TiO 2 and N-TiO 2 -photocatalytic degradation of salicylic acid in water: characterization of transformation products by mass spectrometry Abstract The aim of this work is to study the byproducts formed as a result of the photocatalytic process under different conditions of light wavelength and photocatalyst doping, rendering valuable information about the fate of pollutants for water treatment applications. Salicylic acid was selected as a model emerging pollutant and powders of nitrogen-doped titanium dioxide (N-TiO2) and TiO2 were prepared by the sol-gel process, using TiO2 P-25 Degussa as benchmark. Two light sources, UVA fluorescent tubes (372 nm) and blue LEDs (462 nm), were employed for photolysis and photocatalysis experiments. Transformation products formed during the process were studied by high-performance liquid chromatography coupled to mass spectrometry (HPLC-MS). Major differences were found in the amount and identity of the transformation products due to the different light sources, detecting similar transformation products among the studied catalysts. Under UVA light, hydroxylated and carbonylated byproducts were the first intermediates to reach maximum abundances whereas presumed ring opening products were the last ones. On the other hand, under blue LED illumination byproducts accumulated with decreased mineralization. Photocatalytic degradation pathways were proposed based on the findings.

Ionic cross-linking of cellulose nanofibers: an approach to enhance mechanical stability for dynamic adsorption Abstract Herein, we attempt to improve the mechanical stability of anionic functionalized cellulose nanofibers (a-CNF) having 1.25 mmol of carboxymethyl groups per gram of cellulose nanofibers (CNF). The a-CNF and cross-linked a-CNF (za-CNF) then used for water desalination in the continuous mode using a tubular adsorption column. It is worth mentioning that the za-CNF possess 40% degree of cross-linking provided better mechanical stability as the tensile strength improved from 3.2 to 5.2 MPa over a-CNF. The IR spectroscopy was used to confirm the success of chemical modifications. Upon ionic cross-linking, the BET surface area reduced from 13.53 to 7.54 m2·g−1 corresponds to a-CNF and za-CNF, respectively. Moreover, this research was extended to determine the dynamic adsorption capacities for a-CNF and za-CNF, which were found to be 21 and 10 mg·g−1 respectively at a flow rate of 5-mL·min−1 explained by Thomas model.

Simultaneous removal of SO 2 and NO by Fe II (EDTA) solution: promotion of Mn powder and mechanism of reduction Abstract The effect of Mn powder addition on the simultaneous removal of SO2 and NO coupled with FeII(EDTA) absorption was investigated in this work. In the NO absorption system with FeII(EDTA), SO2 reduced FeII(EDTA)-NO to FeII(EDTA) with a reduction efficiency reaching 88.5% under the conditions of 4000 mg/m3 SO2, pH 8.0, 44 °C, and the flow rate of 1.2 L/min within 60 min. Introducing 0.1 M Mn powder with SO2 increased the FeII(EDTA)-NO reduction efficiency to 96.8% within 5 min. SO2 was also removed by reducing FeII(EDTA)-NO and converted into SO42- at a removal efficiency of 100%. After adding Mn powder, NO was removed through the following reaction: \( 5\mathrm{Mn}+2{\mathrm{Fe}}^{\mathrm{II}}\left(\mathrm{EDTA}\right)-\mathrm{NO}+12{\mathrm{H}}^{+}\longrightarrow 2{\mathrm{Fe}}^{\mathrm{II}}\left(\mathrm{EDTA}\right)+5{\mathrm{Mn}}^{2+}+2{\mathrm{NH}}_4^{+}+2{\mathrm{H}}_2\mathrm{O} \) . Mn powder functioned as a reductant to regenerate the absorption of solution, and the coordinated NO in FeII(EDTA)-NO was reduced to NH4+. The resource utilization rate of N reached approximately 77.2%. The integrated technology is a potential solution for flue gas treatment in industrial sectors with coal-fired power plants and industrial boiler. Graphical abstract

Chlordecone exposure and risk of congenital anomalies: the Timoun Mother-Child Cohort Study in Guadeloupe (French West Indies) Abstract Chlordecone is an organochlorine pesticide that was extensively used to control the banana root borer population in the French West Indies until 1993. Its persistence in soil has led to widespread pollution of the environment, and human beings, including pregnant women, are still exposed to this chemical. High levels of exposure to chlordecone during gestation have been shown to cause congenital anomalies, including undescended testes in rodents. We assessed the associations between chlordecone concentrations in maternal and cord plasma and the risk of congenital anomalies in the Timoun Mother-Child Cohort Study (2004–2007) that included 1068 pregnant women in Guadeloupe. Odds ratios were estimated using unconditional logistic regression analysis, controlling for confounding factors. The median plasma concentrations in maternal and cord plasma were 0.39 μg/L and 0.20 μg/L, respectively. Thirty-six children were diagnosed with malformations according to the European Registration of Congenital Anomalies guidelines and 25 with undescended testes. There was no association between maternal or cord plasma concentration of chlordecone and the risk of overall malformations nor undescended testes. These results suggest that prenatal exposure to the currently observed environmental levels of chlordecone in French West Indies does not increase the risk of birth defects.

