Cotton crop is highly susceptible to attack by sucking pests. Being an important oilseed and feed crop, it is essential to monitor the pesticides and ensure health protection at consumer level. Therefore, a method was validated to estimate fipronil and flonicamid in various cotton samples and risk assessment was performed. Contamination of oil in the extracts from the various oil seeds and cake samples is a major problem as this oil contaminates the column and interferes with the detection of pesticides. The present manuscript for the first time describes successful analysis of the pesticides from various cotton samples including cotton oil, seed, and cake. Quick, easy, cheap, effective, rugged, and safe (QuEChERS)-based methods were validated for estimation of fipronil and flonicamid in cotton samples and in soil by LC-MS/MS. Recoveries were within the acceptable range of 70–120% with relative standard deviation ≤ 20% and HorRat values < 0.3–1.3. R² was > 0.99. Matrix effects of 150 and 13.5% were observed for fipronil and flonicamid, respectively, in cotton leaves. Limits of quantitation (LOQs) were in the range of 0.0004 to 0.004 mg kg⁻¹ for fipronil and flonicamid. Cotton samples collected from a field study at different locations were analyzed. Half-life ranged from 2.2 to 5.8 for fipronil and 4.6 to 7.0 days for flonicamid. A pre-harvest interval of 33 days is suggested. The risk assessment studies at maximum residue level values showed HQ < 1 at pre-harvest interval (PHI). The methods being short and easy can be extended to estimate more types of pesticides in different oilseeds. Following a PHI of 33 days, fipronil and flonicamid can be used on cotton at standard dose. As the levels of fipronil and flonicamid were below determination limit in all the soils, the environmental risk is negligible.

Phenylurea herbicide residuals in soil may continuously contaminate surface water and groundwater due to unregulated and improper use. Herein, we reported a stable and active oxidation system including heterogeneous Fe-based layered double hydroxide materials as persulfate (PS) activators. Under mild conditions, 1% LDH in weight and 70 mM PS can completely degrade 500 mg/kg isoproturon in soil within 10 h, during which less than 0.1 ppm heavy metal leaching was detected. This remarkable performance was consistent in a broad pH range (3~11) and was resistant to various inorganic anions (Cl⁻, Br⁻, NO₃⁻, HCO₃⁻) and humic acid. Mechanism studies from scavenging tests, EPR, and fluorescence spectra collectively proved that besides •OH and •SO₄⁻, singlet oxygen (¹O₂) and superoxide (•O₂⁻) were also generated and were accounted for the oxidative degradation. This unique mechanism of generating diverse radicals was clearly distinguished from classic Fe(II)/PS system, significantly reduced the influence of varying parameters in water and soil matrix, and was suggestive to chemical oxidation system in soil remediation to avoid scavenging effects by background electrolytes or other components in water/soil matrix. Graphical abstract ᅟ

Bioaccumulation of five heavy metals (Cd, Cu, Mn, Pb, and Zn) in six plant organs (panicle, leaf, stem, root, rhizome, and bud) of the emergent and perennial plant species, Miscanthus sacchariflorus, were investigated to estimate the plant’s potential for accumulating heavy metals in the wetlands of Dongting Lake. We found the highest Cd concentrations in the panicles and leaves; while the highest Cu and Mn were observed in the roots, the highest Pb in the panicles, and the highest Zn in the panicles and buds. In contrast, the lowest Cd concentrations were detected in the stem, roots, and buds; the lowest Cu concentrations in the leaves and stems; the lowest Mn concentrations in the panicles, rhizomes, and buds; the lowest Pb concentrations in the stems; and the lowest Zn concentrations in the leaves, stems, and rhizomes. Mean Cu concentration in the plant showed a positive regression coefficient with plot elevation, soil organic matter content, and soil Cu concentration, whereas it showed a negative regression coefficient with soil moisture and electrolyte leakage. Mean Mn concentration showed positive and negative regression coefficients with soil organic matter and soil moisture, respectively. Mean Pb concentration exhibited positive regression coefficient with plot elevation and soil total P concentration, and Zn concentration showed a positive regression coefficient with soil available P and total P concentrations. However, there was no significant regression coefficient between mean Cd concentration in the plant and the investigated environmental parameters. Stems and roots were the main organs involved in heavy metal accumulation from the environment. The mean quantities of heavy metals accumulated in the plant tissues were 2.2 mg Cd, 86.7 mg Cu, 290.3 mg Mn, 15.9 mg Pb, and 307 mg Zn per square meter. In the Dongting Lake wetlands, 0.7 × 10³ kg Cd, 22.9 × 10³ kg Cu, 77.5 × 10³ kg Mn, 3.1 × 10³ kg Pb, and 95.9 × 10³ kg Zn per year were accumulated by aboveground organs and removed from the lake through harvesting for paper manufacture.

