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Chemical integrity plays a crucial role in maintaining the ecological integrity of aquatic ecosystems. Despite its significance, assessments of ecological integrity often prioritize biological evaluations, leading to infrequent and inadequate scrutiny of chemical integrity. Additionally, a comprehensive framework for separately assessing chemical integrity has not been established. To address this issue, we established a new index for evaluating chemical integrity, achieved through indicator screening, normalization, and weight assignment. Combined with the threshold indicator taxa analysis (TITAN) and Pearson correlation analysis, main evaluation indicators and their indicator species were identified and the corresponding response threshold was determined. These thresholds were then applied to improve the normalization method, with weights determined by indicator species proportions. This index was applied to evaluate the chemical integrity of the Huai River Basin, which is one of the largest basins in China. The results indicated that ammonia nitrogen (NH3-N), nitrate nitrogen (NO2-N), pH, and turbidity (Turb) were identified as the core parameters for evaluating chemical integrity. The conventional normalization method (max–min normalization) led to overestimation of the assessment results, whereas improved normalization method based on ecological threshold yielded better and more reasonable results. This study provided a reference for the selection of appropriate indicators and improvement of normalization method to better assess chemical integrity. And it would become a useful tool for monitoring and rehabilitating the chemical integrity in such basins.

Wildfire management agencies in Canada are at a tipping point. Presuppression and suppression costs are increasing but program budgets are not. Climate change impacts and increasing interface values-at-risk are challenging suppression effectiveness and resulting in more wildfire disasters. We conducted semi-structured interviews with these agencies to understand the strategies, policies, and preparedness procedures they currently use to manage wildfires. We summarize the results of this national agency assessment, and based on what we heard and our review of agency internal documents, discuss agency challenges and opportunities to be better prepared for a future with more wildfire. A double wildfire paradox exists requiring communities and critical values in wildfire-dependent ecosystems to be FireSmart, and wildfire management agencies to allow more wildfire on the landscape by implementing a risk-based appropriate response approach. We conclude with a proposed future path for wildfire management in Canada. To co-exist with wildfire, agencies in Canada must also strengthen and adjust their wildfire management capacity and capability. This necessitates stronger horizontal collaboration, enhanced resource sharing, investments to develop innovative decision support tools, and an increased focus on prevention and mitigation. Keywords: Emergency management, Disasters, Wildfire management, Presuppression, Suppression, Preparedness

Fe-Mn-Ce metal oxides (FeMC) were prepared by using a co-precipitation method for the removal of tetracycline (TC). The FeMC composite has a good adsorption performance, and the maximum adsorption capacity at 318 K is 307.692 mg/g. FeMC metal oxides maintain good stability, and the removal rate of TC still reaches 85.24% after 5 cycles. The structural characteristics and adsorption mechanism of FeMC adsorbent have been systematically studied. According to the study of adsorption kinetics and adsorption isotherms, the adsorption process conforms to the quasi-secondorder kinetic model. Langmuir isotherm model is more suitable than Freundlich isotherm model to describe the adsorption equilibrium data. The Fourier-transform infrared spectrum shows that the adsorption between FeMC and TC is realized by the stretching vibration of C-H and the stretching vibrations of C-O or C-O-C. [ABSTRACT FROM AUTHOR]

Fe-Co-Ni-S (FCNS) nanocomposite is prepared through a hydrothermal method as a new efficient adsorbent to remove organic dyes in wastewater. The morphology, elemental composition and crystalline structure of the adsorbents have been studied by scanning electron microscopy, energy-dispersive X-ray spectroscopy and X-ray diffraction. The influence of the dosage of adsorbent and the pH value on the adsorption performance, the reusability of the nanocomposite, and effects of different anions are studied, which show that the adsorption rate of FCNS towards Rhodamine B (RhB) is as high as 99.63%. The adsorption kinetics of RhB on FCNS is described to pseudo-second- order model. At 318 K, the saturated adsorption capacity is 581.4 mg/g, which is consistent with the Langmuir isotherm. The kinetic results indicate that the adsorption process involves three steps, among which chemical adsorption and intraparticle diffusion play important roles. In addition, through the thermodynamic fitting of the adsorption process, it indicates that the adsorption of RhB by FCNS is spontaneous and accompanied by endothermic reaction. The FCNS nanocomposites has good adsorption performance under pH values ranging from 3 to 11. The FCNS has good reusability and adsorption performance after being reused 5 times. The Fourier-transform infrared spectrum indicates that hydrogen bonding is one of the main factors for influencing the adsorption. Compared with monometallic or bimetallic sulfides, the composite presented here has better adsorption performance and higher adsorption capacity, which will inspire some other emerging trimetallic sulfide composites for various advanced applications. [ABSTRACT FROM AUTHOR]