Saline soil reclamation by agroforestry species under Kalaât Landelous conditions and irrigation with treated wastewater in Tunisia Abstract Irrigation with treated waste water (TWW) in combination with plantation of agroforest species was tested in the Kalaât Landelous region for the reclamation of salt affected soils. Five species (Atriplex nummularia, Eucalyptus gomphocephala, Acacia cyanophylla, Casuarina glauca, Pinus halepensis) were cultivated in saline soils that are affected by shallow, saline groundwater and were irrigated with TWW during the summer season. The results after 4 years of experimentation show a distinct decrease in soil pH and salinity accompanied by a decrease in Cl and Na concentrations. Irrigation decreased the heavy metal concentrations in the topsoil but an increase in deeper layers indicate to leaching due to TWW irrigation. The investigated plant species were differently affected in growth performance by salinity and TWW irrigation. Atriplex nummularia appeared to be the most resistant species and Pinus halepensis the most sensitive one to hydro-pedological conditions of the Kalaât Landelous plot. In conclusion, salt-tolerant plant species seem to be good candidates for the reclamation of salt-affected, waterlogged sites in combination with TWW irrigation, as the adaptations of such species seem to operate under different abiotic stress conditions.

Multiorgan histopathological changes in the juvenile seabream Sparus aurata as a biomarker for zinc oxide particles toxicity Abstract Zinc oxide nanoparticles are widely used in some domains (cosmetics, pharmaceuticals optical devices, and agricultural field) due to their physical, optical, and antimicrobial properties. However, the release of ZnO-NPs into the environment may affect organisms like fish with potential consequences for human health. Histological approaches of the acute effects of these materials on fish are scarce; thus, the present study aimed to investigate the potential toxic effects of acute exposure to ZnO particles in marine environments, by assessing histological changes in the gills, liver, spleen, and muscle of gilthead seabream (Sparus aurata) juveniles. Thus, fish were exposed for 96 h, via water, to 1 mg L−1 of ionic zinc and zinc oxide particles (1.1, 1.2, and 1.4 μm of size). Histological examination revealed gills as the most affected organ, followed by liver, muscle, and spleen. In the gills, histopathological changes included hyperplasia of epithelial cells, fusion of the secondary lamellae, and lifting of the lamellar epithelium with edema. In the liver, lipid vacuolation of several degrees, necrosis of hepatic and pancreatic tissues, blood congestion in sinusoids and hepatoportal vessels, presence of cellular infiltrate, and melano-macrophages diffusion was found. Muscle showed degeneration, atrophy, thickening and necrosis of muscle fibers with edema between them, and presence of melano-macrophages in the muscle layer. Spleen was the less damaged organ, displaying congested blood, white pulp increase/rupture, and bigger and darker melano-macrophage aggregates in the splenic stroma. These results underline that the size of particles plays a determinant role in their potential pernicious effects. A short-term exposure caused major histopathological changes in relevant organs of S. aurata juveniles, possibly affecting their function.

Mapping the research of energy subsidies: a bibliometric analysis Abstract A review of energy subsidy research from a bibliometric perspective was conducted. Based on the bibliometric method, a statistical analysis of energy subsidy–related publications from 1997 to 2016 was undertaken using the Science Citation Index (SCI) and Social Science Citation Index (SSCI) databases. A total of 1182 publications were retrieved, with a significant increase in the number of publications observed after 2006. The majority of these publications were within the disciplines of Energy & Fuels and Environmental Science & Ecology. Although the USA and China contributed the most papers, authors from 96 countries were involved in the various studies. The USA was the center of global collaborations, while other countries/territories mainly conducted bilateral or regional collaborations in their research activities. Five of the top 11 most productive institutes were from China, followed by the USA. The frequency of collaborations among institutes was relatively low. However, the institute–keyword 2-mode network showed that institutes had great potential to cooperate on a number of common topics. Five major themes were identified from the co-keywords analysis: general renewable energy research, bio-energies, sustainability, subsidies, and welfare. The findings, as a complement to previous conventional reviews, will be useful in future energy subsidy research.

