aqueous environment

The present work shed light on synthesising a novel ternary Z-scheme Ag/HAp/SnS2 (AHS) nano photocatalyst to degrade metronidazole (MTZ) in wastewater through H2O2-assisted AOP under natural sunlight. HAp extracted from the fish scales of rohu fish through alkaline treatment was decorated with Ag nanoparticles using ascorbic acid as a bio-reductant. Tin disulphide (SnS2) was anchored over Ag/HAp to prevent agglomeration and enhance photocatalytic activity by delaying the electron-hole recombination rate. After 45 min of irradiation, a degradation efficiency of 98.85 ± 1.86% for 15 ppm MTZ could be achieved. The performance of the prepared photocatalyst in real wastewater was investigated by introducing several metal cations and anions in the photodegradation process. The degradation products were identified by HRLCMS analysis, and the breakdown mechanism of MTZ was proposed. The present study enlightens the importance of SnS2-based photocatalysts for organic pollutant degradation under natural sunlight through an advanced oxidation process. The characterization results showed that the enhanced photodegradation efficiency of AHS is attributed to the formation of an all-solid-state Z-scheme heterojunction with Ag nanoparticles acting as charge transfer medium and as electron accumulators helping in delaying charge recombination.

Seasonality and clinical characteristics of MS in an equatorial country

BACKGROUND

Month and season of birth have been associated with risk of multiple sclerosis (MS), but there is relatively little evidence regarding their influence on the timing and severity of disease at onset.

OBJECTIVE

To assess whether month and season of birth influence the age and phenotype at onset of MS as well as its severity in a cohort of Colombian patients.

METHODS

This study is an analysis on MS cases only, drawn from a previously published case-control study. MS cases confirmed with current diagnostic criteria cared for at least once in our center were included. We assessed the influence of the month and season of birth in the age at MS onset, MS severity score, and age-related MS severity score using multiple and pairwise comparisons. Age at onset was also studied using Kaplan-Meier survival estimates compared with the log-rank test. The likelihood of progressive MS onset was evaluated with OR estimated from logistic regression models adjusted for age at onset and sex.

RESULTS

668 MS cases were included. No significant differences were found in the age at MS onset according to month of birth or season of birth. Neither month of birth nor season of birth conferred significant differences in MS severity score or age-related MS severity score. No significant association was found between month (ORs ranging from 0.62 to 3.11, none significant) or season of birth (OR 0.91; 95 %CI: 0.46-1.84) with primary progressive MS.

CONCLUSION

The month or season of birth do not appear to influence the age onset and phenotype of MS in our country.

[Use of sunglasses in everyday life, at work, and during outdoor sports: current results from nationwide surveys]

BACKGROUND

Ultraviolet (UV) radiation can increase the risk of eye damage. Therefore, wearing sunglasses is recommended to protect the eyes from UV rays.

OBJECTIVE

To report the latest data on the use of sunglasses in everyday life in adults, children, at work, and during outdoor sports.

MATERIAL AND METHODS

We used data from waves 2020 and 2021 from the representative National Cancer Aid Monitoring (NCAM). The use of sunglasses in everyday life was assessed in 4000 participants aged 16-65 years. Data on use during outdoor work were obtained from 486 outdoor workers and the use of sunglasses during outdoor sports from 2081 participants. Additionally, 554 adults living in a household with at least 1 child aged 1-10 years reported the use of sunglasses by children. Descriptive results and associations with demographic characteristics are reported.

RESULTS

Overall, 50.6% of the general population, 31.0% of outdoor workers, 44.3% of those who reported being engaged in outdoor sports and 12.5% of children wore sunglasses always or often while being outside for more than 10 min in summer. The infrequent use of sunglasses was associated with a younger age, male sex, and lower school education.

CONCLUSION

Because of the relatively low use of sunglasses further education in various settings (e.g., at the workplace, kindergartens, and schools) seems necessary. The general public should also be made aware of the risks of UV radiation for the eyes, especially against the background of climate change.

Sunlight, vitamin D, vitamin D receptor polymorphisms, and risk of multiple myeloma: A systematic review

This systematic review examines the relationship with multiple myeloma (MM) risk for sunlight and vitamin D related exposures, including vitamin D supplementation, circulating 25-hydroxyvitamin D concentration, personal ultraviolet B radiation exposure, ambient solar irradiance and vitamin D receptor (VDR) gene polymorphisms We conducted a search for terms related to multiple myeloma, vitamin D, vitamin D receptor, ultraviolet radiation, sunlight, and single nucleotide polymorphism (SNP) using Ovid MEDLINE, Ovid EMBASE, Web of Science and Cochrane CENTRAL. Studies were assessed for risk of bias and quality using the RoB 2.0, ROBINS-E or Q-Genie tools. We identified 13 eligible studies: one randomised controlled trial, two cohort studies, and ten case-control studies, including one nested case-control study and one meta-analysis of genome-wide association studies. We conducted a qualitative synthesis; quantitative synthesis was not appropriate due to study heterogeneity and the small number of studies identified. There was insufficient evidence to support an effect of any sunlight or vitamin D related exposure on MM risk. No polymorphisms in VDR were found to be strongly related to risk for people of European ancestry. Of the identified studies, many had high risk of bias or were of lower quality. Few studies have investigated the association between sunlight and vitamin D related exposures and multiple myeloma risk. The scarcity of high-quality studies makes it difficult to evaluate potential effects of these exposures on MM risk. Further research is necessary to investigate the influence of vitamin D related exposures on risk of multiple myeloma..

Photodegradation of MC-LR using a novel Au-decorated Ni metal-organic framework (Au/Ni-MOF)

Microcystins (MCs) are toxins produced by cyanobacteria commonly found in harmful algal blooms (HAB) occurring in many surface waters. Conventional methods for removing MC-LR such as membrane filtration and activated carbon are only phase change removal methods and are often expensive in operation and maintenance. It is urgent to develop a rapid, easy-to-use, and cost-effective method for the degradation of MC-LR. In this study, a novel Au-decorated Ni-metal-organic framework (Au/Ni-MOF) was newly developed on a hydrophilic carbon fiber paper (2 cm × 2 cm) using an air spraying method. The Au/Ni-MOF was then applied for the photodegradation of MC-LR in water under UV-Vis. The addition of Au onto the surface of the Ni-MOF resulted in a nearly fivefold enhancement in the reaction rate coefficient (k), reaching a value of 0.0599 min-1 for the photodegradation of MC-LR (initial concentration of 20 ppb). It was found that 94.2% of MC-LR removal was attributed to photodegradation, with the remaining 5.8% from adsorption. The rate coefficient of 20 ppb of MC-LR in the surface water sample (pH 6.0) was 0.06 min-1 likely due to the presence of other contaminates including scavenger agents within the sample which inhibits the degradation reaction of the MC-LR. Overall, this study demonstrated the potential for the novel Au/Ni-MOF to effectively reduce the concentration of the MC-LR toxin in the contaminated water.

