Nanoparticles (NPs) have been progressively applied in the last decades, which may impact the environment. Synthesis of pigments, growing, and nutrient element uptake by plants can also be affected by NPs. The influence of lanthanum oxide nanoparticles (La₂O₃ NPs) on growth, pigment synthesis, and nutrient element uptake by Pfaffia glomerata (Spreng.) Pedersen, a medicinal plant native in South America, was evaluated in the present study. P. glomerata plantlets were cultivated for 28 days in the absence (control) and presence of 100, 200, and 400 mg L⁻¹ of La₂O₃ NPs or bulk-La₂O₃ (b-La₂O₃) at the same cultivation conditions. Root development, aerial part growth, and pigment concentration in plants were affected by b-La₂O₃ and La₂O₃ NPs, mainly by La₂O₃ NPs. In spite of alteration of nutrient element concentration observed for the 100 and 200 mg L⁻¹ of La₂O₃ NPs or b-La₂O₃ treatments, Ca, Cu, Fe, K, La, Mg, Mn, Mo, P, S, and Zn determination in stems and leaves revealed drastically and similar decrease of these elements in plants cultivated in the presence of 400 mg L⁻¹ of La₂O₃ NPs or b-La₂O₃. Element distribution (mapping) determined by using laser ablation inductively coupled plasma mass spectrometry in leaves of plants submitted to treatment with 400 mg L⁻¹ of b-La₂O₃ or La₂O₃ NPs showed differences in the distribution of elements, indicating distinct effects of b-La₂O₃ and La₂O₃ NPs on P. glomerata. As such, this study demonstrated that La₂O₃ NPs may impact plant growth. However, more investigations are necessary for better understanding of the effect of La₂O₃ on plants, including a broader range of concentration.

Ecological vulnerability has become one of the hot issues of ecology and environmental science under global change and sustainable development scenarios. However, no study quantitatively analyzes the global scientific performance and hot research areas in this field by adopting the bibliometric method. Based on 935 pieces of literature retrieved from the Web of Science database, we comprehensively analyzed the research on ecological vulnerability in terms of growth trend, research content, publication journal and country, and co-occurrence network of keywords. The results showed that research on ecological vulnerability had experienced rapid growth since 2000, while ecological vulnerability research at the World Heritage sites was still embryonic. The top two productive countries in ecological vulnerability research were America and China, and the top two productive journals were Ecological Indicators and Regional Environmental Change. Study on ecological vulnerability was mainly classified as empirical evaluation and regional synthesis, whereas theoretical research is rare. Based on the summary of the main progress and achievements in ecological vulnerability research, we proposed five scientific issues that remain to be resolved in the field of ecological vulnerability. Overall, this study could shed light on a comprehensive and systematic understanding of ecological vulnerability and provide directions for future research on ecological vulnerability in a rapidly changing world.

Water pollution is considered an acute worldwide environmental issue. At present, the commonly adopted method of water quality characterisation involves the retrieval of optically active water quality parameters based on remote sensing reflectance (Rᵣₛ), but this method is subject to the limitation that understanding local scatter and absorption characteristics of light is essential to precisely derive these parameters. Water colour primarily depends on water constituents and is traditionally gauged with the Forel–Ule (FU) scale. In recent years, Rᵣₛ within the visible region has been considered to determine the Forel–Ule Index (FUI) for water colour measurement. The FUI exhibits the advantages of remote sensing and does not rely on local retrieval algorithms. Therefore, this index can characterise natural waters in a simple and globally effective manner. As there exists a lack of review articles on the FUI, we present a comprehensive review of this index that may help researchers progress. First, we introduce the most recent techniques for FUI measurement, especially remote sensing–deriving methods. Then, we summarise FUI applications in water quality assessment of oceans and inland waters. Finally, FUI development trends, challenges and application perspectives are examined.

To further explore the development of construction waste recycling enterprises and promote the recycling of construction waste resources in China, a system dynamics model of the economic benefits of construction waste recycling enterprises is established using the system dynamics method and taking the tax incentive of the Guangzhou Municipal Government as an example. The economic benefits of construction waste recycling enterprises are analyzed from the perspective of the total cost, total revenue, and total recycling amount. The results of the MATLAB simulation and numerical analysis show that (1) by simulating the effects of different taxes such as value-added tax (VAT), education surcharge, urban construction tax, and enterprise income tax on the economic benefits of construction waste recycling enterprises, it is found that when tax incentives reach 70%, the VAT favorable policies bring the highest gains, followed by enterprise income tax, whereas favorable education surcharge policies and urban construction tax have the least impact on economic benefits. (2) Taking the monetary subsidy of the Guangzhou municipal government as an example, it is estimated that the total revenue of construction waste recycling enterprises will increase by 33.56% annually in 2030. When the new production technology is adopted, the return on investment (ROI) will reach 46.8% in 2030 compared to previous technological improvements. In the simulation scenario, the ROI will be 42.2%, which has a good incentive effect on the cost control of enterprises. (3) Increasing the available power to VAT and corporate income tax can improve the profitability of construction waste recycling enterprises in China; however, tax incentive policy will no longer be the main factor affecting the benefits of enterprises when a certain time is reached. (4) It is suggested that the government improves the relevant tax laws incentive policies, increase tax incentives, and add equipment tax incentive policies, actively change the tax mode, and increase indirect tax models to improve the economic benefits of enterprises. The research results provide a decision-making reference for the government to formulate laws and policies related to the economic benefits of construction waste recycling and promote the development of the construction waste recycling industry, the development of new industries, such as waste recycling and treatment, and the formation of industrial chains, to achieve the strategic goal of sustainable development.

