Ecological Safety Research Articles

Highly-efficient peroxymonosulfate activation by porous nano-MgO for tetracycline degradation: Surface hydroxyl groups and oxygen vacancies synergetic mediated nonradical process

Heterogeneous transition metal activation of peroxymonosulfate (PMS)-based advanced oxidation processes is limited by low cycling efficiency, secondary contamination, and high toxicity. In this study, a non-transition metal porous nano-MgO catalyst from natural dolomite was synthesized and PMS activation was performed to degrade tetracycline (TC). The nano-MgO/PMS system could achieve TC degradation of 88.09 % within 20 min under the optimum parameters (nano-MgO dosage of 0.2 g·L−1, PMS concentration of 0.3 mM), exceeding the efficiency of the PMS-alone system (11.66 %) by 7-fold, which was related to large specific surface area (41.19 m2·g−1) and defect structure of porous nano-MgO catalysts. As revealed by the quenching tests and electron paramagnetic resonance (EPR) analysis, different from transition metal activation PMS where radicals are generated, singlet oxygen (1O2) was essential in the nano-MgO/PMS oxidation process. Notably, the density functional theory (DFT) calculations demonstrated that nano-MgO with surface hydroxyl groups and oxygen vacancies exhibited the longer O-O bond length (1.47 Å), stronger adsorption energy of PMS (-4.07 eV), and faster electron transfer (0.91 e) than the only nano-MgO with surface hydroxyl groups, proving the surface hydroxyl groups and oxygen vacancies active sites in nano-MgO could synergistically mediate the PMS activation process. Furthermore, the proposed three TC degradation pathways and the toxicity evaluation of intermediates suggested that nano-MgO/PMS system have good ecological safety. This work offers an innovative approach for the cost-effective preparation of porous magnesium oxide with highly efficiency, offering a new perspective for understanding the PMS activation mechanism induced by non-transition metal.

Effects and mechanisms of kitchen waste organic fertilizers application on soil nitrogen transformation, plant pathogenic virulence genes, and metabolites

The application of organic fertilizers enhances soil fertility and alters the function and structure of the soil microbial communities. When subjected to aerobic composting, kitchen waste is transformed into organic fertilizer. However, the ecological benefits and safety risks of kitchen waste organic fertilizers (OF) in soil require further evaluation. Therefore, this study conducted a pot experiment to investigate the effects and mechanisms of OF application on soil properties, crop growth, nitrogen transformation, plant pathogenic virulence genes, and metabolites. The results indicated that OF treatment promoted vitamin C synthesis in pakchoi (35.23–48.00 %) and reduced soil N2O emissions during cultivation compared with inorganic fertilizer (IF) (65.50–68.08 %) (P<0.01). IF treatment significantly increased the abundance of Rhodanobacter (6.41 %) and Nitrobacter (3.16 %), leading to increased N2O emissions (17.94 mg kg−1). Key nitrogen metabolism enzymes and functional genes indicated that nitrification and denitrification pathways were the primary contributors to N2O production. Metagenomic results revealed that IF treatment enhanced virulence gene pathogenicity through quorum sensing (QS), whereas OF treatment reduced virulence gene accumulation in plant pathogenic bacteria. Metabolomic analysis demonstrated that OF treatment significantly upregulated substances beneficial to soil activity and plant growth, while inhibiting pollutant expression. PLS-PM results indicated that soil properties played a pivotal role in shaping the intricate relationships among microbial communities, functional genes, and substance metabolism. This study demonstrated that OF application contributed to the promotion of plant health and optimization of soil ecosystems, thereby providing theoretical support for the further expansion of OF applications in agriculture.

