Environmental Science and Pollution Research最新文献

The membrane transporters of plants are important for the transport and distribution of heavy metals, which is the basis for accumulation of heavy metals in hyperaccumulators. Pot and hydroponic experiments were conducted in order to understand effects of Cd dose (0, 10, 20 mg·kg^-1) on the transport pathway of Cd in hyperaccumulator Arabis alpina, the concentrations of transporter CAX (cation/H⁺ reverse transporter) and HMA (heavy metal ATPase), and the response of Cd distribution to the inhibitors DNP (2,4-dinitrophenol), which is oxidative phosphorylation uncoupling agent and reduce HMA activity. The results showed that the concentrations of transporter CAX and HMA in roots under 20 mg∙kg^-1 Cd treatment decreased by 31% and 561% compared with under 10 mg∙kg^-1 Cd treatment, respectively. The Cd contents of the roots and leaves under 20 mg∙kg^-1 Cd treatment were significantly increased by 1.95 and 1.84 times compared with 10 Cd mg∙kg^-1 Cd treatment (P < 0.05), the similar increase trend for subcellular components. Cd contents in saps of apoplast, symplasm, phloem, and xylem under 20 mg∙kg^-1 Cd treatment significantly increased by 78%, 287%, 238%, and 191% compared with 0 mg∙kg^-1 Cd treatment, respectively. The internal flow rates of Cd²⁺ showed in sequence: endodermis > leaf vein > epidermis (root xylem). Cd with DNP treatment was mainly distributed in the cell wall, which accounted for 92%. The Cd contents of A. alpina leaves decreased by 17% and 33% with 10 mg·L^-1 Cd + 25 or 50 µmol·L^-1 DNP treatments, respectively. The results suggested that the symplast should be the main pathway of Cd transport in A. alpina root related to transporter CAX. Cd loading from endodermis to xylem based on HMA and Cd transport in phloem should be the key for Cd distribution of A. alpina.

The combustion characteristics and gas emissions behavior of Low-calorie Indonesian coal (LC), Shaanxi coal (SC), and Datong coal (TC) were analyzed by a thermogravimetric-Fourier transform infrared spectrometer (TG-FTIR). The results showed that LC was the easiest coal to burn, followed by SC and TC. The main components of LC ash were alkali metals and alkaline earth metals (AAEMS), while SC and TC were clay minerals. The catalytic activity of LC ash was higher than that of SC and TC ash. FTIR results indicated that the main functional groups of three coals were CO₂, CO, H₂O, phenols, C = O, and C-H during combustion. The absorbance peaks of CO₂, CO, SO₂, and HCN against temperature showed single peak characteristics, while NO_x was the bimodal peak. The total CO₂ emission of LC was 1.04 and 1.25 times that of SC and TC. Compared to LC and SC, TC had the highest total CO and SO₂ emissions. The total NO_x emission of LC, SC, and TC was 0.21, 0.21, and 0.16. The study results provide the guidance for selection of coals and control the emission of gas products in the thermal power plant.

TiO₂ was immobilized on a polypropylene polyhedral (PP) ball using polyamide (PA) hot melt adhesive to generate floating photocatalyst TiO₂-PA/PP with high photocatalytic activity, which was further coupled with denitrification biofilm to form TiO₂-PA/PP biofilm system. The analysis of SEM, EDS, XRD, and FTIR confirmed that TiO₂ was immobilized on the surface of PP without any changes in the crystal structure of TiO₂. The photocatalytic experiments showed that the degradation efficiencies of p-phenylenediamine, sucrose, humic acid, and bovine albumin by TiO₂-PA/PP were 58.3%, 48.0%, 97.1%, and 66.6%, respectively. •O₂^- and h⁺ were the key reactive oxygen species (ROSs) in photocatalytic degradation of organic matter in the TiO₂-PA/PP system under solar irradiation. In the synthetic water, 95.5% humic acid and 43.2% nitrate were simultaneously removed in TiO₂-PA/PP biofilm reactor, confirming the coupling of photocatalytic degradation and denitrification. In the actual micro-polluted surface water, the coupling photocatalytic and biofilm reactor reduced chemical oxygen demand (COD) by 68.4% and nitrate by 38.9% in 480 min. This study provided a new option for the in-situ removal of organic matter and nitrate from micro-polluted surface water.

