Iron oxidation and reduction have important effects on soil organic carbon conversion in paddy soil during flooding and dry conditions. This study selected two paddy soil samples, one from the city of Yueyang of Hunan Province and one from the city of Haikou of Hainan Province, that differ significantly in iron content. During a 25-day incubation, the effects of Fe(II) and Fe(III) contents and changes in the levels of several major iron forms on soil dissolved organic carbon (DOC) levels and emission of CH₄ and CO₂ were observed. The ratio of Fe(II) content to all active Fe increased with an increase in Fe(II) content after soil flooding, and the proportion of all active Fe was significantly higher in the soil samples from Yueyang than in those from Haikou. In only 5 days, 92% of Fe(III) was converted to Fe(II) in Yueyang soil samples, and almost all Fe(III) had been transformed into Fe(II) by the end of incubation. Similar behaviors occurred in soil samples collected from Haikou, but Fe(II) represented only 59% of the active Fe by the end of incubation. In total, 2.2 g kg⁻¹ of organic carbon in the Yueyang soil sample was converted to CO₂ and CH₄, and the DOC content increased to 410% of its initial value by the end of incubation. In the Haikou soil, only 0.7 g kg⁻¹ of organic carbon was converted to CO₂ and CH₄, and its DOC content increased to 245% of its initial value by the end of incubation, which was a much smaller increase than observed for the Yueyang sample. Decomposition of organic carbon in the soil was closely related to iron reduction, and reduction of iron in soil significantly affected the conversion rate of organic carbon in soil.

The cultivation of tobacco has serious consequences for the environment: it impoverishes the soil by assimilating its nutrients, it involves an intensive use of highly polluting pesticides, it perturbs the ecosystem through deforestation, and it releases nicotine into the environment, which is toxic for humans. Italy is the first producer of raw tobacco in Europe and the Valtiberina area is among the most profitable. The first cultivations can be reconducted to the period around 1400. The objective of this experimental work is to verify the sustainability of tobacco cultivation near other crops using nicotine as an indicator. The nicotine on medicinal and wild plants adjacent to tobacco crops has been analyzed, assessing whether it is present or not and which is the concentration. To measure the nicotine present with ultra-high-performance liquid chromatography (UHPLC), LC/MS (liquid chromatography-mass spectrometry) method was used with LOQ (quantification limit) of 0.005 mg/kg. A total of 300 lots of aromatic herbs were sampled, and nicotine was detected in 82.3% of the samples in 2015 and 62.9% in 2016. Furthermore, in 2015, 121 samples of wild material were analyzed, of which 88.4% showed traces of nicotine. These first results indicate a possible potential threat for the population health. This shows that the tobacco cultivation should not be in close proximity to other plantation destined for nutrition, neither for man and nor animals. The elevated impact of nicotine on the ecosystem has negative consequences not only for the economy but it is also a potential public health threat.

Insecticidal applications may result to morphological deformations upon exposed insects or their offspring production. In the present study, we tested whether pirimiphos-methyl can induce deformities to wings of progeny production of the invasive khapra beetle, Trogoderma granarium (Coleoptera: Dermestidae) when its parental female adults have been treated with this organophosphorus active ingredient. For that purpose, we analysed both elytra and hindwings of both sexes of T. granarium progeny production by using the geometric morphometrics method. Our results showed that the wings of progeny of the pirimiphos-methyl-treated T. granarium parental female adult individuals suffered certain changes in their usual shape depending on size. Deformations occurred on both pairs of wings, but changes were more noticeable on the hindwings. A longer than 5-h exposure of parental female adults to pirimiphos-methyl, resulted in progeny with more deformed wings than in those individuals emerged after the exposure of their parental female adults in shorter periods on the toxicant. Generally, wings of both sexes were sensitive to pirimiphos-methyl, distinguishing the control group from the insecticidal treatments. The existence of deformed adults could be a useful indicator of earlier insecticidal applications as surface treatments and/or grain protectants in the storage facilities.