Public Willingness to Pay for Farmland Eco-Compensation and Allocation to Farmers: An Empirical Study from Northeast China

Farmland eco-compensation, as a typical payment for ecosystem services scheme, aims to address trade-offs between environmental and developmental objectives. As indispensable eco-compensation supporters, the public’s willingness to pay (WTP) for farmland eco-compensation and the allocation to farmers directly affect ecological safety and sustainable development for farmland. Therefore, this study links the public’s WTP for the farmland eco-compensation to the financial subsidies received by farmers and presents a theoretical framework and research approach that connects stakeholders, applying improved choice experiments for empirical study in the black soil region of northeastern China. The results showed that the public has a positive WTP for the farmland eco-compensation program that improves the area, soil thickness, and organic content expeditiously. The public’s WTP allocation for eco-compensation varies considerably, with the share allocated to farmers in their WTP averaging 46.96%, showing a benchmark for compensation standards. The results revealed the influential relationship between the socioeconomic characteristics of the public with WTP allocation and the preferences for farmland eco-compensation, such as the positive correlation between age with WTP allocation and females’ greater preference for eco-compensation. These findings can provide new perspectives and approaches to exploring sustainable pathways for farmland eco-compensation.

Differences in the environmental awareness of the Polish population

Motives: A fundamental tenet of sustainable development (SD) posits that all human endeavors should prioritize ecological safety. This underscores the significance of the knowledge about the ways in which these activities manifest in social attitudes, as an indicator of environmental awareness (EA) levels. Given the relevance of environmental EA, this issue should be examined across diverse communities and social groups, such as urban and rural residents, to catalyze the adoption of SD principles. It is assumed that the concentration of the population and societal structures in urban centers stimulate the development of concepts and solutions that subsequently disseminate to rural areas through urbanization and modernization patterns. Consequently, the potential disparities in EA and pro-environmental behaviors should be analyzed based on community members’ place of residence and economic status. Aim: The objective of this study was to assess differences in EA levels within the Polish population in the context of SD principles, based on demographic and social characteristics, as well as the respondents’ place of residence. Results: The study revealed several connections between attitudes toward sustainability and pro- -environmental activities. The identified attitudes were associated with demographic, economic, and spatial factors. The results indicate that EA levels are relatively high among Polish residents, irrespective of spatial distribution. Furthermore, significantly higher levels of EA-related activities were noted among urban dwellers, particularly the young and well-educated. Interestingly, a similar trend was noted among the residents of suburban zones. In contrast, rural inhabitants exhibited lower levels of EA compared to their urban counterparts.

BiVO4-Driven photocatalytic degradation of pharmaceutical in Slurry Bubble Column Reactor: Influencing factors and toxicological profiling

As the pursuit for sustainable and effective solutions to address environmental pollution intensifies, a comprehensive approach in photocatalysis has become a subject of increasing interest. In this study, BiVO4 photocatalyst synthesized through a pH-controlled hydrothermal method was used for the degradation of tetracycline (TET), a prevalent pharmaceutical pollutant. Optimal conditions, particularly a pH of 9 and enriched dissolved oxygen (DO), significantly improve TET removal, achieving a 96 % degradation efficiency with a rate constant of k = 0.1069 min−1. The investigation revealed that the degradation predominantly involves the generation of reactive oxygen species (ROS), notably O2•−, which play a crucial role in the degradation of TET. Using the “ecological structure–activity relationships” (ECOSAR) program, the toxicity of the intermediates was assessed, highlighting the environmental implications of the photocatalytic process. In addressing the scalability for industrial applications, a Slurry Bubble Column Reactor (SBCR) was employed, and separation-stability tests of the photocatalyst were conducted. These tests confirmed the photocatalyst’s long-term effectiveness and stability, underscoring its potential for repeated use in large-scale applications. This comprehensive research not only underscores the potential of BiVO4 in removing environmental contaminants but also provides vital insights into ecological safety.