Novel SnO2@Cu3(BTC)2 Composites as a Highly Efficient Photocatalyst and Fluorescent Sensor

A novel SnO2@Cu3(BTC)2 composite was synthesized using a quick and affordable bottom-up approach via impregnation of SnO2 nanoparticles into the porous Cu3(BTC)2 metal-organic framework (MOF). This composite material is characterized by Fourier transform infrared (FTIR) spectroscopy, powder X-ray diffraction (PXRD) spectra, scanning electron microscope (SEM) analysis, and energy-dispersive X-ray spectroscopy (EDS) analysis. SnO2@Cu3(BTC)2 degraded the methylene blue (MB) dye within 80 min under sunlight with a maximum degradation efficiency of 85.12%. This composite easily recyclable up to five cycles with the retention of its MB degradation efficiency. Moreover, SnO2@Cu3(BTC)2 can be also used efficiently for fast sensing of 2,4,6-trinitrophenol (TNP) in water with noticeable turn-off quenching response. Its limits of detection (LOD) for TNP was 2.82 µM with enhanced selectivity toward TNP (over other NACs) as verified by competitive nitro explosive tests. Density functional theory (DFT) calculations and spectral overlap were used to assess the sensing mechanism. This composite fluorescent sensing system for TNP are demonstrated to have high selectivity and sensitivity. Our findings imply that the prepared low cost SnO2@Cu3(BTC)2 composite can be used as a superior fluorescence sensor and photo catalyst for large scale industrial applications.

Assessing the effects of sunlight and water on asphalt binder and pavement leachability related to the environment

Extensive global research conducted over 30 years explores asphalt leachability and stormwater runoff. Asphalt's widespread usage in construction materials underscores the importance of understanding its environmental consequences. This study aims to assess the influence of sunlight exposure on water quality, particularly regarding the release of hazardous organic compounds such as polycyclic aromatic compounds. We investigated the effect of concurrent versus sequential exposure to water and sunlight, and dark versus light trials utilizing thin films of asphalt binder as well as old and freshly prepared pavement cores for analysis. Initial laboratory experiments reveal significant water-soluble species when thin asphalt films are exposed to solar simulation while underwater. However, simulating environmental conditions found in roadways by exposing the asphalt binder to solar simulation followed by water immersion leads to a substantial decrease in compound formation. Leachate water from 17-year-old asphalt and 15-year-old concrete pavements exhibits complex compound compositions associated with atmospheric and/or vehicular deposition, posing challenges in deconvoluting their origins. Light and dark trials conducted on freshly prepared asphalt pavement under environmental conditions of sunlight and rain demonstrate minimal runoff variation, with semi-volatile organic compound levels resembling the background. Future investigations will focus on applying insights gained from this study to analyze larger sample sets, with an emphasis on inherent hazardous compound variations.

Unleashing the power of solar light: WO3 nanorods decorated onto BiVO4 dendrites for tetracycline detoxification and water splitting

The coupling of different oxide materials in a nanohybrid enables the customization of their optical and charge transport properties, leading to improved interfacial charge segregation and migration. In this study, BiVO4/WO3 (BVW), a sunlight-driven photocatalyst with distinct mole ratios was synthesized via a facile hydrothermal approach. The resultant catalyst exhibits a nanorods shape morphology decorated onto dendrite-like matrix and is studied for photocatalytic elimination of tetracycline (TC) and photoelectrocatalytic (PEC) H2 production. The effect of illumination time, solution pH, photocatalyst concentration, and mole ratios of BiVO4 to WO3 on the photocatalytic abatement of TC were tested sequentially as effective operating factors. Under optimal condition, 3:1 BiVO4:WO3 (31BVW) nanohybrid demonstrated a maximum degradation efficacy of 96.2% (rate constant ~0.0241 min-1), which is much better than its individual components and commercial TiO2-P25 (50.9%). The resultant by-products of TC decomposition were analyzed using GC-MS to explain the degradation mechanism. Moreover, as a photoanode, 31BVW showed a high photocurrent density of 0.64 mA/cm2 at 1.23 V vs RHE and a steady photocurrent for ~6 h under chronoamperometry study at1.23 V vs RHE. However, bare BiVO4 and WO3 exhibited the photocurrent density of 0.001 mA/cm2, and 0.015 mA/cm2, respectively at 1.23 V vs RHE. The Mott-Schottky analysis of 31BVW confirms their n-type behavior, with a calculated flat band potential of -0.067 V. The hydrogen production rate was theoretically calculated as 4.56 mmolcm-2 s-1 from chronoamperometric measurements. The photocatalyst's efficacy in TC degradation was further established via its reusability upto 7 cycles. Post degradation characterization of catalyst confirms its stability in lieu of practical usage. Comparative studies with existing literature revealed the superiority of reported photocatalysts in both applications. Overall, the binary BVW photocatalyst shows great potential for removing detrimental contaminants as well as H2 production via PEC water splitting due to efficient charge separation, reduced recombination, high surface area, and widen absorption window of the nanohybrid.

Photo-transformation of wastewater effluent organic matter reduces the formation potential and toxicity of chlorinated disinfection byproducts

Sunlight exposure can degrade and transform discharged wastewater effluent organic matter (EfOM) in aquatic systems, potentially enhancing the feasibility of reusing wastewater for drinking purposes. However, there remains a lack of comprehensive understanding regarding the sunlight-induced changes in the molecular-level composition, characteristics, and chlorine reactivity of EfOM. Herein, we investigated the impact of sunlight on the optical properties, chemical composition, and formation of disinfection byproducts of EfOM using multiple spectroscopic analyses, high-resolution mass spectrometry, chlorination experiments, and in vitro bioassays. Upon natural sunlight exposure, we observed significant decreases in ultraviolet-visible absorbance and fluorescence intensity of EfOM, indicating the destruction of chromophores and fluorophores. Photolysis generally yields products with lower molecular weight and aromaticity, and with higher saturation and oxidation levels. Moreover, a shift within the EfOM from condensed aromatic-like compounds to tannin-like components was observed. Furthermore, sunlight exposure reduced the reactivity of EfOM toward the formation of trihalomethanes and haloacetonitriles during chlorination, while there was a slight increase in the specific formation potential of haloketones. Importantly, the disinfection byproducts resulting from chlorination of the irradiated EfOM exhibited reduced microtoxicity. Overall, this study provides new insights into alterations in EfOM under sunlight exposure and aids in predicting the health risks of effluent discharge in water environments.

