Currently, there is little comparative data on the colloidal stability and the toxicity of ultraviolet (UV)- and visible-light (VL)-transformed graphene oxide (GO). In order to identify this knowledge gap, the physicochemical properties of UV/VL-transformed GO are investigated in detail. Attempts are made to correlate the physicochemical alterations of UV/VL-transformed GO to the observed changes in its colloidal properties and toxicity. The results show that both UV and VL irradiations induce the significant change in the color, UV–vis absorbance, morphology, surface charge, size, oxygen containing functional groups, total of carbon, and photoluminescence properties of GO. The photo-reaction behavior of GO under UV exposure is different from that under VL irradiation in terms of reaction rate, order, and extent. Finally, the UV and VL irradiations show different effects not only on the colloidal stability of GO in the City water and Dongpu Lake water, but also on the toxicity of GO to Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus bacteria. This study clearly shows how the environmental fate and risk of GO are modified by UV and VL irradiations.

While various bioremediation techniques have been widely used at oil spill sites, the in situ efficiency of such techniques on recovering the benthic communities in intertidal areas has not been quantified. Here, the performance of several bioremediation tools such as emulsifiers, multi-enzyme liquid (MEL), microbes, and rice-straw was evaluated by a 90-days semi-field experiment, particularly targeting recovery of benthic community. Temporal efficiency in the removal of sedimentary total petroleum hydrocarbons (TPH), reduction of residual toxicity, and recovery of bacterial diversity, microalgal growth, and benthic production was comprehensively determined. Concentrations of TPH and amphipod mortality for all treatments rapidly decreased within the first 10 days. In addition, the density of bacteria and microphytobenthos generally increased over time for all treatments, indicating recovery in the benthic community health. However, the recovery of some nitrifying bacteria, such as the class Nitrospinia (which are sensitive to oil components) remained incomplete (13–56%) during 90 days. Combination of microbe treatments showed rapid and effective for recovering the benthic community, but after 90 days, all treatments showed high recovery efficiency. Of consideration, the “no action” treatment showed a similar level of recovery to those of microbe and MEL treatments, indicating that the natural recovery process could prevail in certain situations.

The bioremediation potential of an aquifer contaminated with tetrachloroethene (PCE) was assessed by combining hydrogeochemical data of the site, microcosm studies, metabolites concentrations, compound specific-stable carbon isotope analysis and the identification of selected reductive dechlorination biomarker genes. The characterization of the site through 10 monitoring wells evidenced that leaked PCE was transformed to TCE and cis-DCE via hydrogenolysis. Carbon isotopic mass balance of chlorinated ethenes pointed to two distinct sources of contamination and discarded relevant alternate degradation pathways in the aquifer. Application of specific-genus primers targeting Dehalococcoides mccartyi species and the vinyl chloride-to-ethene reductive dehalogenase vcrA indicated the presence of autochthonous bacteria capable of the complete dechlorination of PCE. The observed cis-DCE stall was consistent with the aquifer geochemistry (positive redox potentials; presence of dissolved oxygen, nitrate, and sulphate; absence of ferrous iron), which was thermodynamically favourable to dechlorinate highly chlorinated ethenes but required lower redox potentials to evolve beyond cis-DCE to the innocuous end product ethene. Accordingly, the addition of lactate or a mixture of ethanol plus methanol as electron donor sources in parallel field-derived anoxic microcosms accelerated dechlorination of PCE and passed cis-DCE up to ethene, unlike the controls (without amendments, representative of field natural attenuation). Lactate fermentation produced acetate at near-stoichiometric amounts. The array of techniques used in this study provided complementary lines of evidence to suggest that enhanced anaerobic bioremediation using lactate as electron donor source is a feasible strategy to successfully decontaminate this site.

In this study, the synthesis of Fe₃O₄@GO@g-C₃N₄ ternary nanocomposite for enhanced photocatalytic degradation of phenol has been investigated. The surface modification of Fe₃O₄ was performed through layer-by-layer electrostatic deposition meanwhile the heterojunction structure of ternary nanocomposite was obtained through sonicated assisted hydrothermal method. The photocatalysts were characterized for their crystallinity, surface morphology, chemical functionalities, and band gap energy. The Fe₃O₄@GO@g-C₃N₄ ternary nanocomposite achieved phenol degradation of ∼97%, which was significantly higher than that of Fe₃O₄@GO (∼75%) and Fe₃O₄ (∼62%). The enhanced photoactivity was due to the efficient charge carrier separation and desired band structure. The photocatalytic performance was further enhanced with the addition of hydrogen peroxide, in which phenol degradation up to 100% was achieved in 2 h irradiation time. The findings revealed that operating parameters have significant influences on the photocatalytic activities. It was found that lower phenol concentration promoted higher activity. In this study, 0.3 g of Fe₃O₄@GO@g-C₃N₄ was found to be the optimized photocatalyst for phenol degradation. At the optimized condition, the reaction rate constant was reported as 6.96 × 10⁻³ min⁻¹. The ternary photocatalyst showed excellent recyclability in three consecutive cycles, which confirmed the stability of this ternary nanocomposite for degradation applications.