China's nuclear power in the context of decarbonization of the global energy industry

The global structure of energy resource consumption is analyzed. It is shown that the total consumption of energy resources in the 20th century increased almost 15 times and amounted to about 118 PWh in 2000. Of these, more than 80% were fossil (natural) energy carriers, 13 % were renewable energy sources and more than 6 % were nuclear power. This trend has continued for many years. Renewable energy sources and nuclear power are projected to dominate the growth of global energy consumption, meeting on average more than 90 % of the additional demand. China ranks first in the world in terms of GDP and the rate of development of the electric power complex, as well as in terms of production volume and the rate of development of nuclear power. The structure of electricity generation by fuel type in countries (TOP 5, 2021) with high energy consumption has been analyzed. It is shown that the main players in this market are three countries: China (30 %), USA (13 %) and India (6 %). The volume of electricity production in China is almost three times larger than in the EU countries and almost 7 times larger than in Russia. The structure of nuclear energy and China's achievements in this field are considered. It is shown that in the context of nuclear technologies (creation of fourth-generation reactors, development of technologies close to the full closed cycle of nuclear waste processing) China is already ready to significantly expand the scope of nuclear energy. Special attention is paid to the safety of nuclear facilities operations. The main problem China will face is the absence of an insurmountable barrier between civilian and military use of such technologies. This poses a serious threat to the ecology and life safety of the country. In the long term, nuclear power must also solve the problem of safe, long-term disposal of radioactive waste. It is shown that in the future China needs to re-examine its nuclear program in the context of cooperation with International Nuclear Security Organizations.

Occurrence, accumulation, ecological risk, and source identification of potentially toxic elements in multimedia in a subtropical bay, Southeast China

Potentially toxic elements (PTEs) in seawater and sediments may be amplified along the aquatic food chain, posing a health threat to humans. This study comprehensively analyzed the concentrations, distribution, potential sources, and health risk of 7 PTEs in multimedia (seawater, sediment and organism) in typical subtropical bays in southern China. The results indicated that Zn was the most abundant element in seawater, and the average concentration of Cd in sediment was 3.93 times higher than the background value. Except for As, the seasonal differences in surface seawater were not significant. The content of Zn in fishes, crustacea, and shellfish was the highest, while the contents of Hg and Cd were relatively low. Bioaccumulation factor indicated that Zn was a strongly bioaccumulated element in seawater, while Cd was more highly enriched by aquatic organisms in sediment. According to principal component analysis (PCA), and positive matrix factorization (PMF), the main sources of PTEs in Quanzhou Bay were of natural derivation, industrial sewage discharge, and agricultural inputs, each contributing 40.4 %, 24.2 %, and 35.4 %, respectively. This study provides fundamental and significant information for the prevention of PTEs contamination in subtropical bays, the promotion of ecological safety, and the assessment of human health risk from PTEs in seafood.

Scalable Cathodic H2O2 Electrosynthesis using Cobalt-Coordinated Nanocellulose Electrocatalyst.

Converting hierarchical biomass structure into cutting-edge architecture of electrocatalysts can effectively relieve the extreme dependency of nonrenewable fossil-fuel-resources typically suffering from low cost-effectiveness, scarce supplies, and adverse environmental impacts. A cost-effective cobalt-coordinated nanocellulose (CNF) strategy is reported for realizing a high-performance 2e-ORR electrocatalysts through molecular engineering of hybrid ZIFs-CNF architecture. By a coordination and pyrolysis process, it generates substantial oxygen-capturing active sites within the typically oxygen-insulating cellulose, promoting O2 mass and electron transfer efficiency along the nanostructured Co3O4 anchored with CNF-based biochar. The Co-CNF electrocatalyst exhibits an exceptional H2O2 electrosynthesis efficiency of ≈510.58mgL-1cm-2h-1 with an exceptional superiority over the existing biochar-, or fossil-fuel-derived electrocatalysts. The combination of the electrocatalysts with stainless steel mesh serving as a dual cathode can strongly decompose regular organic pollutants (up to 99.43% removal efficiency by 30min), showing to be a desirable approach for clean environmental remediation with sustainability, ecological safety, and high-performance.

Adsorption behaviors of perfluorooctanoic acid on aged microplastics.