Asymmetric distribution of mineral nutrients aggravates uneven fruit pigmentation driven by sunlight exposure in litchi

MAIN CONCLUSION

Sunlight boosts anthocyanin synthesis/accumulation in sunny pericarp of litchi fruit, directly leading to uneven pigmentation. Distribution discrepancy of mineral element aggravates uneven coloration by modulating synthesis/accumulation of anthocyanin and sugar. Uneven coloration, characterized by red pericarp on sunny side and green pericarp on shady side, impacts fruit quality of 'Feizixiao' (cv.) litchi. The mechanisms of this phenomenon were explored by investigating the distribution of chlorophyll, flavonoids, sugars, and mineral elements in both types of pericarp. Transcriptome analysis in pericarp was conducted as well. Sunny pericarp contained higher anthocyanins in an order of magnitude and higher fructose, glucose, co-pigments (flavanols, flavonols, ferulic acid), and mineral elements like Ca, Mg and Mn, along with lower N, P, K, S, Cu, Zn and B (P < 0.01), compared to shady pericarp. Sunlight regulated the expression of genes involved in synthesis/accumulation of flavonoids and sugars and genes functioning in nutrient uptake and transport, leading to asymmetric distribution of these substances. Anthocyanins conferred red color on sunny pericarp, sugars, Ca and Mg promoted synthesis/accumulation of anthocyanins, and co-pigments enhanced color display of anthocyanins. The insufficiencies of anthocyanins, sugars and co-pigments, and inhibition effect of excess K, S, N and P on synthesis/accumulation of anthocyanins and sugars, jointly contributed to green color of shady pericarp. These findings highlight the role of asymmetric distribution of substances, mineral elements in particular, on uneven pigmentation in litchi, and provide insights into coloration improvement via precise fertilization.

Synthesis of strontium oxide-zinc oxide nanocomposites by Co-precipitation method and its application for degradation of malachite green dye under direct sunlight

Photocatalysts workable under direct sunlight are the safe and cost-effective option for water purification. The nanocomposites of strontium oxide and zinc oxide (SZ NCs) were synthesized using coprecipitation method. The respective precursors of SZ NCs were subjected to alkaline hydrolysis and subsequently thermally treated to yield SZ NCs. The SZ NCs with different ZnO composition was synthesized by varying the concentration of ZnO precursor from 0.2 to 1 M. The structural properties of SZ NCs evaluated using X-Ray diffraction (XRD), Thermogravimetric analysis (TGA), and Differential thermal analysis DTA). The optical properties of SZ NCs studied using ultraviolet-visible (UV-Vis) spectroscopic study. The trend observed in the intensity of XRD peaks indicated the occurrence of Zn doping in the crystalline lattice of SrO and the formation of SrO-ZnO composite. Upon incorporation of 1 M of ZnO precursor, the grain size of the SrO was decreased from 49.3 to 27.6 nm. The weight loss in the thermal analysis indicates the removal of carbonates from the sample upon heating and shows the formation of an oxide structure. UV-Vis spectra confirmed that the presence of SrO enhanced the sunlight absorption of SZ NCs. The increase in the composition of ZnO precursors increased the bandgap of SrO (2.09 eV) to the level of ZnO (3.14 eV). SZ NCs exhibited heterostructure morphology, where the nanosized domains with varying shapes (layered and rod-like) were observed. Under direct sunlight conditions, SZ NCs prepared using 1 M/0.6 M of SrO/ZnO precursors exhibited 15-20 % higher photocatalytic efficiency than neat SrO and ZnO. In precise, 1 mg of this SZ NC was degraded 98 % of malachite green dye dissolved in water (10 ppm) under direct sunlight. Additionally, the thermal stability results showed that 18 % decomposition was obtained due to the degradation impurities in SrO/ZnO catalysts and the XRD results revealed that no structural change is obtained in SrO/ZnO photocatalysts after stability test. The SZ NCs can be effectively used as safe and economic sunlight photocatalysts for water purification in remote areas without the electricity.

Solar photoelectro-Fenton: A very effective and cost-efficient electrochemical advanced oxidation process for the removal of organic pollutants from synthetic and real wastewaters

Recalcitrant and toxic organic pollutants from wastewaters are scarcely removed in conventional wastewater treatment plants. To preserve the water quality, organics need to be removed by developing powerful oxidation technologies. Our laboratory proposed in 2007 a potent electrochemical advanced oxidation process (EAOP) for wastewater remediation, so-called solar photoelectro-Fenton (SPEF). This review summarizes the advances of this emerging technology up to 2022, making evident its effectiveness and cost-efficiency for the destruction of usual organic pollutants. The simultaneous action of generated hydroxyl radicals and the photolysis by sunlight explains the high oxidation power of SPEF respect to other EAOPs. The review is initiated by describing the fundamentals of the process to remark the role of the produced oxidants and the benefits of using solar irradiation in its performance. The photoelectrochemical systems used (bench tank reactor and solar pre-pilot flow plant) and the assessment of the operating variables are discussed. The characteristics of the most common homogeneous SPEF for the degradation and mineralization of several synthetic solutions of industrial chemicals, herbicides, pharmaceuticals, and synthetic organic dyes, as well as of some real wastewaters, are further described. The influence of the photoelectrochemical cell, electrodes, solution pH, electrolyte composition, Fe²⁺ and pollutant concentration, and current density is analyzed. The performance of a homogeneous SPEF-like process with active chlorine and heterogeneous SPEF processes with solid catalysts such as Fe₃O₄ and sodium vermiculite is also discussed. Finally, the advances of homogeneous SPEF combined with other techniques like solar photocatalysis, solar photoelectrocatalysis, anaerobic digestion, and nanofiltration are reported.

Remarkable photocatalytic performances towards pollutant degradation under sunlight and enhanced electrochemical properties of TiO2/polymer nanohybrids

In this work, TiO₂-based nanocomposites containing polyaniline (PANI), poly(1-naphthylamine) (PNA), and polyindole (PIN) were synthesized by effective and simple routes and posteriorly employed as photocatalysts and supercapacitors. Characterization techniques such as XRD, FTIR, FESEM, UV, and PL were employed to investigate the structural, morphological, and optical properties of materials. XRD analysis confirmed the successful formation of TiO₂ and TiO₂/polymer nanocomposites. PANI, PNA, and PIN polymers were well distributed on the surface of TiO₂ nanoparticles and were investigated/explored from the FESEM analysis. The visible light absorption and the recombination rate of photogenerated charge carriers were confirmed by the UV-Vis and PL analysis. The photocatalytic properties of the nanocomposites were investigated towards malachite green (MG) dye degradation under sunlight. The dye degradation efficiency followed the order TiO₂/PNA > TiO₂/PANI > TiO₂ > TiO₂/PIN. The higher efficiency of TiO₂/PNA can be associated with its smaller bandgap energy compared to the other materials. Electrochemical properties of materials were also examined by cyclic voltammetry and galvanostatic charge-discharge measurements using a three-electrode experiment setup in an aqueous electrolyte. TiO₂/PNA nanocomposite showed higher supercapacitor behavior compared to the other materials due to higher electrical conductivity of PNA and redox potential of TiO₂ (pseudocapacitance).