In this study, FeMoCoS (FMCS) nanocomposites were designed and fabricated through a hydrothermal method as a new efficient adsorbent to remove organic dyes in wastewater. The morphology and microstructure of the adsorbent were characterized by using scanning electron microscopy, energy-dispersive X-ray spectroscopy, Brunauer-Emmett-Teller surface area and Fourier-transform infrared spectroscopy. The effects of adsorption isotherm, kinetics, initial concentration and pH value of Rhodamine B (RhB) solution on the experiment were also studied. The results show that FMCS has good adsorption capacity for RhB solution, and the maximum adsorption capacity is 280.89 mg/g calculated by using a Langmuir isotherm model. Column study was made to achieve bulk removal of the dye. Column adsorption capacity has been found to be greater than the batch adsorption capacity. Moreover, the maximum removal rate of RhB reaches 99.64% at pH = 7 and pHpzc = 9.57 according to zeta potential. The adsorption kinetics match the pseudo-second-order model, indicating that the adsorption process is dominated by chemisorption. After 5-cycles of consecutive adsorption, the adsorbent can still maintain a high adsorption capacity, indicating a good potential for RhB removal from wastewater. [ABSTRACT FROM AUTHOR]

In this paper, Ni-Mo-S (NMS) nanomaterial was prepared by a simple hydrothermal method and used as a new adsorbent to remove Congo red (CR) from azo dye wastewater. The crystal phase, morphology and microstructure of the samples were characterized by scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction, Brunauer-Emmett-Teller surface area and Fourier transform infrared spectroscopy. The adsorption isotherm, kinetics and thermodynamics, as well as the influence of different Ni-Mo molar ratios and pH values on the experiment were studied. The experimental results show that NMS (Ni-Mo molar ratio 1:2) has a good adsorption capacity for CR. According to the Langmuir isotherm model, the maximum adsorption capacity was 490.20 mg/g. The adsorption kinetics is in good agreement with the pseudo-second-order model, and the adsorption equilibrium can be reached within 30 min. Moreover, the maximum removal rate of CR reaches 93.07% at pH = 7 and pHpzc = 7.64 according to zeta potential. Finally, the mechanism of adsorption of CR by NMS (Ni-Mo molar ratio 1:2) was discussed. [ABSTRACT FROM AUTHOR]

In this paper, flower-shaped Na2Mg(CO3)2 nanoparticles were synthesized by a simple hydrothermal method for defluoridation in water. The effects of the initial concentration of fluoride, pH value, and coexisting ions on the removal of fluoride were investigated. Na2Mg(CO3)2 nanoparticles were characterized by using scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and energy disperse analysis of X-rays. The experimental results show that the adsorption isotherm is consistent with the Freundlich model at pH = 7 and 35°C. When the initial concentration is 200 mg/L, the maximum adsorption capacity calculated by the Langmuir model is up to 113.64 mg/g. The adsorption kinetics is consistent with the pseudo-second-order model, and the adsorption equilibrium can be achieved within 100 min. There is little effect on Na2Mg(CO3)2 nanoparticles in the wide range of pH values (3-10). The fluoride removal rate reaches up to 92.26% at pH = 7 for the initial fluoride concentration of 5 mg/L, along with the adsorbent dose of 1 g/L. Except for PO43-, SO42-, and HCO3-, other anions don't affect the fluoride adsorption. The experiment results also demonstrate that the prepared adsorbents can be reused for at least six times. Finally, the mechanism for fluoride adsorption by Na2Mg(CO3)2 nanoparticles is discussed. [ABSTRACT FROM AUTHOR]