This study examines the impact of energy consumption, financial development, globalization, economic growth, and urbanization on carbon dioxide emissions in the presence of Environmental Kuznets Curve (EKC) model for BRICS economies, by using a family of econometric techniques robust to heterogeneity and cross-sectional dependence. Results from LM test, CIPS and CADF unit root test, Westerlund Cointegration test, the Dynamic seemingly unrelated regression (DSUR), and Dumitrescu-Hurlin Granger causality test show that (i) the data is cross sectionally dependent and heterogeneous; (ii) carbon dioxide emissions, energy consumption, financial development, globalization, economic growth, square of GDP and urbanization have integration of order one; (iii) the examined variables are co-integrated; (iv) energy consumption and financial development contribute to the carbon dioxide emissions whereas globalization and urbanization have negative but insignificant relationship with carbon dioxide emissions; (v) supports the EKC hypothesis in BRICS economies; (vi) bidirectional causality exists among energy consumption, financial development, economic growth and square of GDP with carbon dioxide emissions whereas globalization and urbanization have unidirectional relationship with carbon dioxide emissions. Since these panel techniques account for heterogeneity and cross-sectional dependence in their estimation procedure, the empirical results are robust and reliable for policy recommendations. Furthermore, this study also uses time series tests (ADF, P-P, and FMOLS) to find the empirical results for each of the country and finds mixed results. Empirical findings directed towards some important policy implications.

The biotoxicity of industrial effluents has attracted much concern in the wastewater treatment process. This research performed the biological treatment of the wastewater generated from food waste fermentation by anaerobic/anaerobic/anoxic/aerobic-membrane bioreactor (A³-MBR) system aiming at the meet of discharge standards and elimination of ecological risks to aquatic environment. The results showed that the A³-MBR could effectively remove pollutants such as COD, TN, ammonia, and TP in the wastewater. The study of biotoxicity revealed that the acute toxicity was mainly contained in the polar and mid-polar fractions of the wastewater, and the remained acute toxicity was less than 0.6 TU, much lower than the secondary effluent of domestic wastewater treatment plant. The genotoxicity was found abundantly in the polar fractions and less in mid-polar fractions, and a relatively low genotoxicity (0.086 μg 4-NQO/L) was obtained in the final effluent of the treatment system. The fulvic acid-like compounds and humic acid-like compounds were the main cause of the acute toxicity, while the aromatic proteins and soluble microbial by-products mainly resulted in the genotoxicity in the wastewater.

Arbuscular mycorrhizal (AM) fungi play an important role in plant tolerance of heavy metal contamination. In this study, a pot experiment was conducted to illustrate the effects of the two AM fungi species Funneliformis mosseae (Fm) and Rhizophagus irregularis (Ri) on plant growth of Oryza sativa L. either with or without ethylenediamine tetraacetate (EDTA) addition and during exposure to five Cd concentrations (in the range of 0–5 mg kg⁻¹). The results showed that Fm inoculation achieved greater mycorrhizal colonization and mycorrhizal dependency indexes than Ri inoculation. In addition, the effects of AM fungi on Cd biosorption and translocation in rice were also investigated in the presence of EDTA. Despite cooperative adsorption, the Freundlich isotherm could describe the biosorption effects of Cd on rice roots regardless of AM fungi inoculation or EDTA addition. Cd concentrations in mycorrhizal roots increased but decreased in mycorrhizal shoots in contrast to the control treatment. Although EDTA addition negatively inhibited the uptake of Cd to mycorrhizal shoots, lower translocation factor (TF) and bioconcentration factor (BCF) were still observed in treatments with EDTA compared to control treatment. Our findings suggest that Ri and Fm inoculation enhanced Cd immobilization in the roots, thus preventing Cd entry into the food chain during exposure to low and high Cd stress, respectively.

Dissolved organic phosphorus (DOP) in rainwater runoff or other contaminated waters can cause or aggravate eutrophication of water bodies. Water treatment residual (WTR) containing spent coagulant has been shown to provide excellent adsorption capacity for inorganic phosphorus such as orthophosphate, but little information has been available on adsorption of DOPs by WTR. In this study, the adsorption characteristics of myo-inositol-1,2,3,4,5,6-hexakisphosphate (IHP), a prototype DOP in soil and stormwater, by WTR were investigated through batch adsorption equilibrium and kinetic experiments. The influences of pH and various size fractions of WTR on the adsorption capacity were tested and analyzed, and the adsorption mechanism was elucidated based on Fourier-transform infrared spectroscopy (FTIR) analysis. The experimental results showed that WTR can effectively adsorb IHP from simulated rainwater, and the IHP uptake was favored under neutral and acidic conditions. Moreover, the 1.0–2.0-mm fraction of the WTR particles was most suitable for practical application because of the well-balanced adsorption rate and capacity. The classical Langmuir isotherm model well described the equilibrium adsorption data and the pseudo-second-order kinetic model adequately interpreted the rate data. Thermodynamic analysis revealed that the adsorption is a spontaneous, endothermic, and entropy-driven reaction. The FTIR analysis indicated that adsorption of IHP on WTR is associated with the formation of ≡Al–PO₃⁻ groups and the release of –OH from WTR. A comparison of the adsorption capacities of orthophosphate and IHP on WTR suggested that binding one IHP may take two times more sites than for orthophosphate, indicating that two of the six phosphate groups in IHP were bound to WTR. This work shows that recycled WTR may be used as a low-cost adsorbent for effective removal of organic phosphate in gray water and wastewater.

