Three new anticoagulant rodenticides R₁, R₂, and R₃ were designed. The containing fluorine acute toxicity groups was added to 1,3-indandione derivative. Analysis method of synthesized anticoagulant rodenticides were IR, ¹H NMR. Acute bioactivity of the new rodenticides was evaluated, including the coefficient of absorb food and median lethal dose (LD₅₀). Average coefficient of absorbed food for R₁ was 0.54 and LD₅₀ of R₁ was 2.15 mg/kg. Average coefficient of absorbed food for R₂ was 0.59 and the acute oral LD₅₀ of R₂ was 2.65 mg/kg. Average feeding coefficient of R₃ was 0.68 and the acute oral LD₅₀ of R₃ was 3.12 mg/kg. Experiments showed that rat’s death peak was at about 72 h and rodenticides had good characteristics of acute medicine. The LD₅₀ of three new fluoride anticoagulant rodenticides showed that they had good palatability for big white rats, and they had a strong poison effect on rodent. The result of all experiments proved that the synthesis of 1,3-indan diketone used as parent compound of new anticoagulant rodenticides could replace the current 4-hydroxyl coumarin as parent compound of the second-generation anticoagulant rodenticides. 1,3-Indan diketone would be widely used as parent compound of anticoagulant rodenticides.

Industrial hydrodesulfurization method has not been efficient for removal of dibenzothiophene (DBT) from petroleum distillates. Therefore, in this current study, adsorptive desulfurization (investigated in batch mode) was carried out using functionalized carbon nanotubes (FCNTs) to reduce the amount of DBT in a model diesel. Different techniques, such as, scanning electron microscope (SEM) equipped with energy-dispersive X-ray (EDX), were used to check the morphological structure and the elemental compositions of the adsorbent; Fourier transmission infrared (FTIR) was used to check the chemical functionalities of the adsorbent; and nitrogen physisorption at 77 K was used to check the surface area, pore size, and pore volume of the adsorbent. The results show that the FCNTs outperformed the non-functionalized carbon nanotubes (CNTs) during the desulfurization by about 10%, indicating the functionalization did improve the desulfurization performance of the CNTs. The % removal of DBT by the FCNTs and CNTs was 70.48 and 60.88%, respectively. It can be concluded that the acid treatment of CNTs enhanced its surface affinity for DBT, thus contributing to the improved adsorption performance of the adsorbent. The isotherm results show that Freundlich isotherm model described well the mechanism of the adsorption process for both CNTs and FCNTs. In addition, pseudo second-order kinetics describes the behavior of the adsorbents during the adsorption process. The results obtained in this study therefore show that functionalized CNTs could be efficient and potential adsorbent for removal of DBT in petroleum distillate (e.g., diesel), to meet up with the stringent policies regarding emission of sulfur oxides.

Intertidal macroalgae suffer different environmental conditions and mat densities during growing period. In the present study, Ulva lactuca Linnaeus were collected from high, intermediate, and low tidal zones at Nan’ao Island, China. These algal photosynthetic pigments and photosynthesis behaviors with different mat densities were measured. The aim is to examine how the physiological responses and acclimation match the representative tidal distribution and algal mat density. The photosynthetic pigment (chlorophyll a and carotenoid) contents and irradiance-saturated maximum photosynthetic rates (Pₘₐₓ) were greater in low zone–grown U. lactuca compared with the algae grown at high and intermediate zones. Under low algal mat density, the Pₘₐₓ, apparent photosynthetic efficiency (α), and dark respiration rate (Rd) of U. lactuca grown at low zone were increased, whereas the irradiance saturation points (Iₖ) were decreased, compared with the algae grown at higher zone. However, the Pₘₐₓ of high and intermediate zone–grown U. lactuca at high algal mat density were greater than at low density. Moreover, the pH compensation point of low zone–grown thalli (9.98) was lower than the higher zone–grown thalli (more than 10.15); however, the chlorophyll fluorescence parameters (reflect photosynthetic system activity) of the thalli collected from the three different zones were similar. Therefore, we proposed that the effects of varied densities on the photosynthetic rates of these three tidal zone–grown U. lactuca thalli were different, which might be related with different capacity of HCO₃⁻ utilization of macroalgae at their zonations.