The replacement of fossil-based fuels by renewable fuels (biofuels) was proposed in the IPCC report, as an alternative to reduce greenhouse gas emission and reach out to a low-carbon economy. On this perspective, the Brazilian government had implemented a renewable energy program based on the use of ethanol in the transport sector. This work evaluates the scenario of pollutant gas emissions and particulate material that comes from the biomass burning process involved in ethanol production cycle, in the city of Campos dos Goytacazes, Brazil. The gases and particulate material emitted by sugarcane and bagasse burning processes—the last one in energy co-generation mills—were analyzed. A laboratory-controlled burning of both samples was realized in an oven with temperature ramp from 250 to 400 °C, at a regular rate of 50 °C. The gas samples were collected directly from the oven’s exhaust pipe. The particulates obtained were the residual material taken out of the burned samples: a powder with the aspect of soot. A photoacoustic spectroscopy system coupled with quantum cascade laser and electrochemical analyzers was used to measure the emission of polluting gases such as N₂O, CO₂, CO, NOₓ (NO, NO₂), and SO₂ in ppmv range. Fluorescent X-ray spectrometry was applied to evaluate the chemical composition of particulate material, enabling the identification of elements such as Si, Al, Ca, K, Fe, S, P, Ti, Mn, Cu, Zn, Sc, V, Cu, and Sr.

Anthropogenic activities have a significant contribution to groundwater nitrate contamination at multiple spatial scales in urbanizing agricultural catchments, while how to derive the optimal researching scale and explore the relative importance among anthropogenic activities for groundwater nitrate contamination still remains challenging. In this study, 165 perched groundwater and 120 shallow groundwater samples were collected in two urbanizing agricultural catchments, to explore anthropogenic activity effects on groundwater nitrate contamination crossing multiple spatial scales, integrating the probability kriging, multi-scale comparison at spatial scales of 100 to 1900 m with an increment of 200 m at the block scales, and variance partitioning analysis. Probability of perched and shallow groundwater nitrate concentration > 3 mg L⁻¹ exhibited strong spatial autocorrelation, with effective ranges of 1091 m and 3743 m from semivariogram, respectively. Relationships between perched and shallow groundwater nitrate concentrations were more significant and robust (r = 0.30–0.52, p < 0.001) at the block scale from 300 to 1100 m, indicating that perched groundwater nitrate closely related to shallow groundwater nitrate. The responses of groundwater nitrate contamination on anthropogenic drivers presented strongly scaling correlation and had the highest correlation at the spatial scale of 1100 m, suggesting the optimal scale for exploring anthropogenic activity effects on groundwater nitrate contamination. The three categories of anthropogenic drivers (urbanization, agriculture intensification, and demographic driver) contributed to 31.0–84.0% part of the total variations in groundwater nitrate contamination at the spatial scale of 1100 m. Particularly, agriculture intensification was the most influential driver for groundwater nitrate contamination, while the urbanizing process and population growth played important roles surrounding urban cores. Our findings highlighted the importance of incorporating multi-scale comparisons on regional groundwater quality evaluation, and provided technical support to the groundwater resource management strategy development in urbanizing agricultural regions.

Global warming and greenhouse gas emissions have become a severe threat to our ecosystem. Prior studies on environment posit that ample exhaustion of fossil fuels for energy is one of the fundamental causes of environmental degradation and naturally replenished energy sources are affordable over fossil fuels. This study set out to examine the role of financial sectors and globalization (in the presence of energy and renewable energy consumption) for a sustainable environment in the panel of Central and Eastern European (CEE) countries in One Belt and One Road initiative perspective. The current study uses annual data of 16 CEE countries covering the period of 1980 to 2016. After confirmation of cross-sectional dependency and co-integration among variables, we applied the Dynamic Seemingly Unrelated Regression and Dumitrescu–Hurlin causality approach for long-run estimations and to check the causal relationship, respectively. The empirical findings of the study certify the existence of an environmental Kuznets curve for the selected panel countries. Globalization is enhancing the environmental quality of the CEE economies. It is important to note that energy consumption and renewable energy consumption have a positive and statistically significant whack on carbon emission. In addition, we do not find a significant link between financial development and carbon emission. Granger casualty test confirms a two-way causal relationship between economic growth and carbon emission, globalization and environmental degradation, globalization and renewable energy consumption, economic growth and renewable energy consumption, and between financial development and energy consumption. Moreover, we found one-way causality from energy consumption (renewable and non-renewable) to carbon emissions. Based on the findings, a number of appropriate policy suggestions are presented in the perspective of Central and Eastern European Countries.