Quantum and experimental investigation of the application of Crassostrea gasar (mangrove oyster) shell-based CaO nanoparticles as adsorbent and photocatalyst for the removal of procaine penicillin from aqueous solution

The present study was designed to synthesize and characterize calcium oxide nanoparticles (using mangrove oyster shell as a precursor) and apply the synthesized nanoparticles as a photocatalyst to degrade procaine penicillin in an aqueous solution. The photocatalyst exhibited an average band gap of 4.42 eV, showed a maximum wavelength of absorbance in the UV region (i.e., 280 nm), and is a microporous nanoparticle with a particle diameter of 50 nm. The photocatalyzed degradation of the drug was conducted under natural sunlight, and the influence of parameters such as the period of contact, catalyst load, pH, initial drug concentration, and ionic strength was investigated concerning the degradation profile. The results obtained from response surface analysis indicated that an optimum degradation efficiency of about 93% can be obtained at a concentration, pH, and catalyst dosage of 0.125 M, 2, and 0.20 g respectively, at 0.902 desirabilities. The Langmuir-Hinshelwood, modified Freundlich, parabolic diffusion, pseudo-first-/second-order, and zero-, first-, and second-order kinetic parameters were tested to ascertain the best model that best described the experimental data. Consequently, the Langmuir-Hinshelwood, modified Freundlich, and pseudo-second-order models were accepted based on the minimum error and higher R² values. Based on the Langmuir-Hinshelwood rate constants for adsorption and photodegradation as well as the evaluated valence bond potential, the degradation of the drug first proceeded through the mechanism of adsorption and followed by the oxidation of the drug by superoxide (generated from the interaction of electrons that generated by through the absorption of UV radiation). The quantum chemical calculation gave evidence that pointed towards the establishment of strong agreement with experimental data and also showed that the carboxyl functional group in the drug is the target site for adsorption and subsequent degradation.

Fe/Zr-MOFs constructed by a sunlight-responsive ligand for efficient photocatalytic nitrogen fixation under ambient condition

Photocatalytic nitrogen fixation opens new opportunities for sustainable and healthier futures, and developing effective and inexpensive photocatalysts is the key. We use the ligand 3,3',5,5'-azomellitic acid (H₄abtc) to connect with Fe clusters and Zr clusters to form stable metal-organic frameworks (MOFs) Fe-abtc and Zr-abtc, both of which are responsive to visible lights for nitrogen fixation. It is worth noting that the presence of NN in the ligand makes it respond to visible lights. The tetracarboxyl group is connected to the metal cluster to form a stable structure. The field-only surface integral method verified that the ligands were successfully applied into the synthesized MOF particles, which expanded the photoresponse range and enhanced the photonic interactions of the synthesized photocatalysts compared with pure MOF particles. The best photocatalytic nitrogen fixation performance of Fe-abtc and Zr-abtc is 49.8 μmol·g_(cat.)^-1·h^-1 and 35.7 μmol·g_(cat.)^-1·h^-1, respectively, the apparent quantum efficiency (AQY) of the sample Fe-abtc is 0.56 %, and the reliability of the source of N element is proved by the isotope ¹⁵N₂. This work provides a new idea for the design of cheap and effective MOFs for photocatalytic nitrogen fixation.

Responses in honeybee and bumblebee activity to changes in weather conditions

Insect pollination, and in particular pollination by bees, is a highly valued ecosystem service that ensures plant reproduction and the production of high-quality crops. Bee activity is known to be influenced by the weather, and as the global climate continues to change, the flying frequency and foraging behaviour of bees may also change. To maximise the benefits of pollination in a changing world, we must first understand how current weather conditions influence the activity of different bee species. This is of particular interest in a country such as Ireland where inclement weather conditions are nominally sub-optimal for foraging. We observed honeybee (Apis mellifera) and buff-tailed bumblebee (Bombus terrestris) activity across a variety of weather conditions at seven apple orchards to determine how four weather variables (temperature, relative humidity, solar radiation, wind) influenced the flight activity of each species. Each orchard contained three honeybee and three bumblebee colonies, and so we were able to observe a colony of each species concurrently in the same weather conditions. Overall, honeybees were more sensitive to changes in weather than bumblebees and could be more predisposed to future changes in within-day weather conditions. Our results indicate bumblebees could compensate for low honeybee activity in inclement conditions, which supports the theory that pollinator diversity provides resilience. This may be particularly important in management of pollinators in crops that flower in the spring when weather is more variable, and to allow varied responses to global climate change.

Plant-based green fabrication of CuO-CdO-bentonite S-scheme heterojunction with enhanced photocatalytic performance for the degradation of levofloxacin

In this research, for the first time, CuO and CdO nanoparticles (NPs) were synthesized using Ferula persica and anchored on layered bentonite as a novel S-scheme nano-heterojunction (denoted as CuO-CdO-BT). Ferula persica acted as a naturally-sourced reducing agent and stabilizer for the synthesis of NPs. The performance of CuO-CdO-BT was evaluated for the degradation of levofloxacin from an aqueous solution under sunlight. The characterization results clarified that the bentonite as a support not only reduced the agglomeration of CuO and CdO NPs but also decreased the size of biosynthesized NPs, which increased the active surface of NPs and the photodegardation efficiency. The effect of operational reaction system variables was examined to optimize the photocatalytic capability of CuO-CdO-BT. Under optimum conditions (catalyst dosage = 0.4 g/L, LVF concentration = 10 mg/L and pH = 8), 96.11% of levofloxacin was degraded using CuO-CdO-BT after 30 min with degradation kinetic of 0.108 min-1, which was about 2.4 and 4.2 times higher than those of bare CuO and CdO NPs, respectively. The improvement of the photocatalytic degradation efficiency of CuO-CdO-BT compared to CuO and CdO NPs was due to preventing the recombination of charge carriers in the S-scheme system. The radical quenching experiments ascertained the generation of [Formula: see text]·OH, and [Formula: see text] species in the CuO-CdO-BT system, indicating that ·OH radicals have a more prominent role than [Formula: see text] and [Formula: see text] in the photocatalytic reaction. The six possible levofloxacin pathways of LVF degradation were suggested based on HPLC-MS analysis. Over 88.5% LVF was removed using CuO-CdO-BT after three catalyst reuse cycles, indicating a cost-effectiveness potential of the biosynthesized photocatalyst reusability. Almost complete mineralization of LVF was obtained by the CuO-CdO-BT photocatalyst after 180 min of reaction. Based on findings, the S-scheme mechanism of photo-generated electron-hole pairs transfer in the CuO-CdO-BT system was found. The unique structural features of the new generation of S-scheme heterojunction and green synthesis of NPs using plants provide promising photocatalysts to improve wastewater treatment.

Reduction of CO2 emission through a photocatalytic process using powder and coated zeolite-supported TiO2 under concentrated sunlight irradiation

The efficiency of a novel synthetic zeolite (Ze) prepared from stone cutting sludge and a natural zeolite (clinoptilolite, Cp) as the support of TiO₂ photocatalyst was examined for the CO₂ removal under solar irradiation using a designed parabolic trough collector (PTC). The used samples were characterized using XRF, BET, SEM/EDS, and XPS analyses. The enhanced sunlight irradiation obtained by PTC increased the performance of CO₂ photocatalytic removal. The maximum CO₂ adsorption by TiO₂-Ze and TiO₂-Cp composites was 21.1% and 28.4% which increased to 61.8% and 78.9% under sunlight irradiation, respectively. The efficiency of zeolite-TiO₂ composites for CO₂ removal was approximately two times higher than zeolites and TiO₂ alone. The performance of TiO₂-Ze-coated composite with lower use of photocatalyst for CO₂ adsorption and photocatalytic removal was better than that of powder one. Regeneration of TiO₂-Ze using NaOH solution improved its removal efficiency. The adsorption behavior of CO₂ on TiO₂-Ze composite was well described by the Langmuir isotherm and the pseudo-first-order kinetic model. This work promises CO₂ reduction using natural and synthetic zeolite as an efficient photocatalyst support under solar irradiation.

