Environmental Quality Management最新文献

This study evaluated the ability of the red microalga Porphyridium cruentum in removing polyethylene terephthalate (PET) microplastics (MPs) from aquatic systems through a hetero-aggregation mechanism mediated by exopolysaccharides (EPS). Results showed that PET MPs exposure to microalgae at concentrations of 100, 200, and 300 mg/L for 30 days notably reduced microalgae growth at higher concentrations. Conversely, increased PET MPs concentration increased EPS production by microalgae as a defense response to oxidative stress. The highest EPS production was obtained at a 300 mg/L PET MPs exposure, concentration of 4.349 g/L. FTIR analysis showed EPS was rich in negatively charged carboxyl and sulfate groups, electrostatically interacting with positively charged PET MPs, forming stable flocculating hetero-aggregates. The removal efficiency of PET MPs reached 95.8%–97.5%, with the highest efficiency obtained at a concentration of 200 mg/L PET MPs, demonstrating the effectiveness of P. cruentum in removing PET MPs from water environment. SEM analysis confirmed the formation of a solid EPS matrix encasing the MPs particles and the absence of markedly structural changes in the EPS post-interaction confirmed through FTIR. These findings underscore the potential of microalgae as an eco-friendly and energy-efficient biological solution for MPs remediation in aquatic environments.

Water quality is a stern issue in urban areas because it is indispensable for the sustenance of life. The present study aimed to determine the spatial trends with time in water quality attributed to transitioning anthropogenic land-use/cover in a Himalayan city—Dehradun, India—through the Weighted Arithmetic Water Quality Index (WQI). A total of 36 samples from nine surface aquifers during four seasons were analyzed for physicochemical and biological water quality parameters and compared with standards prescribed by BIS—Bureau of Indian Standards and WHO—World Health Organization. The water quality categorization during the monsoon (good–moderate), post-monsoon (poor–very poor), and the winter and premonsoon seasons (poor–unfit) reveals the temporal trends. Further, WQI values indicate that 25% of the water samples (urban) were in the very poor–unfit category, 52% in poor (semi-urban), and 22.2% in good status (rural), with elevated values for Coliform bacteria at all locations. Unsustainable anthropogenic activities, namely, discharge of wastewater, indiscriminate dumping of solid waste, and fecal matter, are the main factors, which have negatively impacted the water quality of these rivulets. Land-cover analyses from 2002 to 2023 observed an increase in settlement—urban built-up (+7.5%), cultivated land (+7.5%), and barren land (+4.4%), whereas grassland (−8%), forest (−12%), and water bodies (−0.11%) decreased in terms of area coverage, with a slight decline in land surface temperature regimes attributed to the aerosol optical depth variations. The management of water resources (catchment basin conservation) in the Dehradun region is a major concern pertaining to urban land use planning and the mandate of Sustainable Development Goals (SDGs) 6 and 11.

The rising global plastic waste crisis, driven by increasing production and consumption, threatens environmental sustainability and non-renewable resource availability as 4% of global oil is being used as feedstock for plastics manufacturing, exacerbating the potential supply risk for crude oil as non-renewable resource, increasing wastes in the environment and partly contributing to global rise of oil prices. To address these challenges, sustainable consumption approaches are crucial such as reverse logistics implementation. Existing reverse logistics (RL) frameworks often fail to capture the complex adaptive nature of RL systems, which involve multiple interdependent actors and dynamic flows. This study develops a Reverse Logistics Implementation Framework using an Interpretive Structural Modeling (ISM) approach, integrating insights from literature and expert opinions. Findings reveal that RL implementation is most effective when viewed as a complex adaptive system, emphasizing the role of resource competencies, infrastructure, reverse supply networks, adaptability, and regulatory frames. The proposed framework provides strategic guidance for policymakers, supply chain managers, and logisticians, ensuring structured RL adoption across sectors.

