Three soil core samples were collected from a forest located about 1.1 km south of the Fukushima Daiichi Nuclear Power Plant (FDNPP) boundary in 2017, and the vertical profiles of 129I from the FDNPP accident were determined by the combination of TMAH (tetramethyl ammonium hydroxide) extraction and ICP-MS/MS analysis. The humus layer above the soil layer was heavily contaminated with 134Cs (1983–5985 Bq g−1) and 137Cs (1947–5902 Bq g−1) (decay-corrected to March 11, 2011). The 129I activity concentrations decreased sharply with the soil depth, from 1894 to 34.1, from 9384 to 78.9, and from 2536 to 51.3 mBq kg−1, for the three sites. Downward migration of 129I was slightly faster than the one of 134Cs. In addition, the cumulative 129I inventories were observed to be 43.4 ± 1.0, 71.7 ± 1.8, and 56.5 ± 1.8 Bq m−2, respectively. Subsequently, the cumulative 131I inventories were estimated to be 1.76 ± 0.06, 2.90 ± 0.11, and 2.28 ± 0.10 GBq m−2 (decay-corrected to March 11, 2011), respectively. Finally, the total atmospheric deposition of 129I on the land of Japan due to the FDNPP accident was estimated to be around 1.09–1.71 kg (7.11–11.2 GBq).

The magnetic Fe₃O₄ was synthesized by using a one-step solvothermal method. Then, anhydrous ethanol as a solvent, tetramethyl ammonium hydroxide (TMAOH) as an auxiliary agent, tetraethyl orthosilicate (TEOS) as a silicon source, and (3-aminopropyl) triethoxysilane (APTES) as amino source were used to prepare Fe₃O₄@mSiO₂-NH₂ by using the sol-gel method. Uniform design U14*(14⁵) and the response surface method (RSM) were used to optimize the synthesis ratio. According to the results of TEM, SEM, N₂ adsorption–desorption test, VSM, and XRD, it found that the best coating effect obtained when the relative molar ratio of TMAOH:TEOS:APTES:Fe₃O₄ was 5:4:6:0.45. The results of EDS and elemental analysis confirmed the success of amino group coating; VSM magnetization after surface modification was 32 emu/g; BET results show that specific surface area is 236 m²/g, size 5 nm, and the pore volume is 0.126 cm³/g. The removal of Cu²⁺, Zn²⁺, and Pb²⁺ by Fe₃O₄@mSiO₂-NH₂ was studied at the optimal initial pH value 6 of the adsorption test system. The isothermal adsorption results show that the Langmuir model and Redlich–Peterson model are more suitable than the Freundlich model to describe the adsorption behavior, and Cu²⁺, Zn²⁺, and Pb²⁺ adsorption is mainly single molecular layer. The maximum adsorption capacity qm of the Langmuir model for Cu²⁺, Zn²⁺, and Pb²⁺ removal was 48.04 mg/g, 41.31 mg/g, and 62.17 mg/g, respectively. The adsorption kinetic rates of Cu²⁺, Zn²⁺, and Pb²⁺ on Fe₃O₄@mSiO₂-NH₂ relatively more suitable for pseudo-second-order kinetic model, i.e., R², were ranged between 0.995 and 0.999, and the suitable reaction time was 60 min. These results proved that Fe₃O₄@m-SiO₂-NH₂ prepared by using this method is easy to synthesize, has easy recovery, is ecofriendly, and can be potential adsorbent for Cu²⁺, Zn²⁺, and Pb²⁺ removal.

Rhodamine B (RhB) is a cationic organic dye widely used industrially, mainly in the textile and food industries. Then, the work aims to study on the photocatalytic degradation of RhB dye, under UV and visible radiation, using photocatalyst silica-based materials synthesized by sol-gel route with different solvents (ethanol and n-propanol) and catalysts (C₁₂H₂₇N, HNO₃, NH₄OH, and NaOH) to the hydrolysis and condensation of tetraorthosilicate (TEOS). In addition, the effect of doping with silver nanoparticles (AgNPs) was evaluated on the photocatalytic activity. The samples were characterized by X-ray diffraction (XRD), diffuse reflectance spectroscopy (DRS), N₂ porosimetry, zeta potential measurements (ZP), and Fourier transform infrared spectroscopy (FTIR). To evaluate the photocatalytic activity, photocatalytic tests were carried out in a stirred batch reactor, with the photocatalyst in suspension, under ultraviolet and visible radiation, and the target molecule chosen was the Rhodamine B dye (RhB). The photocatalyst Si–HNO₃–AgNPs showed the best photocatalytic activity with a degradation of the RhB dye of 90.16% (k = 0.0198 min⁻¹, under ultraviolet radiation) and 82.79% (k = 0.0148 min⁻¹, under visible radiation), after 120 min of reaction; while under the same conditions, the commercial catalyst TiO₂ (P25) showed a degradation of 50.02% and 42.14%, respectively.