Lead (Pb) both in paints and children's Polyvinyl chloride (PVC) toys is a major public health concern which has attracted attention of the international community. Concentrations of Pb both in lead-based paints and children's PVC toys have been assessed through various studies across the globe. Therefore, the purpose of this article was to summarize the results reported in these studies and provide some comprehension on their implications to human health for law enforcement as well as for awareness raising to the general public. Highlights on identified gaps have been provided to pave ways for further research interventions in order to establish comprehensive information on the subject.Regardless of regulatory limits on the content of lead, both in paints and children's PVC toys existing in different countries in the world, some of the reviewed articles have revealed significant levels of lead in these two items far above the permissible limits.High lead levels in paints have been recorded in China (116,200 ppm), Cameroon (500,000 ppm), South Africa (189,000 ppm), Tanzania (120,862.1 ppm), Uganda (150,000 ppm), Thailand (505,716 ppm) and Brazil (170,258.4 ppm) just to mention a few.Lead poisoning cases in children have been reported in several countries including France, Morocco, South Africa and United States. Countries where high levels of lead in children's PVC toys have been recounted include; China (860,000 ppm), South Africa (145,000 ppm), United States (22,550 ppm), Thailand (4,486.11 ppm), Palestine (6,036 ppm) and India (2,104 ppm).Awareness raising among parents is vital to impart them with knowledge on the matter so that they can take strenuous measures to protect their children from lead poisoning emanating from playing with toys and paint dust. Law enforcement on phasing out lead-based paints and control of lead content in children's PVC toys worldwide is also highly recommended.

Size-segregated ambient particles down to particles smaller than 0.1 μm (PM₀.₁) were collected during the year 2014–2015 using cascade air samplers with a PM₀.₁ stage, at two cities in Thailand, Bangkok and Chiang Mai. Their characteristics and seasonal behavior were evaluated based on the thermal/optical reflectance (IMPROVE_TOR) method. Diagnostic indices for their emission sources and the black carbon (BC) concentration were assessed using an aethalometer and related to the monthly emission inventory (EI) of particle-bound BC and organic carbon (OC) in order to investigate the contribution of agricultural activities and forest fires as well as agro-industries in Thailand. Monthly provincial EIs were evaluated based on the number of agricultural crops produced corresponding to field residue burning and the use of residues as fuel in agro-industries, and also on the number of hot spots from satellite images corresponding to the areas burned by forest fires. The ratio of char-EC/soot-EC describing the relative influence of biomass combustion to diesel emission was found to be in agreement with the EI of BC from biomass burning in the size range <1 μm. This was especially true for PM₀.₁, which usually tends to be indicative of diesel exhaust particles, and was shown to be very sensitive to the EI of biomass burning. In Chiang Mai, the northern part of Thailand, the forest fires located upwind of the monitoring site were found to be the largest contributor while the carbon behavior at the site in Bangkok was better accounted for by the EI of provinces in central Thailand including Bangkok and its surrounding provinces, where the burning of crop residues and the cultivation of sugarcane for sugar production are significant factors. This suggests that the influence of transportation of polluted air masses is important on a multi-provincial scale (100–200 km) in Thailand.

Tungstate enrichment in aquatic systems may cause negative environmental and health effects. This study addresses tungstate removal from aqueous solution by nanocrystalline iowaite, an iron-bearing layered double hydroxide, which has not been used for treatment of tungstate-rich waters so far. Tungstate sorption experiments were conducted with various contact times, temperatures, initial tungstate concentrations (0.001–2 mM), and solution pH values (2–13), the results indicating that iowaite sorbed aqueous tungstate effectively and quickly, and the sorption maximum can be up to 71.9 mg/g. Moreover, the tungsten sorption capacity keeps nearly constant at a wide pH range from 3 to 11. Duo to its pH buffering effect, the alkaline conditions were generated by the addition of iowaite, which are favorable for the removal of aqueous tungstate because the polymerization of tungstate can be prohibited at alkaline pH values. Zeta potential, XRD and XPS analyses were employed to clarify the sorption mechanisms, and it was concluded that tungstate was sorbed via its exchange with the chloride originally intercalated into iowaite interlayers as well as its stronger inner-sphere complexation with the Fe atoms located in iowaite layers. Nanocrystalline iowaite is suitable for treating both tungstate-bearing natural waters with moderately high tungstate concentrations and industrial wastewaters extremely rich in tungstate.

