The present paper discusses a novel methodology based on neural network to determine agriculture emission model simulations. Methane and nitrous oxide are the key pollutions among greenhouse gases being a major contribution to climate changes because of their high potential global impact. Using statistical clustering (k-means and Ward’s method), five meaningful clusters of countries with similar level of greenhouse gases emission were identified. Neural modeling using multi-layer perceptron networks was performed for countries placed in particular groups. The parameters that characterize the quality of a network are the predictive errors (mainly validation and test) and they are high (0.97–0.99). The use of sensitivity analysis allowed for identifying the variables that have a significant influence on the greenhouse gases emissions. The sensitivity analysis of the designed artificial neural network models shows a few dominant variables, affecting emissions with varied intensity: cattle and buffaloes, sheep and goat populations, afforestation as well as electricity consumption. The observed values were compared with those predicted by the models. The forecasted course of changes in the variable test is identical with the real data, which proves that the model highly matches to the observed data.

In this work, an advanced oxidation process using ozonation combined with hydrogen peroxide (H₂O₂) and catalyzed by manganese (Mn²⁺) in alkaline conditions was investigated to degrade the organic matter present in a synthetic dairy wastewater (SDW) with a chemical oxygen demand (COD) of 2.3 g L⁻¹. The effect of independent factors such as pH (7–13), H₂O₂/O₃ ratio (0–1), and Mn²⁺ concentration (0–1.71 g L⁻¹) has been evaluated and the process optimized using a factorial design and a central composite design (CCD) in sequence. The experiment has been made in batch trials using 2 L of SDW in which ozone was bubbled during 2 h and samples collected for COD analyses, used as response variable. In the factorial experiment, the effect of H₂O₂ was not significant for all the ratios tested (p value > 0.10), and the effects of the pH and Mn²⁺ were positive and significant (p value ≤ 0.05). In the CCD, the linear (positive) and quadratic (negative) effects of pH and Mn²⁺ were significant (p values ≤ 0.05 and ≤ 0.10, respectively). According to the response optimizer, the optimal condition for the ozonation catalyzed by manganese at alkaline medium (COD removal of 69.4%) can be obtained in pH 10.2 and Mn²⁺ concentration of 1.71 g L⁻¹. Moreover, COD removals above 60% can be obtained for pH values of 9.5 to 11 and Mn²⁺ concentrations of 0.6 g L⁻¹.

The layered double hydroxides (LDHs) with a hydrotalcite-like structure are believed to possess great potentials as environmental remediation materials including removal of heavy metals from aqueous solutions by adsorption. A new LDH was synthesized with Mg²⁺ as the structure-stabilizing ion (FeMnMg-LDH) based on a co-precipitation method, which showed promised adsorption capacity for Pb. Its adsorption characteristics for Cd²⁺, an environmental active element relative to Pb, were examined in this paper. The results showed that adsorption equilibria were well described by Langmuir isotherm and the adsorption kinetics well followed a pseudo-second-order kinetic model. The maximum Cd²⁺ adsorption capacity of FeMnMg-LDH was about 59.99 mg/g at 25 °C, which is significantly higher than that of other similar kinds of absorbents. The high Cd²⁺ removal efficiency could maintain at a wide pH range due to its buffering capacity. The coexisting cations competed with Cd²⁺ adsorption on the FeMnMg-LDH with a sequence of Cu²⁺ > Pb²⁺ > Mg²⁺ > Ca²⁺ when coexisting ions were added in the adsorption system separately. The positive value of ΔH° (14.016 kJ/mol) suggested that the adsorption process is endothermic while the positive ΔS° value (0.08 kJ/mol K) revealed that the randomness increased at the solid-solution interface during the adsorption process. FeMnMg-LDH removes Cd²⁺ from aqueous solution mainly by surface adsorption, surface-induced precipitation, and ion exchange. The FeMnMg-LDH has been further proved to be a good absorbent for the removal of heavy metals from aqueous solution.