Cabbage is a widely consumed vegetable in the human diet because of its low cost, broad availability and high nutritional value. The rising use of pesticides in food production creates a need to assess vegetable toxicity, which primarily results from residues in food products and environmental exposure. The study aims to offer exploration of vegetable toxicity in cabbage with the help of reliable QSTR and q-RASTR models. All the developed models were robust and predictive enough (Q²_LOO = 0.7491-0.8164, Q²F₁ = 0.5243-0.6253, Q²F₂ = 0.513-0.617, MAE_ext = 0.495-0.690). Furthermore, the reliability and predictability of models were assessed and confirmed by applicability domain and prediction reliability indicator analysis. Additionally, different machine learning models were developed to making effective predictions and multiple linear regression (MLR) comparison. Consensus approach was advocated data gap filling for USEPA ECOTOX database compounds. The most and least toxic compounds from both MLR model predictions were prioritized and analyzed. Mechanistic interpretation highlighted the structural features or fragments responsible for the agrochemical toxicity and a safe approach for designing green chemicals minimizing the toxicity. This first reported study can be useful for toxicity profiling, data gap filling and designing safer and green agrochemical for minimizing vegetable toxicity, healthy human life and environmental safety.

The potential adsorbent for inhibitors of corrosion in HCl 1.0 M was investigated using experimental and modeling data on a novel cationic polymeric resin composite called Amberlite™ IRC-200. The resin has a significantly better ability to adsorb the Ni(II) ions. Molecular dynamics (MD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and DFT theory were among the methods used to examine the polymeric adsorbent resin. In this work, the adsorbent cationic polymeric resin is used to suppress corrosion in HCl 1.0 M. Experimental results demonstrated that ACQ and DAQ significantly increased MS corrosion resistance; results from Tafel polarization demonstrated that resin polymeric compounds exhibited disordered-type inhibitory properties with varying corrosion rates. Results from the highest best impedance experiments showed that at 100 ppm, ACQ inhibited performance to a 94.9% degree. Adsorption of the cationic adsorbent polymeric resin followed the most recent findings in the Langmuir model, and the most recent estimations of thermodynamic parameters indicated physisorption. Scanning transmission electron microscopy was used to investigate the MS morphological investigation.

Soil contamination by heavy metals represents a critical environmental risk. Innovative and sustainable remediation strategies are urgently needed to address this global challenge. Biochar, derived from biomass pyrolysis, has gained attention as an eco-friendly material for heavy metal adsorption. However, its adsorption performance is highly dependent on the pyrolysis conditions and can be further enhanced through functionalization. In this study, wheat straw biochar was optimized for enhanced porosity, carbon content, and structural stability and further functionalized by incorporating metal-organic frameworks (MOFs) to create a high-performance nanocomposite. Three MOFs-ZIF-8, UiO-66, and MIL-100(Fe)-were evaluated for their Cu^2⁺ and Pb^2⁺ adsorption capacities. MIL-100(Fe) emerged as the most effective due to its high pore volume and iron-active sites. Coating biochar with MIL-100(Fe) increased its surface area sixfold, achieving 419 m²∙g^-1, and doubled its sorption capacity for heavy metals in soil (142 mmol·kg^-1 for Cu^2⁺ and 156 mmol·kg^-1 for Pb^2⁺). Advanced characterization techniques, including XAFS, XRD, and SEM-EDX, revealed that the sorption mechanisms were dominated by complexation and cation exchange, with the nanocomposite demonstrating superior metal immobilization compared to neat biochar. These findings highlight the potential of the nanocomposite as an effective amendment for reducing heavy metal toxicity in soils.