The presence of perfluoroalkyl substances (PFAS) in the environment poses a significant threat to ecological safety and environmental health. Widespread microplastics (MPs) have been recognized as vectors for emerging contaminants due to human activities. However, the adsorption behaviors of PFAS on MPs, especially on aged MPs, have not been extensively investigated. This study aimed to investigate the adsorption behaviors of perfluorooctanoic acid (PFOA) on aged MPs (polystyrene, polyethylene, and polyethylene terephthalate) treated with UV irradiation and persulfate oxidation under salinity and dissolve organic matter (DOM) condition. Carbonyl index values of MPs increased after the aged treatment, indicating the production of oxygen-containing groups. The PFOA adsorption on aged MPs was impacted by the co-existence of Na+ ions and DOM. As PFOA adsorption onto aged MPs was mainly controlled by hydrophobic interaction, the electrostatic interaction also made a contribution, but there was no significant change in PFOA adsorption behavior between the pristine and aged MPs. While these findings provide insight into PFAS adsorption on aged MPs, further research is necessary to account for the complexity of the real environment. PRACTITIONER POINTS: Adsorption behaviors of perfluorooctanoic acid (PFOA) on aged microplastics were investigated. Hydrophobic interaction mainly controlled PFOA adsorption on aged microplastics (MPs). Co-existence dissolve organic matter and salinity influenced PFOA adsorption behaviors on aged MPs.

Two-step recovery of Pb(II) and Cd(II) with thiophene functionalized hydrogel from lead-acid battery wastewater: Insight into pH-regulated separation

Lead-acid batteries (LAB) are one of the most harmful batteries to the environment and human health. LAB wastewater contains Pb(II) and Cd(II), meanwhile, strongly acidic media (pH ≤ 3.0) poses a serious threat to ecological safety and human health. Herein, a novel thiophene functionalized biomass-based hydrogel (PEITC-SA) containing various groups was prepared by a two-step synthesis strategy involving liquid-phase modification and dopant-induced crosslinking. The static experiments relating to selectivity, kinetics and equilibria confirmed that PEITC-SA not only had a high adsorption capacity and selectivity for Pb(II) at pH 2.0, but also had a good adaptability for both Pb(II) and Cd(II) at pH 3.0. Moreover, the coexistence of inorganic salts and organic compounds had little effect on the adsorption of Pb(II) and Cd(II). Complexation was confirmed as the main adsorption force at pH 2.0, meanwhile at pH 3.0, electrostatic interaction, ion exchange interaction and complexation were all involved. According to Density Functional Theory calculations, tetradentate coordination of thiophene and amino groups was the most stable. Dynamic column experiments towards simulated LAB wastewater demonstrated the high efficiency and feasibility of pH-regulated fractional treatment, which of unexpected economic prospects. Furthermore, PEITC-SA could be easily desorbed with dilute HCl solution. Therefore, PEITC-SA possessed satisfactory potential for the resource recovery towards LAB wastewater through pH-regulated two-step separation.

Ecological Safety and Regional Cooperation in the Asia-Pacific

On August 24, 2023, the discharge of nuclear-contaminated water from Fukushima into the ocean, an action that has sparked widespread concern and apprehension within the international community, particularly among nations in the Asia-Pacific region. This issue transcends mere environmental concerns, touching upon transnational cooperation and regional policy coordination. The strategic significance of the Asia-Pacific region in international studies is underscored by the concentration of multiple national powers engaging in complex strategic games to achieve their respective national interests and objectives. This paper aims to outline the context of nuclear wastewater discharge, analyze the potential environmental risks, and explore the threats to the marine ecological safety of neighboring countries. It discusses how this decision has become both a challenge and an opportunity for cooperation among Asia-Pacific nations in terms of environmental protection and marine ecological safety. Additionally, the paper employs the Graph Model for Conflict Resolution (GMCR) method, based on existing multilateral cooperation frameworks such as regional marine cooperation organizations and international legal norms, to study the challenges and opportunities for regional cooperation in the context of nuclear wastewater discharge. This research may offer insights and guidance for mitigating current threats to marine ecological safety in the Asia-Pacific, and for constructing a more sustainable and resilient regional marine governance structure.