In this study, aqueous extracts of Musa paradisica (banana) peels and Dolichos lablab (Indian beans) seeds were prepared and tested as natural coagulants for turbidity removal from simulated turbid water. Effects of extraction time (15, 30, and 45 min), dosage (0.2 to 1.0 mL/L), and water pH on turbidity removals by the natural coagulants were evaluated. In both cases, the extraction time of 45 min for the preparation of aqueous extract and dosage of 0.6 mL/L gave the best results in terms of turbidity removal. Natural coagulants from M. paradisica peels powder could efficiently remove turbidity (> 83%) at all tested pH values (3.0 to 12.0) with maximum turbidity removal of 98.14% at pH 11. In the case of D. lablab seeds, low turbidity removal (71–74%) was observed at pH between 5.0 and 9.0. The maximum turbidity removal (98.84%) was obtained at pH 11. The scanning electron microscopy (SEM) analysis of the settled flocs revealed that more compact flocs formed using M. paradisica peels extract than those developed using D. lablab seeds extract. The chemical analysis and Fourier transform infrared (FTIR) spectroscopy of the extracts revealed that polymeric substances (carbohydrate and proteins) having functional groups –OH, C–N, C–C, –COOH, and N–H might be responsible for the coagulation activity. The zeta potential measurements of natural coagulants revealed that the possible coagulation mechanism would be adsorption and bridging between particles. This study demonstrated the potential use of aqueous extracts of M. paradisica peels and D. lablab seeds as low-cost natural coagulants for turbidity removal.

The adaptability of ISO 14001 is considered as one of the most useful tools for environmental sustainability and worldwide competitive advantage; however, the future of ISO 14001 certification faces some uncertainties because of its uneven acceptance in various countries. These uncertainties, if not properly managed, can hinder the implementation of business management systems in these countries. In order to guide policymakers in better management of ISO 14001 in future with certainty, this study aims to forecast the ISO 14001 certifications for 10 years for China, India, the USA, Italy, Japan, and Germany, the top six certified countries, through advanced mathematical modeling, namely grey models, even GM (1,1), discrete GM (1,1), and non-homogenous discrete grey model (NDGM). The benefits of mentioned models are ensured accuracy in assessment using small samples and poor information. Moreover, current research is a pioneer in the certifications growth analysis using the Synthetic Relative Growth Rate and Synthetic Doubling Time models. Finally, the empirical analysis indicated that China is constantly leading in terms of its ISO 14001 certifications till 2026 and the performance of developing countries was spectacular. Furthermore, the article has proposed some suggestions for the policymakers to make the environment more sustainable.

In this work, particles of nanoclay modified with poly(diallyldimethylammonium), PDDA, namely PDDA/PGV, were obtained and characterized by infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), X-ray diffraction (XRD), surface area measurement (BET surface area), measurement of zero charge point (pHPCZ), and scanning electron microscopy with energy-dispersive spectroscopy (SEM/EDS). The PDDA/PGV particles were applied as adsorbent for the removal of gallic acid (GA) from aqueous solution. The effect of various parameters, such as solution pH, contact time, adsorbent mass, and temperature, was studied. The maximum adsorption capacity of PDDA/PGV (238.45 mg g⁻¹) was observed at pH 4 and 15 °C. The study of adsorption kinetics and isotherms revealed that the adsorption process was better fitted by pseudo-first order and Freundlich model, respectively. The obtained thermodynamic parameters indicate that the adsorption of GA is spontaneous and enthalpy-driven.