Urea oxidation reaction (UOR) has been identified as a promising method for hydrogen production and the remediation of urea-rich wastewater by electrochemical techniques. In the present work, Ni/C and Ni@Mo₂C(x)/C electrocatalysts (x = 0.1, 0.2, 0.4, and 0.6 mol fraction of Mo₂C in Ni@Mo₂C) are prepared by ball milling method followed by annealing at 800 °C for 2 h under nitrogen atmosphere. Electrooxidation of urea is carried out using these electrocatalysts in an alkaline solution. Among them, the Ni@Mo₂C(0.4)/C catalyst shows a maximum current density of 96.5 mA cm^-2 at 1.7 V (versus RHE) in 1 M KOH and 0.33 M urea electrolyte. The Ni@Mo₂C(0.4)/C catalyst exhibits better catalytic activity, low overpotential, and charge transfer resistance with extremely low Tafel slope compared to other compositions for UOR. The synergistic electronic effect between Ni and Mo₂C components is responsible for generating active sites and facilitating the catalytic activity of UOR. The Ni@Mo₂C(x)/C electrocatalysts are promising for treating urea-rich wastewaters and for use as a substitute for suppressing OER in water-splitting reactions.

Uroglena sp. is a major contributor to the fishy odor in drinking water, with temperature being a key factor regulating its growth. However, no study has yet detailed its effect on Uroglena sp.'s growth. Uroglena sp. mainly blooms in spring when temperatures are lower, though similar lower temperatures are also present in autumn and winter. Therefore, the objectives of this study were to investigate the growth and decline behavior of Uroglena sp. under different temperatures and to assess the impact of microorganism composition in different samples on the growth of Uroglena sp. To achieve the objectives of this study, surface water samples collected in May (spring), September (autumn), and January (winter) were incubated under different temperatures. Findings revealed that Uroglena sp. exhibited higher and more prolonged growth at a low temperature of 5 °C. Within the temperature range of 10 to 20 °C, Uroglena sp. exhibited less vigorous growth and lysed more rapidly. No growth was observed at 30 °C. The limited growth of Uroglena sp. at higher temperatures is attributed to an increased abundance of bacteria and competition with other microalgae including Nitzschia sp., Sphaerocystis sp., Scenedesmus sp., Fragilaria sp., Attheya sp., Golenkinia sp., Melosira sp., and Dinobryon sp. This indicates that the coexistence of microalgae and bacteria plays a significant role in the growth of Uroglena sp. The maximum concentration of Uroglena sp. during incubation was higher for the water sample of May compared to the sample of September and January, which reached about 2500 colony/mL at 5 °C for the sample of May. The generally higher growth of Uroglena sp. with the sample of May suggests that less significant microalgae competition in the season could create more favorable conditions for the bloom of Uroglena sp.

Lake Bosumtwi in tropical Ghana has been known for its recurrent fish kills, but they have recently been reported to happen less frequently. The lake formed in a meteorite impact crater in Ghana, West Africa. It plays an important role for the local inhabitants for recreation and for fisheries. The lake is deep, and recent observations indicate that recirculation is incomplete. In general, the deep water is anoxic. Fish kills have been associated with the mixing events in the slightly colder rainy season. As unpleasant smells from the water during deep mixing had been reported, the question arose whether toxic gases that had accumulated in the deep water could be responsible; namely, hydrogen sulphide or large amounts of carbon dioxide were considered the most probable candidates. The analysis of the water properties, however, did not detect any hydrogen sulphide nor immensely large concentrations of carbon dioxide. On the contrary, the presence of large amounts of bound nitrogen could be substantiated. We hence concluded that most probably bound nitrogen was responsible for the fish kills on two paths (1) as bound nitrogen as ammonium forms toxic ammonia when mixed into high pH surface water and (2) depletes oxygen when it is oxidized in the surface waters.