In order to evaluate the health of Plicopurpura pansa, a species considered vulnerable, a population of this gastropod living in proximity to the port of greatest cargo movement in Mexico was monitored seasonally during 1 year. Morphometric characteristics and sexual proportion were recorded. A macroscopic analysis was carried out to detect malformations and imposex; a histological analysis was performed to evaluate disseminated and gonadal neoplasias; the presence/absence in soft tissues of butyltin species (BTs) as possible contamination agents was also estimated. A total of 508 P. pansa specimens were collected. The largest specimens were obtained in winter. The coefficients of determination inside the port were low (R² = 0.453). In general, there was a greater proportion of females than males throughout the year. Distinctive foot malformations (tumors) were recorded, but without signs of imposex. The histological examination confirmed the presence of disseminated neoplasias in the foot and gonads of P. pansa in the Port of Manzanillo. The comparative analysis of the morphological and histological features of the studied gastropod population allowed us to recognize impact patterns in relation to proximity to the port. There were high concentrations of monobutyltin (MBT) and greater abundance of tumors in heavier specimens; this was associated with port proximity zones. P. pansa could therefore serve as a sensitive bioindicator of environmental health in marine systems.

River quality trajectories are presented for (i) organic pollution, (ii) eutrophication, (iii) nitrate pollution, and (iv) metal contamination over the Longue Durée (130 to 70 years). They are defined by a quantified state indicator (S) specific to each issue, compared to drivers (D) or pressures (P) and to social responses (R) that reflect the complex interactions between society and river quality. The Lower Seine River, naturally sensitive to anthropogenic pressures, greatly impacted by Paris urban growth, industrialization, and intensive agriculture, and well documented by the PIREN-Seine 25-year research program, was chosen to illustrate these trajectories. State indicators, dissolved oxygen, algal pigments, nitrate, and heavy metals (Cd, Cr, Hg, Pb, Zn) in sediments have only been monitored by river basin authorities since 1971. Therefore, their past changes have been reconstructed using three approaches: (i) reassessment of historical sources, (ii) pressure-state models that reconstruct past water quality, and (iii) sedimentary archives of past persistent contamination from dated floodplain cores. The indicators were then transformed into river quality status using contemporary water quality criteria throughout these records. Each environmental issue shows specific trajectories because each has its own relationship between the issue evidence and the social response, but all are characterized by very poor quality in the past, largely ignored: the long-term summer hypoxia (<1880–1995), the summer eutrophication peak (1965–2005), the growing nitrate level since the 1950s, recently stabilized but still high, and the extreme metal contamination (>1935–2000) that peaked in the 1960s. The efficiency of social responses has been highly variable but more efficient in the last 15–25 years.

The removal efficiency and tolerance of Typha domingensis to Cr(VI) in treatments with and without organic matter (OM) addition were evaluated in microcosm-scale wetlands. Studied Cr(VI) concentrations were 15 mg L⁻¹, 30 mg L⁻¹, and 100 mg L⁻¹, in treatments with and without OM addition, arranged in triplicate. Controls (without neither metal nor OM addition—without metal with OM addition) were disposed. Cr(VI) was removed efficiently from water in all treatments. OM addition enhanced significantly Cr(VI) and total Cr removals from water. In the treatments with OM addition, significantly higher Cr concentrations were found in sediment than the treatments without OM addition. Plants of the treatments without OM addition showed significantly higher Cr concentrations in tissues but lower biomass increase than the treatments with OM addition. The highest Cr concentrations in tissues were observed in submerged parts of leaves, followed by roots. According to SEM analysis, in the 100 mg L⁻¹ treatments, the highest Cr accumulation was observed in the epidermis of old leaves. Although Cr(VI) produced changes in root morphology, the OM addition favored the plant growth. In T. domingensis, root morphological plasticity is an important mechanism to improve metal tolerance and Cr uptake in wetland systems minimizing the environmental impact.

As one of the most active components in soil, bacteria can affect soil physicochemical properties, its biological characteristics, and even its quality and health. We characterized dynamics of the soil bacterial diversity in planted (with Taxodium distichum) and unplanted soil in the riparian zone of the Three Gorges Dam Reservoir (TGDR), in southwestern China, in order to accurately quantify the changes in long-term soil bacterial community structure after revegetation. Measurements were taken annually in situ in the TGDR over the course of 5 years, from 2012 to 2016. Soil chemical properties and bacterial diversity were analyzed in both the planted and unplanted soil. After revegetation, the soil chemical properties in planted soil were significantly different than in unplanted soil. The effects of treatment, time, and the interaction of both time and treatment had significant impacts on most diversity indices. Specifically, the bacterial community diversity indices in planted soil were significantly higher and more stable than that in unplanted soil. The correlation analyses indicated that the diversity indices correlated with the pH value, organic matter, and soil available nutrients. After revegetation in the riparian zone of the TGDR, the soil quality and health is closely related to the observed bacterial diversity, and a higher bacterial diversity avails the maintenance of soil functionality. Thus, more reforestation should be carried out in the riparian zone of the TGDR, so as to effectively mitigate the negative ecological impacts of the dam. Vegetating the reservoir banks with Taxodium distichum proved successful, but planting mixed stands of native tree species could promote even higher riparian soil biodiversity and improved levels of ecosystem functioning within the TGDR.