SnO2 and CuO anchored on zeolite as an efficient heterojunction photocatalyst for sunlight-assisted degradation of cefixime

The fabrication of heterojunction nanocomposites has been proven as a highly efficient strategy to achieve promising photocatalysts. In this study, tin oxide (SnO₂) and copper oxide (CuO) nanoparticles (NPs) were synthesized in situ using Rosmarinus officinalis and simultaneously anchored on zeolite for the fabrication of zeolite/SnO₂/CuO as a novel heterojunction photocatalyst. The performance of zeolite/SnO₂/CuO was assessed against photodegradation of cefixime as a model pharmaceutical contaminant. A good catalytic potential and synergistic effect was obtained for zeolite/SnO₂/CuO compared to pure SnO₂ and CuO NPs. Under optimum conditions, 89.65% of cefixime was degraded after 2.5 h under natural sunlight. Based on radical quenching experiments, the importance of involved oxidizing species in the photodegradation of cefixime using zeolite/SnO₂/CuO was in order of h⁺ > ^•OH > [Formula: see text]. Among studied anions, the highest inhibitory effect was observed for nitrate ion. Also, the main intermediates of the photodegradation process of cefixime in zeolite/SnO₂/CuO system were determined by HPLC-MS and the possible pathways were suggested. More than 83% cefixime was removed after three catalyst reuse cycles, indicating a cost-effectiveness potential in the reusability of zeolite/SnO₂/CuO. Also, the toxicity and plant growth tests revealed the feasibility of discharging the treated cefixime solutions to irrigate agricultural crops. Overall, the obtained results provide a promising technique with a synergistic feature for the efficient removal of organic pollutants.

Influence of sunlight on the association between 25-hydroxyvitamin D levels and sleep quality in Brazilian adults: A population-based study

OBJECTIVES

This study aimed to evaluate the association of vitamin D with sleep quality during the COVID-19 pandemic and the influence of daily sunlight on this association.

METHODS

This cross-sectional, population-based study among adults stratified by multistage probability cluster sampling was conducted from October to December 2020 in the Iron Quadrangle region of Brazil. The outcome was sleep quality, evaluated by the Pittsburgh Sleep Quality Index. Vitamin D (25-hydroxyvitamin D) concentrations were determined by indirect electrochemiluminescence and a deficiency was classified as 25(OH)D < 20 ng/mL. To assess sunlight, the average daily sunlight exposure was calculated and was classified as insufficient when less than 30 min/d. Multivariate logistic analysis was used to estimate the association between vitamin D and sleep quality. A directed acyclic graph was used to select minimal and sufficient sets of adjustment variables for confounding from the backdoor criterion.

RESULTS

In a total of 1709 individuals evaluated, the prevalence of vitamin D deficiency was 19.8% (95% CI, 15.5-24.9%), and the prevalence of poor sleep quality was 52.5% (95% CI, 48.6-56.4%). In multivariate analysis, vitamin D was not associated with poor sleep quality in individuals with sufficient sunlight. Moreover, in individuals with insufficient sunlight, vitamin D deficiency was associated with poor sleep quality (odds ratio [OR], 2.02; 95% CI, 1.10-3.71). Furthermore, each 1-ng/mL increase in vitamin D levels reduced the chance of poor sleep quality by 4.2% (OR, 0.96; 95% CI, 0.92-0.99).

CONCLUSIONS

Vitamin D deficiency was associated with poor sleep quality in individuals with insufficient exposure to sunlight.

Mitigation of ultrafiltration membrane fouling by a simulated sunlight-peroxymonosulfate system with the assistance of irradiated NOM

Oxidation pretreatments prior to ultrafiltration are hindered by the need for energy input and sludge disposal. Herein, a simulated sunlight-induced natural organic matter (NOM) for peroxymonosulfate (PMS) activation was used as pretreatment to alleviate ultrafiltration membrane fouling caused by NOM itself in the Songhua River water. When light intensity was over 100 mW/cm², the pretreatment removed NOM effectively, characterized with UV₂₅₄, dissolved organic carbon (DOC) and maximum fluorescent intensity (F_max), and improved filtration flux. At 200 mW/cm² light intensity and 0.5 mM PMS, 57.5% of UV₂₅₄ and 18.5% of DOC were removed, and humic-like fluorescent component was degraded by 84%-94% while ∼60% for protein-like substance. Membrane flux was increased by 94%, and reversible and irreversible fouling resistances were reduced by 62.4% and 51.9%, respectively. Both total fouling index (TFI) and hydraulic irreversible fouling index (HIFI) were moderately correlated with the DOC, whereas they prominently correlated with the UV₂₅₄ and the F_maxs of all fluorescence components, which could be served as key indicators to predict and control membrane fouling. Mathematical modeling showed that the pretreatment alleviated the fouling in the membrane pores and cake layer. The simulated sunlight-induced NOM (³NOM* and e_aq^¯) could activate PMS to form active species, which enabled to oxidize high molecular weight (MW) substances and mineralize low MW compounds in NOM as well as hinder their linking with inorganic cations, thereby reducing organic and inorganic membrane fouling simultaneously. This study may provide a new strategy for decentralized potable water treatment, especially in a single household or community.

Sunlight-driven antibacterial activity of a novel zinc oxide quantum dot and its optimization using Box-Behnken design-A medicament for communicable disease protective wearables

The current study focuses on microwave-assisted zinc oxide quantum dots synthesis (ZnO-QDs) from zinc oxide bionanocomposite (ZnO-BC) preparation. The novelty lies in the preparation of ZnO-QDs, since the natural elements present in ZnO-BC itself acted as a surface penetration enhancer without using any chemical agent. Under ultraviolet (UV) light ZnO-QDs emitted a blue glow, confirming the fluorescence property. Using Box-Behnken design, the experimental factors of ZnO-QDs were optimized, yielding a positive response of 350 nm absorbance and these results also matched with the UV-visible spectroscopy characterization studies of ZnO-QDs. Using Escherichia coli, the antibacterial activity of ZnO-BC in comparison to ZnO-QDs was determined using the well diffusion method and an inhibition zone ranging from 11 to 23 mm and in the broth assay the OD values were reduced by almost seven and 10 times for ZnO-BC and ZnO-QDs, respectively, when compared to the control (untreated). The antibacterial activity demonstrated that our newly prepared BC and its QDs have superior activity when compared to the standard antibiotics such as ampicillin. This type of nanomaterial can be used as a new bioactive natural material with light-assisted activity for antibacterial coatings in the manufacture of personal protective equipment.