ECOLOGIZATION OF TOURISM AS A COMPONENT OF THE CONCEPT OF SUSTAINABLE DEVELOPMENT

Topicality. The ecologization of production processes and the transfer of the entire system of economic reproduction of humanity to the principles that meet the objectives of environmental protection are an important condition for sustainable development. The strategy of sustainable development is one of the key and priority in all branches of industry, national economy and economics. Its principles and main provisions are aimed at achieving harmony between the growth of economic indicators, stability in the social sphere and environmental protection. Preservation of natural resources, maintenance of their sustainability and the transition to resource-saving, energy-efficient technologies is almost one of the key tasks on the agenda Aim and tasks. The purpose of the work is the analysis of the basic theoretical provisions of the concept of "ecologization of tourism" and the development of its directions. Materials and Methods. Calculation and compliance with the norm of permissible tourist load on the territory involves the normalization of loads based on quantitative indicators as one of the methods of ecologically-oriented management of the development of tourist activity. Reserch results. Within the framework of the conducted research, we consider it expedient to single out the main directions of ecologization of the tourism sphere at two levels: the first - measures directly related to the implementation of ecological principles in the tourism sphere; the second level does not directly concern the tourism industry, but in general promotes the implementation of the ecological trend in the development of the tourism industry. Conclusion. It is worth noting that the implementation of the areas of ecologization proposed in the work will contribute to the sustainable development of tourism, thanks to which it is possible not only to reduce the negative impact of tourism on the environment, but also to increase the level of ecological safety of the territories, as well as to more effectively implement the strategy of sustainable development.

Elimination of representative antibiotic-resistant bacteria, antibiotic resistance genes and ciprofloxacin from water via photoactivation of periodate using FeS2

The propagation of antibiotic-resistant bacteria (ARB) and antibiotic resistance genes (ARGs) induced by the release of antibiotics poses great threats to ecological safety and human health. In this study, periodate (PI)/FeS2/simulated sunlight (SSL) system was employed to remove representative ARB, ARGs and antibiotics in water. 1 × 107 CFU mL–1 of gentamycin-resistant Escherichia coli was effectively disinfected below limit of detection in PI/FeS2/SSL system under different water matrix and in real water samples. Sulfadiazine-resistant Pseudomonas and Gram-positive Bacillus subtilis could also be efficiently sterilized. Theoretical calculation showed that (110) facet was the most reactive facet on FeS2 to activate PI for the generation of reactive species (·OH, ·O2–, h+ and Fe(IV)=O) to damage cell membrane and intracellular enzyme defense system. Both intracellular and extracellular ARGs could be degraded and the expression levels of multidrug resistance-related genes were downregulated during the disinfection process. Thus, horizontal gene transfer (HGT) of ARB was inhibited. Moreover, PI/FeS2/SSL system could disinfect ARB in a continuous flow reactor and in an enlarged reactor under natural sunlight irradiation. PI/FeS2/SSL system could also effectively degrade the HGT-promoting antibiotic (ciprofloxacin) via hydroxylation and ring cleavage process. Overall, PI/FeS2/SSL exhibited great promise for the elimination of antibiotic resistance from water.

The potential and development opportunities of ecotourism in Georgia

The development of sustainable tourism in Georgia, its economic, political and social importance in the international tourism market depends to a significant extent on the development of such a type of tourism, which is in high demand today, is in the interest of the population of almost all countries and provides the opportunity to receive environmentally friendly tourist services, as well as the protection of the environment, the country's ecological safety and the preservation of biodiversity as much as possible. The main goal of the work is to study and investigate the potential of ecotourism in Georgia and the challenges in this field and the opportunities for its development. However, it is worth noting how deliberately and systematically the potential of ecotourism will be utilized and the existing opportunities will be used, which can almost completely change the current reality in terms of traditional tourism. Based on the fact that, according to various estimates, ecotourism accounts for approximately 10% of capital turnover in the international tourism business. The paper analyzes the prospects for the growth of ecotourism potential in Georgia and the positive economic and financial effects derived from it. However, ecotourism can become such a priority area of tourism that can be more beneficial than the economic and financial effects obtained from it, which is manifested in the preservation of the country's environment, natural and cultural heritage and biodiversity.