The global energy landscape has significantly changed in the past several years because horizontal drilling and hydraulic fracturing enable unconventional oil and gas extraction from previously inaccessible shale formations. However, opportunities and challenges coexist. Large volumes of freshwater consumed and wastewater discharge increasingly affect the environment and ecosystem. Much freshwater is pumped into deep formations during hydraulic fracturing process, and flowback with high-salinity brines, producing large volumes of wastewater. Such wastewater contains not only many toxic chemicals and high levels of total dissolved solids, but also abundant stratigraphic minerals and radioactive substances, which may pose a serious risk to the surrounding environment and public health. One of the greatest challenges for current oil and gas extraction is handling those wastewaters in a reasonable and efficient way. This paper described the current methods for dealing with these challenges and put forward some suggestions and expectations for future management of water resources in hydraulic fracturing. Graphical Abstract

Exposure to divalent nickel [Ni(II)] poses a significant risk to human health. The present study was conducted to evaluate the biosorption capacity of acorn shell of Quercus crassipes Humb. & Bonpl. (QCS) for removal of Ni(II) ions from aqueous solutions in terms of kinetics, equilibrium, and thermodynamics. Batch biosorption studies showed that the Ni(II) biosorption behavior of QCS is strongly dependent on solution pH, shaking contact time, initial Ni(II) concentration, and temperature. Specifically, Ni(II) biosorption was found to increase with increasing solution pH, contact time, initial Ni(II) concentration, and temperature. Modeling of the Ni(II) biosorption kinetic and equilibrium data showed that the best agreement of experimental data was achieved with the pseudo-second-order kinetics model and the Freundlich isotherm model, respectively. The calculated thermodynamic parameters indicated that the Ni(II) biosorption process was endothermic, non-spontaneous, and chemical in nature. Fourier-transform infrared (FTIR) spectroscopy analysis showed that acidic functional groups, namely hydroxyl, carbonyl, and carboxyl functional groups, present on the QCS surface are likely to be involved in the biosorption of Ni(II) ions. The performance of QCS was compared with those of other reported biosorbents in terms of the efficiency of Ni(II) removal from aqueous solutions, revealing that QCS is highly effective in terms of its biosorption capacity. These findings indicate that QCS can be used as a low-cost, highly effective, and environmentally friendly alternative biosorbent for the detoxification of Ni(II)-contaminated water and wastewater.

Agricultural fungicide application in Argentina has increased twice since 2008, with Maxim® XL (2.5% fludioxonil +1% metalaxyl-M) as one of the most used fungicide formulation. The toxicity of this pesticide on Rhinella arenarum was assessed by means of continuous (from embryo and larval development) and 24-h pulse exposure standardized bioassays. Lethality was concentration- and exposure time-dependent. Maxim® XL caused a progressive lethal effect along the bioassays with higher toxicity on embryos than larvae, obtaining 50% lethal concentrations at 96, 336, and 504 h of 10.85, 2.89, and 1.71 mg/L for embryos, and 43.94, 11.79, and 5.76 mg/L for larvae respectively. Lethal 504-h no observed effect concentration values for embryos and larvae were 1 and 2.5 mg/L respectively. A stage-dependent toxicity of Maxim® XL was also demonstrated within the embryo development, with early stages more sensitive than the later ones, and blastula as the most sensitive developmental stage. The risk quotients obtained for chronic risk assessment determined a potential threat for the survival and continuity of R. arenarum populations under these conditions. The results indicate that the levels of the fungicide reaching amphibian habitats could be risky for the early development of this amphibian species. This study also emphasizes the necessity to evaluate the chronic effects of fungicides in pesticide risk assessment.