Toxicity enhancement of nano titanium dioxide to Brachionus calyciflorus (Rotifera) under simulated sunlight and the underlying mechanisms

Nano titanium dioxide (nTiO₂) generally shows low toxicity to organisms under light-emitting diode (LED) light. However, nTiO₂ can induce production of reactive oxygen species (ROS) under ultraviolet (UV) light due to its photocatalytic activity. Therefore, it is reasonable to expect the enhancement of nTiO₂ toxicity under sunlight. To test this hypothesis, we compared the toxicity of nTiO₂ to Brachionus calyciflorus under simulated sunlight and LED light. The results showed that the 24 h-LC₅₀ of nTiO₂ to B. calyciflorus under LED light and simulated sunlight were 24.32 (95% CI: 14.54-46.81 mg/L) and 10.44 mg/L (95% CI: 6.74-17.09 mg/L), respectively. Compared with the blank control, treatments with nTiO₂ significantly affected life-table demographic parameters, population growth parameters and swimming linear speed under both simulated sunlight and LED light. However, life expectancy, net reproductive rate, average lifespan, maximal population density, and swimming linear speed in the treatments of nTiO₂ at 0.1, 1, and/or 10 mg/L showed markedly lower values under simulated sunlight than those under LED light, suggesting that simulated sunlight could enhance the toxicity of nTiO₂. In addition, markedly higher catalase (CAT) activity and malondialdehyde (MDA) content but lower glutathione (GSH) content were observed in treatment with 10 mg/L nTiO₂ under simulated sunlight than that under LED light. The results showed that compared with LED light, simulated sunlight significantly induced more oxidative stress in the presence of nTiO₂, and the ROS production was mainly localized to the corona and digestive tract of rotifers by confocal laser scanning microscope. Exposure to 10-50 μM of vitamin C, that is an effective ROS scavenger, could rescue the swimming linear speed of rotifers to the normal level in the blank control. These results suggested that oxidative damages on cell membrane might be the vital mechanism underlying the toxicity enhancement of nTiO₂ to rotifers under simulated sunlight. Thus, the previous publications under LED light may underestimate the real toxicity and environmental risk of nTiO₂ in natural conditions.

Risk perception of sun exposure and knowledge of vitamin D among the healthcare providers in a high-risk country: a cross-sectional study

BACKGROUND

High levels of vitamin D deficiency are commonly reported even in regions with abundant sunshine. This necessitates a comprehensive understanding of the determinants that influence sun exposure practices. As the primary source of health-related knowledge for the general public, the attitude of the healthcare professionals towards sunlight and their awareness related to vitamin D deficiency can be critical in this regard.

METHODS

A cross-sectional survey was conducted among 2,242 physicians, intern doctors, and senior medical students in Bangladesh from October 2019 to February 2020. A pre-tested structured questionnaire (containing twelve close-ended questions) was used. The perceptions of health risks due to sun exposure, and basic knowledge of the physiological and epidemiological aspects of vitamin D deficiency were tested.

RESULTS

An overall negative attitude towards sunlight in the context of Bangladesh was highlighted - 68% participants thought regular sun exposure would be harmful or very harmful; 26% thought the level of UV radiation was very high; 44% recommended using sunscreen always; skin burns, heat stroke, and cancer were selected as potential consequences of regular sun exposure by 45%, 21%, and 30% respondents respectively. Overall knowledge regarding vitamin D deficiency appeared to be biased towards bone health; other symptoms and associated illnesses not having obvious link to Calcium-metabolism were identified much lesser frequently. Furthermore, 'sunrise to 10 am' was identified as the best time to get vitamin D by 69% participants; 60% believed < 30 min of weekly sun exposure would be sufficient for the Bangladeshi population; an only 33% identified that prevalence of vitamin D insufficiency in Bangladesh would be 50% or more. Taking vitamin D-rich food was suggested by more respondents over regular sun exposure (43% vs. 33%) as more effective remedial strategy to curb vitamin D deficiency in Bangladesh.

CONCLUSION

In addition to highlighting some crucial knowledge gaps, results from this study provides a comprehensive baseline dataset for knowledge and attitude regarding the public health aspects of vitamin D deficiency among the healthcare providers in Bangladesh, which would be generalizable to other countries with similar socio-demographic context, and will facilitate taking more effective policies worldwide.

Knowledge, Practice, and Factors Affecting Sunlight Exposure of Infants Among Mothers at Governmental Health Facilities in Dessie Town, Ethiopia, 2021

Background

Human being needs sunlight for physical and mental well-being. Sunlight helps the body to produce vitamin D, an important vitamin for skeletal development, immune function, and blood cell formation. So, the community should be counseled to get sufficient sun exposure and vitamin D supplementation to uphold the serum 25 (OH) D levels. This study designed to assess the mothers' knowledge, practice, and factors affecting the sunlight exposure of their infants.

Methods

A facility-based cross-sectional study was conducted at governmental health facilities in Dessie Town, 2021. A total of 398 mothers were interviewed using semi structured questionnaires. Data were entered into the EPI data version 3.1 and analyzed using SPSS 23. Binary and multivariate logistic regression analyses were also performed. In multivariate analysis, a significant association was considered at P-value of <.05.

Results

Response rate was 98.9%. About 76.6% and 58.9% of the mothers had poor knowledge and poor practice regarding sunlight exposure of infants respectively. Mothers' occupation (aOR = 0.124, 95% CI = 0.042, 0.365), mothers' source of information (aOR = 18.604, 95% CI = 7.564, 45.75), and attitude (aOR = 2.773, 95% CI = 1.474, 5.215) had showed a significant association with mothers' knowledge. On the other hand, mothers' age (aOR = 3.191, 95% CI = 1.334, 7.633), mothers occupation (aOR = 4.226, 95% CI = 2.321, 7.694), and baby age (aOR = 1.989, 95% CI = 1.260, 3.140) had a significant association with their practice about sunlight exposure of infants.

Conclusion

Mothers' knowledge and practice of sunlight exposure of infants are poor in Dessie Town. Hence measures should be taken to increase and improve mothers' responsiveness of sunlight exposure of infants.

Socio-Ecological determinants of myopia in rural school students in North India: Results from a nurse-led program

Socio-ecological determinants of high myopia incidence among school students largely remain unexplored, especially in developing countries. A cross-sectional study was conducted in rural schools in North India to assess the relationship between these determinants and myopia among adolescent students. A public health nurse used a pre-tested questionnaire (demographics, family ocular status, and screen time) and Snellen's chart for testing visual acuity, and referred suspected cases for cycloplegic refraction assessment. Among the total of 955 students, the median (range) age was 14 (13-15) years. The prevalence of myopia was 5.03% (95% confidence interval [CI]: 4.99-5.07). Myopia was found to be associated with computer usage at school (P = 0.058), malnutrition (P = 0.001), and familial myopia (P = 0.079) in the bivariate analysis. Significant predictors of myopia in the regression model were females (odd ratio [OR]: 6.29; 95% CI: 2.69-14.72), higher maternal age (OR: 1.09; 95% CI: 1-1.17), and reading distance <20 cm (OR: 1.98; 95% CI: 1.01-3.87).