Owing to the similar mechanisms of antibiotic and metal resistance, there is a growing concern that metal contamination may select for antibiotic resistance genes (ARGs) in the environment. Here, we constructed short-term laboratory microcosms to investigate the dynamics of a wide range of ARGs and two copper (Cu) resistance genes in an agricultural soil amended with a gradient of Cu concentrations (0~1000 mg kg⁻¹). Mobile genetic elements (MGEs) were also quantified as a proxy for the horizontal gene transfer potential of ARGs. We detected 126 unique ARGs across all the soil samples using the high-capacity quantitative PCR array, and multidrug and β-lactam resistance were the most abundant ARG categories. The copper amendments significantly enhanced the absolute and relative abundances of ARGs and MGEs, which gradually increased along the gradient of increasing Cu concentrations. The two Cu resistance genes (copA and pcoR) were highly enriched in low-level Cu treatment (50 and 100 mg kg⁻¹), and their abundances decreased with the increasing Cu concentrations. The level of metal and antibiotic resistance gradually declined over time in all Cu-amended treatments but was still considerably higher in contaminated soils than untreated soils after 56 days’ incubation. Significant associations among ARGs and MGEs were revealed by the network analysis, suggesting the mobility potential of antibiotic resistance in Cu-amended soils. No significant positive correlations were found between ARGs and copper resistance genes, suggesting that these genes are not located in the same bacterial hosts. Taken together, our results provide empirical evidence that short-term copper stress can cause evolution of high-level antibiotic and metal resistance and significantly change the diversity, abundance, and horizontal transfer potential of soil ARGs.

Highly microporous carbons were prepared from argan nut shell (ANS) using steam activation method. The carbons prepared (ANS@H2O-30, ANS@H2O-90, and ANS@H2O-120) were characterized using X-ray diffraction, scanning electron microscopy, Fourier-transform infrared, nitrogen adsorption, total X-ray fluorescence, and temperature-programmed desorption (TPD). The ANS@H2O-120 was found to have a high surface area of 2853 m²/g. The adsorption of bisphenol A and diuron on ANS@H2O-120 was investigated. The isotherm data were fitted using Langmuir and Freundlich models. Langmuir isotherm model presented the best fit to the experimental data suggesting micropore filling of ANS@H2O-120. The ANS@H2O-120 adsorbent demonstrated high monolayer adsorption capacity of 1408 and 1087 mg/g for bisphenol A and diuron, respectively. The efficiency of the adsorption was linked to the porous structure and to the availability of the surface adsorption sites on ANS@H2O-120. Response surface method was used to optimize the removal efficiency of bisphenol A and diuron on ANS@H2O-120 from aqueous solution. Graphical abstract ᅟ

Prediction of the development and evolution process of coal spontaneous combustion is of great significance to its prevention and control. Through the testing of different metamorphic degrees coal programmed heating characteristics and the infrared functional groups, the critical temperatures of the coalification process were analyzed and a method to predict the period of spontaneous combustion was established according to the characteristic of the critical temperature change. What can be inferred from this research is that the critical temperature of activation energy of coal in programmed heating experiments can characterize the nature of coal at low temperature and the macrocritical temperature point can be obtained from the characteristics of the activation energy change during the low-temperature period. The critical point of coal functional groups in terms of its micro changes is similar to its macro changes, the absorption intensity of the characteristic peak shows a general increasing trend, with an initial decline and then increase, followed by a decrease and a subsequent increase. In the high-temperature combustion process, the activation energy is not constant and changes from a negative value to 0, then the activation energy changes to a positive value, and finally goes down to a negative value. Therefore, the prediction of development period of spontaneous combustion can be achieved through the critical temperature of activation energy which acts as the critical temperature in high-temperature combustion process, and the prediction of low-temperature oxidation process is based on the critical temperature of activation energy in programmed heating process and the macro critical temperature of absorption intensity of coal functional groups.