Synthesis and characterization of GO/FeSO 4 composites for the effective removal of Hg 2+ and Cd 2+ ions from the synthetic effluent Abstract Heavy metals like Cd and Hg removal using novel graphene oxide/ferrous sulfate (GO/FeSO4) was taken for experimental studies and analysis. In this work, GO/ FeSO4 was synthesized by both modified Hummer’s and chemical precipitation method. The synthesized composite was characterized by field emission scanning electron microscope (FESEM), Fourier transform infrared (FTIR) spectroscopy, and Raman spectroscopy for their properties. Brunauer Emmett-Teller (BET) analysis was characterized for the surface analysis of the prepared nanocomposites. FESEM images exhibit flake-like structures in surface morphological studies. FTIR peaks confirmed the presence of carboxyl groups in GO. Raman spectroscopy intensity peak [ID/IG ratio1.18] confirmed the synthesized sample was GO. The experimental parameters such as initial concentration, pH, and adsorbent dosage were optimized to achieve maximum heavy metal removal efficiency. The influence of initial heavy metal concentration (0.2–1 mg/L), pH of solution (pH 3–7), and adsorbent dosage (1–5 g/L) was studied and reported. Adsorption kinetic studies were performed and the process was found to fit well with pseudo-second-order kinetics.

Morpho-physiological characteristics of Vigna unguiculata [L.] Walp grown in a controlled environment using effluents from a beverage bottling company Abstract The use of industrial effluents for agricultural practices due to waste management properties, water scarcity, or cultural belief affects both the physiology and morphology of cultivated crops. This study reports the investigation of the agro-potentiality of the effluents from a beverage bottling company on cowpea (Vigna unguiculata) under a controlled environment. This greenhouse experiment was carried out within Obafemi Awolowo University. The effluents were applied at 0, 10, 20, 30, 40, and 50% concentrations using untreated (A) and treated (B) effluents separately in two groups. Physicochemical properties of the effluents were determined using standard methods. Exchangeable cations present in the effluents were investigated via the ammonium acetate exchange way. Morphological and yield parameters were measured in ten replicates. Transverse sections of the leaf, petiole, and stem were also investigated under a light microscopy. General linear model was used for statistical analysis with means compared using Tukey’s HSD test at p < 0.05. The effluents had pH, electrical conductivity, and total dissolved solids in the range of 7.4–7.5, 599.0–693.0 μS/cm, and 395.0–455.0 mg/l, respectively. The exchangeable calcium and potassium concentrations in the effluents range 1067.00–1937.50 and 190.0–343.50 mg/l. Application of effluent A had no significant effect on number of pods per group, seeds per pod, leaf length, leaf width, and leaf area of cowpea (p > 0.05). There was a significant effect of effluent A on the number of leaves and shoot height (p < 0.05). The application of effluent B had a significant effect on the mean number of leaves and seeds per pod at higher (40–50%) concentrations (p < 0.05). Amendment with effluent B showed no significant effect on the mean shoot height, leaf length, width and area, pods per group, pod length, and girth size (p > 0.05). The frequency of guard cells was observed to decrease with increasing effluents (A and B) concentration on the abaxial epidermis. Likewise, a “black deposit” was observed in the vessels in the stem taken from group amended with effluent A at high concentrations (30–50%). No anatomical differences were observed in the petiole and leaf transverse sections of the control and amended subgroups. The untreated and treated effluents showed agro-potentiality. However, crops grown need to be monitored for the health impacts on man and animal, as risk of crop cellular disruption exist.

Occurrence and ecological risk of pharmaceutical and personal care products in surface water of the Dongting Lake, China-during rainstorm period Abstract The pharmaceutical and personal care product (PPCP) residues in freshwater lakes are being highlighted around the world. The occurrence and ecological risk of 34 PPCPs classified as antibiotics, non-steroidal anti-inflammatory drugs (NSAID), cardiovascular drugs, psychotropic drugs, anti-inflammatory drugs, psychostimulants, and pesticides during rainstorm period in surface water of the Dongting Lake, China, were studied. Twenty-six out of thirty-four PPCPs were detected, and the total concentrations of antibiotics ranged from 0.15 to 214.75 ng L−1 in surface water. The highest average concentration was observed for diclofenac, followed by diethyltoluamide (DEET). The PPCP concentrations were much lower in Dongting Lake compared to other rivers and lakes due to the strong dilution effect of rainstorm, while the detection rate remains high. Caffeine and DEET were detected with 100% frequency in Dongting Lake, and the detection rates of diclofenac, mefenamic acid, and roxithromycin were above 90%. The pollution levels of antibiotics decreased in the order of East Dongting Lake > South Dongting Lake > West Dongting Lake, which may be related to the distribution of aquaculture plants, sewage treatment plants, and population density. The risk quotient (RQ) method was used to evaluate ecological environment risk under the worst case and the results suggested that clarithromycin, diclofenac, roxithromycin, and erythromycin might pose a significant risk to aquatic organisms in Dongting Lake, especially clarithromycin. This study can provide data support for further research on the dilutive effect and mechanism of rainwater runoff on PPCPs in lakes on a large scale.