Natural lighting enhancing the algae proliferation and nitrogen removal in membrane-aerated bacterial-algal biofilm reactor

Membrane-aerated bacterial-algal biofilm reactor (MABAR) is an emerging and novel technology in recent years, which has been attracting increasing attention due to its cost-effectiveness and superior removal performance of pollutants by versatile removal pathways in symbiotic bacterial-algal biofilm. However, the wider application of MABAR is hindered by the dilemma of insufficient algae biomass. In this study, an MABAR under natural sunlight was developed and operated for 160 d to access the feasibility of enhancing algae proliferation by natural lighting. Results showed that the MABAR with natural sunlight (nMABAR) demonstrated better performance of pollutants removal. High removal efficiencies of organic matter and NH₄-N in nMABAR were 90 % and 92 %, respectively. In particular, the removal efficiency of TN in nMABAR, under less aeration, was up to 80 %, which was 15 % higher than the control reactor. The Chlorophyll-a content indicated that natural sunlight facilitated to algae growth in MABAR, and algae assimilation might be the dominant contributor to NH₄-N removal. Moreover, there were microbial shifts in bacterial-algal biofilm in a response to the natural lighting, the nMABAR uniquely possessed a bacterial phylotype termed Thiocapsa, which could play an important role in bacterial nitrification. Algal phylotype Chlorophyceae significantly contributed to pollutants removal and synergistic relationship with bacteria. In addition, the superb performance of nMABAR under less aeration condition suggested that abundant algae were capable of supplying enough O₂ for the system. These results provided insight into the natural lighting on algae-bacteria synergistic growth and cost-effective operation strategy for MABAR.

Synthesis of MoS2/Mg(OH)2/BiVO4 hybrid photocatalyst by ultrasonic homogenization assisted hydrothermal methods and its application as sunlight active photocatalyst for water decontamination

In this work, MoS₂/Mg(OH)₂/BiVO₄ ternary hybrid photocatalyst was synthesized by sonicated precursor mixture to the hydrothermal procedure to generate a highly efficient solar light-induced and simply recyclable photocatalyst. The obtained hybrid was confirmed by the characteristic peaks of MoS₂/Mg(OH)₂/BiVO₄ observed in X-ray diffraction (14.31°/18.62°/28.18°), infrared spectra (465/445/679 cm^-1), ultraviolet-visible spectra (636/683/639 nm) studies, and the band-gap narrowing (2.62/2.44/2.25 eV). The morphological structure of MoS₂ (rod), Mg(OH)₂ (particles), and BiVO₄ (random aggregates) were turned into MoS₂/Mg(OH)₂/BiVO₄ hierarchical nanosheets that coexisted with particles. The photodegradation experiments of the photocatalysts were assessed by using Congo Red (CR), Malachite Green (MG) and Textile Industry Effluent (TIE) as the model pollutant under direct sunlight. The photocatalytic efficiency of the hybrids was noticeably 2.1 to 2.3 times higher than that of the individual components. Photocurrent response test indicate that MoS₂/Mg(OH)₂/BiVO₄ ternary hybrid nanocomposites photocatalysts had a more effective electron/hole pair separation than individual and binary composite photocatalysts. The mechanism of photodegradation of MoS₂/Mg(OH)₂/BiVO₄ternary hybrid photocatalysts was investigated and discussed.

Sunlight Parameters Influence the Survival and Decline of Salmonella and Escherichia coli in Water

ABSTRACT

The effect of variations in temperature, UV radiation, and sunlight intensity on Escherichia coli, E. coli O157:H7, Salmonella Newport, and antibiotic resistant (ABR) variants of E. coli O157:H7 and Salmonella Newport exposed to sunlight was evaluated. Bacterial strains suspended in sterile deionized water at a concentration of 8 log CFU/mL were exposed to sunlight on three different days for 180 min; control treatments were stored in the dark. The mean temperature of 30.08 and 26.57°C on day 1 and day 3, respectively, was significantly different (P < 0.05). The UV intensity was significantly different on all 3 days, and sunlight intensity significantly differed on day 3 (P < 0.05). Bacterial population decline positively correlated with temperature, sunlight, and UV intensity. Differences in bacterial population declines differed among species, ABR profile, and day of exposure (P < 0.05). On day 1 and day 2, the populations of E. coli dropped below the limit of detection (1 log CFU/mL), whereas the percentage of live cells was 67 and 6.6%, respectively. The artificial neural network model developed to predict bacterial survival under different environmental conditions suggested that Salmonella cells were more resistant than E. coli cells. The ABR strains had significantly higher numbers of viable cells after sunlight exposure (P < 0.05). Sunlight-exposed cells resuscitated in tryptic soy broth varied in maximum population density and maximum specific growth rate based on bacterial species and presence of ABR. Morphological changes such as viable but nonculturable state transition and filament formation were detected in subpopulations of sunlight-exposed bacteria. Daily fluctuations in UV and sunlight intensity can result in significant variations in bacterial decline and recovery.

HIGHLIGHTS

Photocatalytic dye degradation using nickel ferrite spinel and its nanocomposite

Coloured wastewater is a major issue of today for human health and ecology. Among all available processes such as physical, chemical, biological and electrochemical methods, photocatalysis can be a promising solution because of its ability to degrade colour-causing compounds completely by converting them into simpler molecules (H₂O, CO₂) depending on dye structure. In this work, NiFe₂O₄ was synthesized by the co-precipitation method. Furthermore, the composites of NiFe₂O₄ with TiO₂ were synthesized by varying amounts of TiO₂. The spinel and composites were characterized by XRD, ZETA analysis and UV-DRS. Their photocatalytic activities were investigated using the photocatalytic degradation of reactive turquoise blue 21 (RB 21) dye as model pollutants under sunlight. The increased absorption of the visible light and the enhanced separation of the electron-hole pairs due to the relative energy band positions in NiFe₂O₄ and TiO₂ are considered as the main advantages. Our results showed that NiFe₂O₄-based nanocomposites could be used as an effective and magnetic retrievable photocatalyst.

Mesocosm constructed wetlands to remove micropollutants from wastewater treatment plant effluent: Effect of matrices and pre-treatments

The contamination of the aquatic environment by micropollutants (MPs) brings risks for the ecosystem and human health. Constructed wetlands (CWs) were an eco-friendly technology to remove MPs from wastewater treatment plant effluent. In this study, the removal of MPs was evaluated in seven vertical flow mesocosm CWs with different configurations, including different support matrices (sand and a combination of bark-biochar), light pre-treatments (UVC and sunlight) or bioaugmentation in support matrices (activated sludge). The CWs with bark-biochar as support matrix significantly enhanced the removal of irbesartan and carbamazepine (>40 %), compared to the CW filled with the conventional support matrix sand. UVC irradiation as pre-treatment was more efficient in removing MPs than sunlight irradiation. After UVC pre-treatment, less MPs accumulated in the plants in the subsequent CW unit compared to the CW unit without any pre-treatment. Moreover, in the UVC combined CW system, less sulfamethoxazole, furosemide, mecoprop and diclofenac were accumulated in the plants (<0.5 μg) than other MPs (>3 μg). The addition of 0.5 % activated sludge combined with the aeration of influent did not improve MP removal in the CW. Considering the application, a bark-biochar based CW combined with UVC pre-treatment will result in more MP removal than a conventional sand CW.