Herein, three different types of zinc ferrite (ZnFe₂O₄) magnetic nanoparticles as photocatalysts were synthesized from iron and zinc sulfate using a co-precipitation method. Tri ethylene glycol (TEG) was utilized as a capping/stabilizing agent in the presence of ammonium hydroxide. The as-prepared nanoparticles were annealed at 400 °C for 4 h followed by acid etching with HCl (for 15 min in I M solution). The thermally treated magnetic nanostructure was subjected to surface modification by treating with 3-aminopropyl (triethoxysilane) 3-(APTES) at 60 °C for 2 h. Various characterization techniques including Fourier transform infrared (FTIR), Brunauer-Emmett-Teller (BET), and X-rays diffraction (XRD) were carried out to examine the structural properties of the pristine and functionalized nanocrystals. XRD pattern assessed the crystalline and nano size of the ZnFe₂O₄ recording particle sizes of 13.5, 23.3, and 106.5 nm for functionalized, annealed, and pristine ZnFe₂O₄ nanoparticles, respectively. FTIR spectral analysis corroborated the modifications and functionalization of the samples. BET analysis revealed a surface area of 0.6719 (functionalized), 45.21 (annealed), and 155.38 (pristine nanoparticles). The photocatalytic activity of the prepared nanostructures was investigated for Eriochrome Black T (EBT) dye under the unfiltered sunlight. At optimal reaction parameters, the photocatalytic rates of EBT dye for functionalized, annealed, and blank NP’s were 92, 91, and 83%, respectively. Kinetic models demonstrate that the degradation processes followed pseudo-first-order kinetics. The energies of the band gap in the acidic and basic media, as determined from the Tauc plot, were 2.47 and 2.7 eV, respectively. Taken together, the results showed that newly fabricated nanostructures are considered as promising photocatalysts in degrading organic pollutants for a sustainable environment.

Nowadays, the increasing pollution of natural water effluents with surfactant, wetting, dispersing, and emulsifying agents which contain nonylphenol ethoxylate (NP₇EO) is an emerging problem that has not received the enough attention. Currently, it is known that degrading this type of highly stable compounds is possible through advanced electrochemical oxidation (AEO), but the degradation of NP₇EO has not been tested yet. Thus, this work carries out a study of the degradation of the NP₇EO (500 mg L⁻¹) through advanced electrochemical oxidation, using a DiaClean® cell, equipped with boron-doped diamond electrodes (BDD, 70 cm²). The cell operated in a recirculation system with a peristaltic pump, which allowed to control the electrolyte flow. The buffer media for degradation was NH₄OH 0.1 M/HCl 0.05 M (pH 9.25). The effect of the current density (j = 20, 30, 40 mA cm⁻²) was studied, and the cell efficiency for each condition was evaluated. The degradation was followed by total organic carbon (TOC), chemical oxygen demand (COD), and absorbance. The cell potential was monitored to determine the operating costs. The best conditions for the mineralization of NP₇EO (initial concentration = 500 mg L⁻¹) were applying 40 mA cm⁻² and at a flow rate of 12.6 L min⁻¹ during 8 h of electrolysis, achieving a 90% of TOC removal. Therefore, this technology appears as a promising alternative for degrading surfactants like NP₇EO in aqueous media.

Biogeochemical cycles of bromine (Br) and its quantitative requirements for different plant species are still studied poorly. There is a need to examine Br pathways in plants and evaluate the factors important for Br accumulation in a plant. In the present work, the effects of different Br compounds on an uptake of Br by two plant species (wheat and pea) that tolerate Br differently (pea is more sensitive to Br compared with wheat) have been studied. The growth medium was spiked with either KBr or NaBr at concentrations 0, 10, 50 and 100 mg/L. Elemental analysis of the plants was performed using inductively coupled plasma optical emission spectrometry (ICP-OES) and ICP-MS analytical techniques after leaching of the samples with tetramethyl ammonium hydroxide at mild temperature (60 °C). The experimental results have shown that wheat and pea seedlings can accumulate rather large amounts of Br. An increase of Br concentration in a plant was not always directly proportional to the variations in the Br concentration in the growth medium. In wheat, the greater part of Br was accumulated during first 7 days. In pea, the uptake of Br lasted until the end of the experiment. Certain differences in the ability of plants to accumulate Br were observed when the plants were grown in a medium spiked with different Br compounds. In most cases, Br accumulation was higher in the leaves of the plants grown in the medium spiked with KBr. The same tendency was observed for another halogen, chlorine (Cl).