This study investigates the possible environmental effects of economic openness, such as economic growth, foreign direct investment (FDI) inflows, and trade liberalization in South Asian Association for Regional Cooperation (SAARC) countries. The study employed panel autoregressive lag distribution (ARDL) model to evaluate the environmental effects of economic openness; causality test was also conducted to confirm short- and long-run causality among the variables under discussion. The results show that trade, FDI, capital, and economic growth in the long run have a positive correlation with environmental degradation in SAARC countries while FDI, capital, and trade inflows have a negative relation with CO₂ emissions in the short run. Furthermore, economic growth by creating new job opportunities improved emissions also in the short run. FDI, trade, capital, and GDP have long-run causality with CO₂ emissions. Bidirectional causality was found between GDP and CO₂ emissions, unidirectional causality was also running from FDI inflows to economic growth, unidirectional causality running from capital to FDI and trade to capital. Finally, trade and economic growth also have unidirectional causality in the short run. This study concludes, therefore, that SAARC countries should invest in green energy and promote green trade liberalization.

Intrusion of seawater into the coastal aquifers is a major concern as it affects the quality of groundwater. The objective of this study is to delineate the extent of seawater intrusion in the Indian coast based on previous studies and estimate the area as well as locations of seawater intrusion and submarine groundwater discharge based on the groundwater level of the years 2007 and 2017. Several researchers have reported seawater intrusion in the coastal regions of India by different methods of investigation. These studies indicate that the east coast of India is affected greater than the west coast by seawater intrusion. The maximum extent (about 14 km) of seawater intrusion in India is reported in regions north of Chennai. It is estimated that around 7% of the total coastal area is affected by seawater intrusion, where groundwater is below mean sea level. Around 57% of the coastal area of India has groundwater level in the range from 0 to 10 m msl. Future research needs to focus on the areas where seawater intrusion and submarine groundwater discharge were identified based on this study.

The impacts of biofouling on the retention of pharmaceutically active compounds (PhACs) by a commercially available nanofiltration membrane (NF 270) were systematically studied. Biofouling was achieved through inoculating live and dead Pseudomonas aeruginosa into artificial wastewater. In comparison to a clean membrane, an increase in PhAC rejection during biofouling with live cells was observed. However, the rejection behaviors presented more complex changes during biofouling with dead cells: PhAC rejection was below the clean membrane in the early biofouling stage; however, in the later stage, PhAC rejection was above the clean membrane. In addition, PhAC rejection behaviors present the similar tendency as salt rejection under both biofouling conditions. In addition, solute rejections were much lower for biofouling with dead cells than those for biofouling with live cells. Combined with biofilm characterization under both biofouling conditions, we could conclude that biofilm enhanced osmotic pressure (BEOP) due to higher cell counts and biofilm thickness led to a decrease in PhAC retention, especially for the dead cells. In addition, more dominant steric exclusion in the later stage of biofouling due to higher extracellular polymeric substances (EPS) concentration on the membrane surface resulted in an increase in PhAC retention.

With the widespread use of metal oxide nanoparticles (MNPs), agricultural soil is gradually becoming a primary sink for MNPs. The effect of these nanoparticles on the fate and the toxicity of co-existing heavy metals is largely unknown. In this paper, pot experiments were conducted to evaluate the impact of ZnO nanoparticles (ZnO-NPs) on Cd toxicity and bioaccumulation in a soil-rice system. Different amounts of ZnO-NPs were added to three different levels of Cd-contaminated paddy soil (L-Cd, 1.0 mg kg⁻¹; M-Cd, 2.5 mg kg⁻¹; H-Cd, 5.0 mg kg⁻¹). The results showed that the addition of ZnO-NPs significantly increased the soil pH value, and the soil pH value increased with the increase in ZnO-NP concentration. Reductions in plant height and biomass under Cd stress were recovered and increased after the addition of ZnO-NPs; the addition of ZnO-NP promoted rice biomass increased by 13~22% and 25~43% in the M-Cd and H-Cd groups, respectively, compared with that of the respective control treatment. A high concentration of ZnO-NPs could increase the concentration of bioavailable Cd in rhizosphere soil. In the L-Cd group, the Cd concentration of the rice in the L-Z500 treatment increased to 0.51 mg kg⁻¹, exceeding the limit for acceptable Cd concentrations in rice of China (0.2 mg kg⁻¹). This work revealed that ZnO-NPs could improve plant growth, especially in the early-growth stage, and alleviate the toxic effects of Cd. However, the addition of high-concentration (500 mg kg⁻¹) ZnO-NPs in the lower Cd pollution soil could significantly facilitate the accumulation of Cd by Oryza sativa L.