SCIENTIFIC BASIS OF MONITORING THE BOTTOM SEDIMENTS STATE AS AN INDICATOR OF THE ENVIRONMENTAL DANGER LEVEL OF HYDROECOSYSTEMS

The work proposes a method of monitoring the condition of surface water bodies that were subject to the influence of aviation industry enterprises, by studying the contamination of bottom sediments.Using the example of petroleum hydrocarbons - specific pollutants of aviation enterprises, the author proved that bottom sediments are an integral indicator of the level of manmade pollution, an indicator of the ecological safety level of hydroecosystems. The calculated coefficients of bottom accumulation indicate the progressive pollution of the reservoir and the accumulation of the main mass of pollutants in the bottom sediments. The results of studies of the small river, that flows along the airline, show that the bottom sediments belong to the category of “extremely polluted”. The structural and functional properties of bottom sediments enable us to state that, on the one hand, they contribute to the process of self-purification of the water environment by accumulating oil products, but on the other hand, bottom sediments represent a danger to the water column secondary pollution, since when physical and chemical conditions change, pollutants from the bottom sediments can pass into the water masses of the reservoir.

Simultaneous inactivation of Microcystis aeruginosa and degradation of microcystin-LR in water by activation of periodate with sunlight

Harmful algal blooms pose tremendous threats to ecological safety and human health. In this study, simulated solar light (SSL) irradiation was used to activate periodate (PI) for the inactivation of Microcystis aeruginosa and degradation of microcystin-LR (MC-LR). We found that PI-SSL system could effectively inactivate 5 × 106 cells·mL−1 algal cells below the limit of detection within 180 min. ·OH and iodine (IO3· and IO4·) radicals generated in PI-SSL system could rupture cell membranes, releasing intracellular substances including MC-LR into the reaction system. However, the released MC-LR could be degraded into non-toxic small molecules via hydroxylation and ring cleavage processes in PI-SSL system, reducing their environmental risks. High algae inactivation performance of PI-SSL system in solution with a wide pH range (3–9), with the coexisting anions (Cl−, NO3− and SO42−) and the copresence of natural organic matters (humic acid and fulvic acid), real water (lake water and river water), as well as in continuous-flow reactor (14 h) were also achieved. In addition, under natural sunlight irradiation, effective algae inactivation could also be achieved in an enlarged reactor (1 L). Overall, our study showed that PI-SSL system could avoid the inference by the background substances and could be employed as a feasible technique to treat algal bloom water.

Investigating flocculation mechanisms and ecological safety of cationic guar gum for rapid harvesting of microalgal cells

Addressing the drawbacks of traditional flocculants on microalgae biomass harvesting is crucial for large-scale industrial applications of microalgae production. In this study, cationic bioflocculant was successfully prepared by introducing cationic groups into the side chain of guar gum, achieving in-situ algae flocculation efficiency of 83.5 % with the dosage of 18.0 mg/L under pH = 10.0. Through a harmonious integration of predictive modelling and practical experimentation, a superior cell flocculation capacity of 23.5 g/g was achieved. In addition, the environmental safety and biocompatibility of cationic guar gum was assessed, using the typical suspension quantitative bacteriostatic method and the fluorescent double-staining technique. The results showed that the inhibition efficiency of Staphylococcus aureus in the system containing 60.0 mg/L cationic guar gum was only 12.0 % and there was no inhibition against Escherichia coli colonies. These findings provide a safe and green flocculant for efficient microalgae harvesting and spent medium treatment.

Acid-resistant chitosan/graphene oxide adsorbent for Cu2+ removal: The role of mixed cross-linking and amino-functionalized

