There is increasing evidence that titanium dioxide (TiO₂) nanoparticles (NPs) present in water or diet can be taken up by fish and accumulate in internal organs including the liver. However, their further fate in the organ is unknown. This study provides new insights into the interaction, uptake mechanism, intracellular trafficking, and fate of TiO₂ NPs (Aeroxide® P25) in fish liver parenchymal cells (RTL-W1) in vitro using high-resolution transmission electron microscopy (TEM) and single particle inductively coupled plasma mass spectrometry (spICP-MS) as complementary analytical techniques. The results demonstrate that following their uptake via caveolae-mediated endocytosis, TiO₂ NPs were trafficked through different intracellular compartments including early endosomes, multivesicular bodies, and late endosomes/endo-lysosomes, and eventually concentrated inside multilamellar vesicles. TEM and spICP-MS results provide evidence that uptake was nano-specific. Only NPs/NP agglomerates of a specific size range (~ 30–100 nm) were endocytosed; larger agglomerates were excluded from uptake and remained located in the extracellular space/exposure medium. NP number and mass inside cells increased linearly with time and was associated with an increase in particle diameter suggesting intracellular agglomeration/aggregation. No alterations in the expression of genes regulated by the redox balance-sensitive transcription factor Nrf-2 including superoxide dismutase, glutamyl cysteine ligase, glutathione synthetase, glutathione peroxidase, and glutathione S-transferase were observed. This shows that, despite the high intracellular NP burden (~ 3.9 × 10² ng Ti/mg protein after 24 h) and NP-interaction with mitochondria, cellular redox homeostasis was not significantly affected. This study contributes to a better mechanistic understanding of in vitro particokinetics as well as the potential fate and effects of TiO₂ NPs in fish liver cells.

A field survey was conducted to investigate metal(loid) concentration in soils and native plants in the Baoshan mining area for potential application in phytoremediation. Total concentrations of arsenic (As), cadmium (Cd), lead (Pb), and zinc (Zn) in soil varied from 125 to 6656, 5.10 to 1061, 568 to 49294, and 241 to 17296 mg kg⁻¹, respectively, showing severe contamination. Among 20 species native to this area, Pteris ensiformis accumulated 1091 mg kg⁻¹ As in the shoot, and its translocation factor (TF) was greater than 1, suggesting potential capacity for As phytoextraction. Boehmeria nivea, Aster prorerus, and Hydrocotyle sibthorpioides showed potential for phytoextraction of Cd due to their high accumulation of Cd in shoots (490.3, 175.4, and 128.5 mg kg⁻¹, respectively) and high TFs (92.0, 22.1, and 6.7, respectively). Eleusine indica and P. ensiformis were found to contain high concentrations of Pb (7474 mg kg⁻¹) and Zn (1662 mg kg⁻¹) in roots, but with low TFs for Pb (0.4) and Zn (0.2), suggesting potential capability for phytostabilization. There was a positive correlation (p < 0.01, N = 25) of TFs between the metal(loid)s, indicating a synergic interaction in the uptake of metal(loid)s by these plants. According to metal(loid) concentrations in shoots, bioconcentration factors (BFs), and TFs, as well as the botanical features such as wide occurrence, high biomass yield, and rapid growth of the plants, the five native species identified above have the potential for phytoremediation in the Baoshan mining area.

The original publication of this paper contains a mistake. The correct University name of the 3rd affiliation is shown in this paper.