Climatic exposures in childhood and the risk of schizophrenia from childhood to early adulthood

BACKGROUND

Season of birth is a risk factor of schizophrenia, and it is possible that cumulative exposure to climatic factors during childhood affects the risk of schizophrenia. We conducted a cohort study among 365,482 persons born in Finland in 1990-1995 to examine associations of 10-year cumulative exposure to global solar radiation and ambient temperature in childhood with schizophrenia.

METHODS

Data on schizophrenia diagnoses and sociodemographic factors from the Finnish population register and health care register were linked to daily meteorological data using residential information. The study population was followed from age 10 until the first schizophrenia diagnosis, death, emigration or December 31, 2017, whichever came first. Hazard ratios (HR) for the risk of schizophrenia were estimated using Cox proportional hazards model.

RESULTS

Compared to the lowest quintile of global solar radiation or ambient temperature, growing up in the second highest quintile (Q4) was associated with greater risk of schizophrenia. These hazard ratios were attenuated after adjustment for parental mental disorder, parental education, parental income, area-level socioeconomic characteristics and urbanicity (HR = 1.29, 95 % CI 1.06-1.58 for radiation; HR = 1.24, 95 % CI, 1.02-1.52 for temperature). Continuous linear terms evaluated in secondary models suggested a greater risk of schizophrenia at greater childhood exposure to global radiation and ambient temperature, but these associations did not remain in fully adjusted models.

CONCLUSIONS

We found no consistent evidence that cumulative exposure to sunlight and ambient temperature in childhood is associated with the risk of developing schizophrenia. Studies in other populations residing in different latitudes are needed.

Artificial Intelligence-Aided Low Cost and Flexible Graphene Oxide-Based Paper Sensor for Ultraviolet and Sunlight Monitoring

The adverse effect of ultraviolet (UV) radiation on human beings has sparked intense interest in the development of new sensors to effectively monitor UV and solar exposure. This paper describes a novel low-cost and flexible graphene oxide (GO)-based paper sensor capable of detecting the total amount of UV or sun energy delivered per unit area. GO is incorporated into the structure of standard printing paper, cellulose, via a low-cost fabrication technique. The effect of UV and solar radiation exposure on the GO paper-based sensor is investigated using a simple color change analysis. As a result, users can easily determine the amount of ultraviolet or solar energy received by the sensor using a simple color analysis application. A neural network (ANN) model is also explored to learn the relation between UV color intensity and exposure time, then digitally display the results. The accuracy for the developed ANN reached 96.83%. The disposable, cost-effective, simple, biodegradable, safe, and flexible characteristics of the paper-based UV sensor make it an attractive candidate for a variety of sensing applications. This work provides new vision toward developing highly efficient and fully disposable GO-based photosensors.

Association between polarity of first episode and solar insolation in bipolar I disorder

OBJECTIVE

Circadian rhythm disruption is commonly observed in bipolar disorder (BD). Daylight is the most powerful signal to entrain the human circadian clock system. This exploratory study investigated if solar insolation at the onset location was associated with the polarity of the first episode of BD I. Solar insolation is the amount of electromagnetic energy from the Sun striking a surface area of the Earth.

METHODS

Data from 7488 patients with BD I were collected at 75 sites in 42 countries. The first episode occurred at 591 onset locations in 67 countries at a wide range of latitudes in both hemispheres. Solar insolation values were obtained for every onset location, and the ratio of the minimum mean monthly insolation to the maximum mean monthly insolation was calculated. This ratio is largest near the equator (with little change in solar insolation over the year), and smallest near the poles (where winter insolation is very small compared to summer insolation). This ratio also applies to tropical locations which may have a cloudy wet and clear dry season, rather than winter and summer.

RESULTS

The larger the change in solar insolation throughout the year (smaller the ratio between the minimum monthly and maximum monthly values), the greater the likelihood the first episode polarity was depression. Other associated variables were being female and increasing percentage of gross domestic product spent on country health expenditures. (All coefficients: P ≤ 0.001).

CONCLUSION

Increased awareness and research into circadian dysfunction throughout the course of BD is warranted.

Photooxidation of Fe(II) to schwertmannite promotes As(III) oxidation and immobilization on pyrite under acidic conditions

Pollution of arsenic (As) in acid mine drainage (AMD) is a universal environmental problem. The weathering of pyrite (FeS₂) and other sulfide minerals leads to the generation of AMD and accelerates the leaching of As from sulfide minerals. Pyrite can undergo adsorption and redox reactions with As, affecting the existing form and biotoxicity of As. However, the interaction process between As and pyrite in AMD under sunlight radiation remains unclear. Here, we found that the oxidation and immobilization of arsenite (As(III)) on pyrite can be obviously promoted by the reactive oxygen species (ROS) in sunlit AMD, particularly by OH. The reactions between hole-electron pairs and water/oxygen adsorbed on excited pyrite resulted in the production of H₂O₂, OH and O₂^-, and OH was also generated through the photo-Fenton reaction of Fe²⁺/FeOH²⁺. Weakly crystalline schwertmannite formed from the oxidation of Fe²⁺ ions by OH contributed much to the adsorption and immobilization of As. In the mixed system of pyrite (0.75 g L^-1), Fe²⁺ (56.08 mg L^-1) and As(III) (1.0 mg L^-1) at initial pH 3.0, the decrease ratio of dissolved total As concentration was 1.6% under dark conditions, while it significantly increased to 69.0% under sunlight radiation. The existence of oxygen or increase in initial pH from 2.0 to 4.0 accelerated As(III) oxidation and immobilization due to the oxidation of more Fe²⁺ and production of more ROS. The present work shows that sunlight significantly affects the transformation and migration of As in AMD, and provides new insights into the environmental behaviors of As.

Remarkable sunlight-driven photocatalytic performance of Ag-doped ZnO nanoparticles prepared by green synthesis for degradation of emerging pollutants in water

In this work, Ag-doped ZnO nanoparticles (NPs) were synthesized by a simple green method using a toxic agent-free route for photocatalytic purposes, toward methylene blue (MB) removal in water under sunlight irradiation. The effects of operating parameters, such as catalyst dosage, dye concentration, and pH, on the MB removal efficiency, were investigated. The presence of Ag on the ZnO structure resulted in superior catalytic activity compared to the pure ZnO sample. High removal efficiency for MB, corresponding to 95%, was obtained in 30 min of reaction time only, using Ag-doped ZnO NPs. This result can be related to its smaller bandgap energy (1.92 eV) when compared to the ZnO sample (2.85 eV). The material presented a satisfactory level of reusability after three consecutive cycles. In addition, a reaction mechanism for MB photodegradation onto Ag-doped ZnO NPs under sunlight irradiation was suggested. Overall, the catalyst prepared via the green route in this work exhibited excellent photocatalytic activity under sunlight for MB degradation in an aqueous solution.