The increase in biodiesel production has been leading to an excess amount of crude glycerol and, consequently, serious environmental issues. For this reason, electrospun chitosan-based nanofibers (CB-EN), composed by chitosan and poly(ethylene oxide) (PEO), were synthesized to apply in the biosorption of impurities from industrial glycerol. To evaluate the biosorption efficiency, the chitosan-based nanofiber was compared to other chitosan-based biosorbents (chitosan biopolymeric film and chitosan powder). The equilibrium and thermodynamic studies were successfully performed to comprehend the interaction mechanisms through the biosorption of glycerol pigments onto electrospun chitosan-based nanofibers. The temperature effect was evaluated by experimental equilibrium curves. Freundlich and BET models were used to estimate isotherm parameters. Gibbs free energy change, enthalpy change, entropy change, and isosteric heat of biosorption were quantified. The equilibrium curves showed that the highest equilibrium relative adsorption (340.7 g⁻¹) was reached at 60 °C. The BET model was the most suitable to represent the equilibrium behavior. The thermodynamic parameters indicated that the biosorption was spontaneous, exothermic, random, and energetic heterogeneous. Therefore, this work developed a green and efficient alternative to refine industrial glycerol. Graphical abstract Note: This data is mandatory. Please provide

In this study, two novel low water-soluble sericin and alginate-based biosorbents were successfully developed for precious metal removal from wastewater: sericin and alginate particles chemically crosslinked by proantocyanidins (SAPAs) and sericin, alginate and polyvinyl alcohol particles (SAPVA). The proportions of proantocynidins (PAs) or polyvinyl alcohol (PVA) added to sericin (2.5% w/v) and alginate (2.0% w/v) blend were 0.5, 1.5, 2.5 and 3.5% w/v. Among these concentrations, particles produced with 0.5% w/v of PVA or 2.5% w/v of PAs presented the lowest water solubility percentages (3.74 ± 0.05 and 3.56 ± 0.21%, respectively) and the following metallic affinity order: AuCl₄⁻ > PdCl₄²⁻ > PtCl₆²⁻ > Ag⁺. Then, gold biosorption kinetics by SAPAs was evaluated at three gold initial concentrations (72.88, 187.12, and 273.79 mg/L), and its performance was compared to activated carbon adsorbent uptake. The data modeling revealed that the process follows pseudo-first-order kinetics and is mainly controlled by external diffusion. SAPAs before and after gold biosorption (SAPAs-gold) were characterized by scanning electron microscopy coupled with energy dispersive X-ray spectroscopy, optical microscopy, helium pycnometry, mercury porosimetry, N₂ physisorption, and Fourier-transform infrared spectroscopy.

Gainful utilization of stems of the pernicious weed, Ipomoea carnea, to prepare good quality carbon and its modification with aluminum oxyhydroxide (AlOOH) nanoparticles for efficient defluoridation from contaminated drinking water is discussed in this paper. Surface functional groups are enhanced by functionalization of the carbons under acid treatment which acted as anchor to the AlOOH nanoparticles. Formation of AlOOH particles over the carbon surface is confirmed from X-ray diffractometry analysis. The AlOOH–carbon nanocomposite showed higher fluoride removal capacity than the neat AlOOH nanoparticles with a maximum removal capacity in the range of 46.55–53.71 mg g⁻¹. Reaction kinetics and isotherm studies showed that fluoride adsorption is quite feasible on the adsorbent surface. The column study showed the possibility of the adsorbent for large-scale applications. The adsorbent can be regenerated by a mild treatment with 0.1 N NaOH solutions. The adsorbent is highly capable for defluoridation from synthetic as well as fluoride-contaminated natural water and, thus, can be used as an alternative for commercial defluoridation adsorbents. The use of Ipomoea carnea for defluoridation can be a way of producing low-cost adsorbent material, and the use for such purposes may also be helpful to control the weed up to a good extent.

The occurrence, seasonal variation and emission of nine widely used phosphorus flame retardants (PFRs) were investigated in a wastewater treatment plant (WWTP) located in Guangzhou, China, over 1 year. Results showed that PFRs were widely detected in wastewater and sewage sludge. Tris(2-chloroisopropyl) phosphate (TCIPP) was the most dominant PFRs in influent, effluent, and sludge. Significant seasonal variation of total PFRs in the influent was observed (p < 0.05). However, no significant seasonal variation found in chlorinated and alkyl PFRs. The emission of PFRs was comparable with the previously reported values of decabromodiphenyl ether in WWTPs. Risk quotient for PFRs showed low eco-toxicity risk in effluent for aquatic organisms. Since the removal efficiency of total PFRs was less than 30% and the use of PFRs had been increasing, continuous monitoring of the environmental impact on the receiving water is still needed.