Efficient abatement of an iodinated X-ray contrast media iohexol by an emerging sulfite autoxidation advanced oxidation process is demonstrated, which is based on transition metal ion–catalyzed autoxidation of sulfite to form active oxidizing species. The efficacy of the combination of sulfite and transition metal ions (Ag(I), Mn(II), Co(II), Fe(II), Cu(II), Fe(III), or Ce(III)) was tested for iohexol abatement. Co(II) and Cu(II) are proven to show more pronounced catalytic activity than other metals at pH 8.0. According to the quenching studies, sulfate radical (SO₄•⁻) is identified to be the primary species for oxidation of iohexol. Increasing dosages of metal ion or sulfite and higher pH values are favorable for iohexol abatement. Inhibition of iohexol abatement is observed in the absence of dissolved oxygen, which is vital for the production of SO₅•⁻ and subsequent formation of SO₄•⁻. Overall, activation of sulfite to produce reactive radicals with extremely low Co(II) or Cu(II) concentrations (in the range of μg L⁻¹) in circumneutral conditions is confirmed, which offers a potential SO₄•⁻-based advanced oxidation process in treatment of aquatic organic contaminants.

Under flooded conditions in paddy soil, the mobility of As increases while the mobility of Cd decreases. The opposite geochemical behavior of As and Cd makes it difficult to reduce their mobilities simultaneously. Our recent study found that combined applications of biochar and zero-valent iron successfully reduced the mobilities of As and Cd simultaneously. On this basis, in the present study, an iron-modified biochar (Fe-BC) was developed, and its effect on decreasing the accumulations of As and Cd in rice was verified in a 2-year field trial. In addition, previous studies indicated that silicon fertilizer can also reduce As and Cd accumulation in rice grain. Hence, the effect of the combined or separate application of Fe-BC and silica sol on As and Cd accumulation in rice grain was investigated. Over the 2-year field trial, the grain yields decreased in the following order: iron-modified biochar plus silica sol (Fe-BC plus Si) > silica sol (Si) > Fe-BC > control (CK). Concentrations of As and Cd in brown rice were in the order: Fe-BC plus Si < Si ≈ Fe-BC < CK. The treatments of Fe-BC and Fe-BC plus Si significantly increased the soil pH and thus decreased available As and available Cd in the soil. In addition, significantly positive correlations between available As and As in brown rice and between available Cd and Cd in brown rice were found. In conclusion, co-application of iron-modified biochar and silica sol should be a recommended strategy to reduce the accumulation of As and Cd in rice grains.

Se can regulate Cd accumulation and translocation in plants; however, such effects can be controversial because of the differences in plant species and Se species. In this study, pak choi was cultured under hydroponic conditions, and the effects of selenite and selenate on Cd accumulation were investigated in the edible parts of this vegetable. The results showed gradual improvements in the effects of the two Se species on the Cd content in pak choi shoots at the four assessed growing stages. Selenite did not lead to significant changes in Cd accumulation in the shoots until day 40, when it significantly reduced the accumulation by 34%. Selenate was always found to increase the Cd content in the shoots, and the differences on days 19 and 40 were 16% and 45%, respectively, compared with those of the Cd (only) treatment. Accordingly, selenate invariably enhanced Cd translocation from the roots to the shoots, whereas selenite insignificantly reduced the translocation only on day 40. Generally, selenomethionine (SeMet) accounted for much larger proportions in selenite-treated plants, while SeO₄²⁻ was the dominant Se species in selenate-treated plants. However, under both Se treatments, the SeMet proportion increased substantially from day 19 to day 40 when that of SeO₄²⁻ exhibited a drastic decrease; therefore, the relative proportion of seleno-amino acids to SeO₄²⁻ may be the key factor for the regulation of Cd accumulation in pak choi via treatment with selenite and selenate at the different growing stages.