Copper ions in wastewater pose a significant threat to human and ecological safety. Therefore, preparing macroscopic adsorbents with reusable and high adsorption performance is paramount. This paper used graphene oxide as the adsorbent and chitosan as the thickener. Additionally, a silane coupling agent was employed to enhance the acid resistance of chitosan, and amino-modification of graphene oxide was performed. Macroscopic adsorbents with high adsorption capacity were fabricated using 3D printing technology. The results show that all five proportions of inks exhibit good printability. Dissolution experiments revealed that all materials maintained structural integrity after 180 days across pH values. Fourier Transform Infrared Spectroscopy (FTIR) and X-ray Photoelectron Spectroscopy (XPS) confirmed the successful preparation of the materials. Adsorption experiments showed that the best performing material ratio was 8 wt% graphene oxide and 7 wt% chitosan. Adsorption kinetics and isothermal adsorption experiments demonstrated that the adsorption process occurred via monolayer chemisorption. The adsorption process was attributed to strong electrostatic forces, van der Waals forces, and nitrogen/oxygen-containing functional group coordination. Cycling experiments showed that the material retained good adsorption performance after 6 cycles, suggesting its potential for practical heavy metal treatment applications.

Ultrasonic-assisted extraction of total flavonoids from Zanthoxylum bungeanum residue and their allelopathic mechanism on Microcystis aeruginosa

Water eutrophication has emerged as a pressing concern for massive algal blooms, and these harmful blooms can potentially generate harmful toxins, which can detrimentally impact the aquatic environment and human health. Consequently, it is imperative to identify a safe and efficient approach to combat algal blooms to safeguard the ecological safety of water. This study aimed to investigate the procedure for extracting total flavonoids from Z. bungeanum residue and assess its antioxidant properties. The most favorable parameters for extracting total flavonoids from Z. bungeanum residue were a liquid–solid ratio (LSR) of 20 mL/g, a solvent concentration of 60%, an extraction period of 55 min, and an ultrasonic temperature of 80 °C. Meanwhile, the photosynthetic inhibitory mechanism of Z. bungeanum residue extracts against M. aeruginosa was assessed with a particular focus on the concentration-dependent toxicity effect. Z. bungeanum residue extracts damaged the oxygen-evolving complex structure, influenced energy capture and distribution, and inhibited the electron transport of PSII in M. aeruginosa. Furthermore, the enhanced capacity for ROS detoxification enables treated cells to sustain their photosynthetic activity. The findings of this study hold considerable relevance for the ecological management community and offer potential avenues for the practical utilization of resources in controlling algal blooms.

Suitable habitat evaluation and ecological security pattern optimization for the ecological restoration of Giant Panda habitat based on nonstationary factors and MCR model

Enhancing the regional connectivity, coordination, and integrity of Giant Panda National Park can protect giant pandas. The construction and optimization of the ecological security pattern in giant panda habitat can effectively promote the information exchange among giant panda populations of Giant Panda National Park in Ya'an area. Based on climate change, geographic location, human activities, and other factors, the Maxent model was used to evaluate the non-stability of giant panda habitat suitability, and the minimum cumulative resistance (MCR) model was used to construct the ecological security pattern. Based on the gravity model and relevant image verification analysis, we proposed an optimal solution to the ecological problem of giant panda corridor groups. From our research, good habitat suitability of giant pandas was detected, with a high degree of local fragmentation. The areas of the most suitable habitat, the more suitable habitat, and the generally suitability were 1970.12 km2, 2346.51 km2, and 1902.37 km2, respectively. Suitable habitat was located between 2100 m and 3400 m in elevation, with a less than 30° slope. The average temperature of the coldest season in the suitable area was around - 2 ∼ 2 °C, the precipitation of the wettest month was between 140 ∼ 160 mm, and the mean diurnal range was between 9 ∼ 14 °C. Valuation results for nonstationary factors beyond these ranges will not fall within the Habitat Suitability Zone. In total, 13 ecological sources, 13 ecological corridors, 6 ecological barrier points, and 4 ecological pinch points were identified and divided into 4 ecological corridor groups to locate and repair ecological problems, achieving the purpose of building and optimizing ecological security patterns. The integrated technical frame work proposed in this work, which combined the suitability evaluation, ecological safety pattern construction and ecological restoration, considered the nonstationary variations in factors and the actual species ranges. It also emphasized the importance of the relationship between the species’ suitability and the ecological security pattern. The results of this work have important implications for examining the habitat modifications, gene exchange between giant panda populations, and habitat conservation of giant pandas.