A fast and reliable method was developed for simultaneous trace determination of nine odorous and estrogenic chloro- and bromo-phenolic compounds (CPs and BPs) in water samples using solid-phase extraction (SPE) coupled with liquid chromatography tandem mass spectrometry (LC-MS/MS). For sample preparation, the extraction efficiencies of two widely applied cartridges Oasis HLB and Sep-Pak C18 were compared, and the Oasis HLB cartridge showed much better extraction performance; pH of water sample also plays important role on extraction, and pH = 2–3 was found to be most appropriate. For separation of the target compounds, small addition of ammonium hydroxide can obviously improve the detection sensitivity, and the optimized addition concentration was determined as 0.2%. The developed efficient method was validated and showed excellent linearity (R ² > 0.995), low limit of detection (LOD, 1.9–6.2 ng/L), and good recovery efficiencies of 57–95% in surface and tap water with low relative standard deviation (RSD, 1.3–17.4%). The developed method was finally applied to one tap and one surface water samples and most of these nine targets were detected, but all of them were below their odor thresholds, and their estrogen equivalent (EEQ) were also very low.

Increases in global wildfires and fire severity are expected to result from global warming. Severe wildfires not only burn surface vegetation but also affect forest soil. Humic substances play key roles in the transport of nutrients and the carbon cycle in terrestrial ecosystems. In this study, we evaluated the effects of forest fires on the chemical properties of fulvic acid (FA) and humic acid (HA) extracted from non-burned and burned forest soils in Gunma, Japan. The differential thermal analysis of FA indicated that the intensity of exothermic reaction peak at 400 °C was 2-fold higher than that from non-burned soil. Based on pyrolysis-gas chromatography-mass spectrometry analysis with tetramethyl ammonium hydroxide, the amount of pyrolysate compounds in FA from burnt soil was significantly lower than that in FA from non-burnt soil. Therefore, we can conclude that the forest fire caused the significant change in the properties of FA such as increasing the aromaticity and refractory. In addition, the concentration of dissolved organic carbon with low molecular weight in surface soil increased after forest fire. This study suggests that the denaturation of soil organic matter by wildfire can affect the carbon cycle in terrestrial ecosystems.

Currently in South Africa, online flue gas desulphurisation (FGD) is being utilized as one of the most effective methods for total sulphur reduction in coal samples during the combustion process. However, the main disadvantage associated with FGD is the formation of its by-products (FGD gypsum). The latter is mostly formed in low grade quality, thereby bringing secondary pollution problems and extra disposal costs. Therefore, the current study describes the development of total sulphur extraction in coal under microwave heating using different dilute alkaline solutions such as NaOH, NaOH-H₂O₂, NH₄OH, and NH₄OH-H₂O₂. The experimental conditions were as follows: 150 °C, 5 min and 10% (m/v or v/v) for temperature, extraction time and reagent concentration, respectively. The most effective alkaline reagent for coal desulphurisation was observed to be NaOH-H₂O₂ with total sulphur reduction of 55% (from the inductively coupled plasma-optical emission spectrometry (ICP-OES) results). The NaOH-H₂O₂ reagent also showed significant morphological changes in coal as observed from the SEM images and effective demineralisation as revealed by the powder X-ray diffractometer (P-XRD) results. Additionally, desulphurisation results obtained from the developed microwave-assisted dilute alkaline extraction (MW-ADAE) method were quite comparable with the published work. The proposed total sulphur reduction method is advantageous as compared to some of the literature reported coal desulphurisation methods as it requires a short period (5 min) of time to reach its completion. Additionally, the proposed method shows excellent reproducibility (% RSD from 0.5 to 1); therefore, it can be utilized for routine analysis. Graphical abstract ᅟ

Gastric ulcer is a worldwide disease. Helicobacter pylori is one of the most common chronic bacterial infections that induce chronic inflammation in the gastric mucosa, mediated by an array of pro-and inflammatory cytokines. The aim of this study was to investigate the possible therapeutic effects of Ginkgo biloba extract on gastric ulcer induced by ammonium hydroxide in rats and the potential underlying mechanisms. The study was done on 32 adult male Wistar albino rats, divided equally into 4 groups: normal control, gastric ulcer–induced group using 1 ml of 1% NH₄OH orally, ulcer control group; rats received 1% carboxymethyl cellulose daily for 14 days after induction of ulcer and treated rats received orally 200 mg/kg Ginkgo biloba once daily for 14 days after induction of ulcer. The study revealed administration of ammonia showed multiple gastric lesions; edema, hyperemia, hemorrhage, and ulcers with a significant increase in ulcer score, myeloperoxidase (MPO), and interleukin-1β (IL-1β) and a significant decrease in reduced glutathione (GSH), mucus amount, and gastric pH. After the administration of Ginkgo biloba, there was an improvement in gastric lesions, with a significant reduction of ulcer score, MPO, and IL-1β and a significant increase in GSH, mucus content, and gastric pH. Moreover, collagen types I and IV were gradually increased in the treated group.