In the present work, an experimental investigation was conducted to study the influence of adding aluminum oxide nanoparticles (Al₂O₃) with different average particle sizes as additive to blends of diesel and waste plastic oil (WPO) on performance, emission, and combustion attributes of single-cylinder diesel engine operated at a constant speed. Two samples of Al₂O₃ nanoparticle with average particle sizes of 20 and 100 nm were dispersed into a WPO20 blend containing 20% of WPO and 80% of diesel in the mass fractions of 10 and 20 ppm using ultrasonic stabilization. The experimental recordings revealed a decrease in engine performance and increase in all emission constituents while replacing diesel with WPO20. However, the addition of both 20- and 100-nm-sized Al₂O₃ nanoparticles into WPO20 was found to enhance the brake thermal efficiency (BTHE) by 12.2 and 8.9% respectively and decrease the brake-specific fuel consumption (BSFC) by 11 and 8% respectively. The emission constituents such as carbon monoxide (CO), hydrocarbons (HC), nitric oxide (NO), and smoke opacity were minimized by the addition of both 20- and 100-nm-sized nanoparticles into WPO20 blend. However, the reduction of emissions was better for 20-nm-sized particles compared with that of 100-nm-sized particles. The combustion attributes such as cylinder pressure, heat release rate (HRR), and rate of pressure rise (RPR) were raised with shortened ignition delay (ID) by the addition of both sized nanoparticles. Overall, the inclusion of 20-nm-sized nanoparticles performs better catalytic activity to enhance the engine output characteristics along with minimum exhaust emissions.

Micro(nano)plastics, new emerging contaminants, are ubiquitously found in the environment due to continuous release and accumulation. Widespread micro(nano)plastics can increase their exposure to organisms, pose threats to the ecological environment and human health, and potentially result in global biodiversity changes. Research has been started on micro(nano)plastics regarding their environmental distribution, contamination sources, and methods and technologies for analysis, as well as the environmental impacts and ecological effects on organisms ingesting micro(nano)plastics. However, limited information focused on the consequences of global biodiversity has been reported and the research approaches on biodiversity change caused by micro(nano)plastics are still seldom developed. Recently, researchers in environmental and ecological groups have begun to be conscious of the relationship between micro(nano)plastics and biodiversity. Even so, more efforts are needed to assess the impacts of micro(nano)plastics on this subject, as well as the interactions between organisms and micro(nano)plastics.

Hexachlorobenzene (HCB) dechlorination affected by humic acids (HA) was evaluated in terms of HA redox capacity, HA concentrations, and microbial community, as well as the correlation between HA redox capacity values and HCB concentrations. With addition of HA in the initial stage, redox capacity values increased by 2.19 meq/L (80 mg/L of HA addition, HA₈₀), 2.51 meq/L (120 mg/L of HA addition, HA₁₂₀), and 3.64 meq/L (200 mg/L of HA addition, HA₂₀₀), respectively. The addition of HA could prominently enhance the HCB degradation rate. However, the concentration and the redox capacity of HA decreased during the anaerobic digestion process. Illumina MiSeq sequencing showed that microbial community affected by HA. Bacillus, Comamonas, and Pseudomonas were the predominant genera during the HCB dechlorination treatment. Moreover, Bacillus and Pseudomonas can improve HA electron transfer capability and promote the dechlorination of HCB.

Green behavior is an important part of the study of green development. To promote green development, it is necessary to engage in further innovation on the basis of lessons from international advancements in green behavior. To clarify the spatial and temporal distribution characteristics of international researchers in the study of green behavior, the research focus, and the research frontiers, a visual analysis was performed on 22,114 articles cited in the SSCI and SCI-EXPANDED databases from 2000 to 2017. This analysis was based on bibliometrics and mapping knowledge domain (MKD) analysis with CiteSpace 5.3.R4, a scientific and technological text-mining and visualization software. The results show that international green behavior research has the following main characteristics. First, a positive correlation was found between the number of papers and time. Second, research is highly valued by researchers in the natural sciences, such as ecology. The USA is involved in major research efforts and maintains a high level of cooperation with other countries and regions. International cooperation among institutions needs to be strengthened. The co-cited journals are primarily academic journals in the natural sciences. Third, research hotspots mainly focus on the theory of planned behavior (TPB), consumers, attitudes, performance, and environment, all of which evolve according to the phase path of “germination-growth.” Fourth, the research frontier issues are largely related to management science and environmental science, and the research objects and methods will become increasingly complex and interdisciplinary over time.