The policy of the national smart city (NSC) pilots, a new type of urbanization for future development, has been implemented in China in batches. This paper investigates the mechanism and effects of the NSC pilots on the environment. Using the prefecture-level panel data during 2004–2018 period, our multi-period difference-in-differences (DID) estimation shows that the NSC pilots causally mitigate SO₂ (wastewater) pollution by 13.76% (14.36%), which is supported by a series of robustness tests. The mediating effect model indicates that green total factor productivity (GTFP) plays a partial mediating role in mitigating both SO₂ and wastewater emissions, while technological innovation plays a partial mediating role in mitigating wastewater emissions. After introducing the two mediating channels into the multi-period DID model, the reduction effect for SO₂ and wastewater emissions drops to 11.04% (1-e⁻ ⁰.¹¹⁷) and 12.1% (1-e⁻ ⁰.¹²⁹), respectively. Comparatively, the NSC pilots contribute to the improvement of GTFP and GTFP takes the major mediating role in reducing SO₂ and wastewater pollution. The heterogeneous effects of the NSC pilots show that the mitigation effect is more pronounced in cities with strong fiscal support, cities with abundant human capital, and cities with high R&D expenditure. Based on these novel findings, this study provides some policy implications for achieving better mitigation effects.

Preservative treatments increase the durability of wood, and one of the alternative treatments involves the use of chromated copper arsenate (CCA). Due to the toxicity of CCA, the disposal of CCA-treated wood residues is problematic, and burning is considered to provide a solution. The ecotoxicological potential of ash can be high when these components are toxic and mutagenic. The aim of this study was to evaluate the toxicity and genotoxicity of bottom ash leachates originating from CCA-treated wood burning. Physical-chemical analysis of the leachates revealed that in treated wood ashes leachate (CCA-TWBAL), the contents of arsenic and chromium were 59.45 mg.L⁻¹ and 54.28 mg.L⁻¹, respectively. In untreated wood ashes leachate (UWBAL), these contents were 0.70 mg.L⁻¹ and 0.30 mg.L⁻¹, respectively. CCA-TWBAL caused significant toxicity in Lactuca sativa, Allium cepa, and microcrustacean Artemia spp. (LC50 = 12.12 mg.mL⁻¹). Comet assay analyses using NIH3T3 cells revealed that concentrations ranging from 1.0 and 2.5 mg.mL⁻¹ increase the damage frequency (DF) and damage index (DI). According to MTT assay results, CCA-TWBAL at concentrations as low as 1 mg.mL⁻¹ caused a significant decrease in cellular viability. Hemolysis assay analyses suggest that the arsenic and chromium leachate contents are important for the ecotoxic, cytotoxic, and genotoxic effects of CCA-TWBAL.

We investigated the effects of fine particulate matter from hydrothermal ore on the physiological and molecular responses of the marine copepod Tigriopus japonicus. We evaluated its life cycle parameters including survival, development, and fecundity and the transcriptional profiles of its genes regulating detoxification (cytochrome P450 [CYP]), antioxidation (glutathione S-transferase [GST]), and development (vitellogenin [Vtg]) in response to hydrothermal ore and beneficiation leachates. There were preponderances of copper, iron, and zinc in the hydrothermal ore and the leachates derived from it. There were no significant changes in copepod developmental time in response to leachate exposure. However, copepod survival and fecundity significantly changed in response to the leachates. Moreover, the transcriptional profiles of the detoxification, antioxidation, and development-related genes were significantly modulated following leachate treatment. Hence, hydrothermal ore and beneficiation leachates promoted the transcriptional expression of detoxification, antioxidation, and development-related genes and altered survival and fecundity in T. japonicus. The results of the present study may help to assess the potential impacts of ore mining, mineral extraction, and beneficiation on the physiological and molecular responses of marine organisms.

In this study, the azo dye acid orange 7 (AO7) was degraded by synergistic activation of persulfate (PMS) with cyclohexanone/chloride ion (Cl⁻). The effects of cyclohexanone dosage, PMS concentration, Cl⁻ concentration, initial pH, temperature, and aqueous natural organic matter (NOM) on the AO7 removal were investigated. Under alkaline conditions, the removal rate of AO7 increased with increasing cyclohexanone and Cl⁻ concentrations. The degradation rate of AO7 was unaffected by the water matrix and NOM in the environment. As shown in radical quenching experiments and electron paramagnetic resonance spectroscopy analysis, the main reactive species generated in the reaction system were hypochlorous acid (HCIO) and singlet oxygen (ˡO₂), which destroyed the azo bond and naphthalene ring structure in AO7. Judging from its ability to degrade AO7, the cyclohexanone/Cl⁻/PMS system is suitable for treating high-salt wastewater containing organic pollutants.

In this study, the contents of microcystin-LR (MC-LR) of Microcystis aeruginosa cultures in the laboratory and natural water samples from the Huangpu River in different seasons were detected through enzyme-linked immunosorbent assay (ELISA) and high-performance liquid chromatography (HPLC), respectively. Excellent correlation between the two methods was obtained (R² > 0.99). ELISA was a reliable and simple method with high reproducibility (coefficient of variation < 25%) and satisfactory recovery for the monitoring of low levels of MC-LR. MC-LR concentrations in Huangpu River varied with the seasonal variation, which peaked in August with the temperature over 30 °C and then gradually declined with the decreasing temperature after August. The highest MC-LR concentration in the Huangpu River was below the WHO drinking water quality standard (1 µg/L). These results indicated that warm temperature accelerated the MC-LR synthesis and release, and it is necessary to regularly monitor the MC-LR levels, especially during the high algae period in summer. ELISA can be applied to detect the low levels of MC-LR in the field without complex treatment, avoiding the samples from denaturation and degradation during the transportation. Hence, ELISA is a better alternative of HPLC when HPLC is unavailable, especially when rapid testing is required in routine MC-LR analysis.