Organic pollutants are widely detected in surface water, groundwater and irrigation sewage in farmland soil, some of which can form complexes with heavy metal ions as ligands in the environment. Acesulfame (ACE), one of the most popular artificial sweeteners, has been found in wastewater sometimes at tens of microgram per liter. However, the combined effects of heavy metals and ACE are still unclear. In the present study, the effects of ACE on cadmium (Cd) absorption and translocation in rice seedlings (Oryza sativa L.) under different exposure conditions were investigated using hydroponic experiments. Under the combined exposure treatments of ACE and Cd, absorption of Cd and ACE in rice significantly decreased when compared with the single exposure treatments, while the alleviation of oxidative damage in rice was also found. Under the sequential exposure treatments of Cd and ACE, the post-exposed ACE activated the pre-absorbed Cd in plant, and accelerated the release of Cd to the environment as well as its translocation from the roots to shoots. In addition, compared with the single Cd exposure, the accumulated ACE can alleviate the oxidative damage in rice shoots induced by Cd, although the Cd concentrations in shoots changed little. In summary, the combined pollution of artificial sweetener ACE was beneficial to relieve the toxicological damage and ecological risk caused by Cd.

As the frequency, intensity, and duration of heatwaves increases, emergency health serviceutilization, including ambulance service, has correspondingly increased across the world. The negative effects of air pollution on health complicate these adverse health effects. This research work is the first known study to analyze the joint effects of heatwaves and air quality on the ambulance service in Western Australia (WA). The main objective is to investigate the potential joint effects of heatwaves and air quality on the ambulance service for vulnerable populations in the Perth metropolitan area. A time series design was used. Daily data on ambulance callouts, temperature and air pollutants (CO, SO₂, NO₂, O₃, PM₁₀ and PM₂.₅) were collected for the Perth metropolitan area, WA from 2006 to 2015. Poisson regression modeling was used to assess the association between heatwaves, air quality, and ambulance callouts. Risk assessments on age, gender, socio-economic status (SES), and joint effects between heatwaves and air quality on ambulance callouts were conducted. The ambulance callout rate was higher during heatwave days (14.20/100,000/day) compared to non-heatwave days (13.95/100,000/day) with a rate ratio of 1.017 (95% confidence interval 1.012, 1.023). The ambulance callout rate was higher in males, people over 60 years old, people with low SES, and those living in coastal areas during period of heatwaves. Exposure to CO, SO₂, O₃ and PM₂.₅ increased risk on ambulance callouts and exposure to NO₂ showed joint effect with heatwave and increased risk of ambulance callouts by 3% after adjustment of all other risk factors. Ambulance callouts are an important indicator for evaluating heatwave-related emergency morbidity in WA. As the median concentrations of air pollutants in WA were lower than the Australian National Standards, the interactive effects of heatwaves and air quality on ambulance service need to be further examined, especially when air pollutants exceed the standards.

The increased bioeconomy targets for the biomass share of renewable energy production across Europe should be met using land unsuitable for food production. Miscanthus breeding programs targeted the production of plants with a diverse range of traits allowing a wider utilization of land resources for biofuel production without competing with arable crops. These traits include increasing tolerances to drought, chilling, and to metal(loid)s excess. Two novel Miscanthus hybrids, GNT41 and GNT34, were compared against Miscanthus x giganteus (Mxg) on metal-contaminated arable land in Poland. This study aimed at evaluating their yield, biomass quality and quantifying seasonal differences in photosynthetic and transpiration parameters. A secondary objective was to identify key physiological mechanisms underlying differences in metal accumulation between the investigated plants. The new hybrids produced a similar yield to Mxg (13–15 t ha−1 yr−1), had shorter shoots, higher Leaf Area Index and stem number. Based on gas exchange measurements, GNT34 exhibited isohydric (water-conserving) behavior. The stomatal response to light of the new hybrids was at least twice as fast as that of Mxg, a trait that is often associated with increased seasonal water use efficiency. This contributed to the almost 40% reduction in shoot Pb and Cd concentrations for the new hybrids as compared to Mxg. This suggested that promoting stomatal regulation in conjunction with improved water conservation may be a target for improving plants for wider use on metals contaminated land.