This study describes the production of Ag and ZnO nanoparticles (NPs) by green synthesis from Vitis vinifera L. extract and their incorporation into HIPS to finally prepare nanocomposites. AgNO₃, ZnCl₂ and (Zn(O₂CCH₃)₂) were used as metal precursors. The FTIR spectra of Ag NPs revealed that several organic compounds impregnated them; meanwhile, ZnO NPs exhibit a Zn-O characteristic band. The x-ray diffractometer revealed intense peaks that corresponded to the fcc structural features of Ag and the wurtzite phase to ZnO. DLS determined the size of the NPs with monomodal curves for both materials; the average size was 179 nm for AgNPs, while ZnO showed 324 nm. Nanocomposites based on high-impact polystyrene (HIPS) containing metallic NPs of silver and zinc oxide (AgNPs and ZnO NPs) with 0.5% and 1.5% concentration were prepared without essential changes in %gel. The most relevant changes occurred in impact resistance properties and elastic modulus when the filler was incorporated into the polymer matrix. MFI and glass transition do not present significant variations after composite preparation.

This study investigates the treatment efficiency of Chrysopogon zizanioides (vetiver grass) in improving surface water quality through phytoremediation, complemented by machine learning-based water quality classification. Water quality index (WQI) and water quality classification (WQC) were anticipated and classified using a machine learning model by filtering used Chrysopogon zizanioides. Surface water samples were collected and monitored at regular intervals every 7 days over a period of 12 weeks to ensure sufficient temporal resolution for tracking dynamic changes in key parameters such as pH, turbidity, hardness, chloride, sulfate, calcium, TDS, TSS, iron, and copper. The results show that the proposed models accurately estimate the WQI and categorize water quality with improved robustness. The study found that the NARNN model predicted WQI values better than the LSTM model. Additionally, the XGBOOST algorithm had a maximum accuracy rate of 97.01%. It also has a 99.23% sensitivity rate, confirming positive detection. With a specificity rating of 97.78%, the system accurately identified negative events. The precision rate was 94.93%, suggesting its ability to predict positive events. Finally, the algorithm's F-score of 98.54% indicates its WQC prediction performance. This study integrates ecological restoration, technology, and community-focused solutions to provide clean water access and sustainable water management to achieve the United Nations Sustainable Development Goals (UN SDGs 6).

This study explored an all-inclusive overview of research based on carbon materials for application in CO₂ capture and conversion (CCC) within the past 18 years (2006–2024). The study covered and analyzed 1680 research articles on carbon materials for CCC. Various aspects, such as publication countries, affiliations of the authors, high-impact journals, different areas of research, and key issues attracting discussions in the field, were examined. The results of the study reveal a significant rise in the interest in carbon-based materials for CCC. The top 10 countries with the highest number of publications were led by China with 902 publications. On international collaboration, which defines the total link strength (TLS), China, the United States, and South Korea rank first, second, and third, respectively. The Chemical Engineering Journal excels with a substantial publication volume of 76 articles. The study also discovered that the traditional activated carbon was advanced to a material like graphene and carbon nanotubes (CNTs). This advancement emphasizes the rising concern in addressing CO₂ management challenges. However, substantial challenges persist, including attaining the optimum performance and scalability while integrating CO₂ capture with conversion processes. Thus, there is a crucial need to enhance affordable pre-treatment processes, improve stability, and address the impact of contaminants. Future research should focus on advancing study quality and quantity, strengthening TLS, and encouraging interdisciplinary approaches.

Kebumen Regency's areas are dominated by shrimp ponds and other anthropogenic activities along the coast. Waste material usually generated from these coastal activities. Plastic waste that disposed of into the environment eventually end up in water areas. The marine debris degrades into microplastics. Degraded microplastics can be found in coastal sediments. This study aims to determine the concentration and distribution of microplastics in sediment at the coastal areas of Kaliratu Beach. In situ sampling were conducted on seven site locations regarding the proporsional location due the waste resources. The 2D hydrodynamics modeling approach with Mike 21 software was applied to model the spatial distribution of microplastics movement concerning east moonsoon seasons. The result showed that the concentration of microplastics on Kaliratu Beach ranged from 25 to 57.5 particles/kg. The contamination of microplastics found includes types such as fibers, fragments, films, and pellets, with various colors and sizes. The polymers constituting these microplastics are polyamide and polyester. Microplastics enter coastal areas through several means, such as river runoff, wind, and being carried by tidal currents, which provide exploratory result comparing to the other location. The distribution of microplastics was modeled using hydrodynamic modeling and particle tracking.

The main bottleneck found in microbial fuel cells (MFC) is substrate loss due to unwanted microorganisms, which will reduce the electron transfer and hence coulombic efficiency (CE). Methanogens present in the inoculum competitively inhibit the process of electrogenesis, thereby reducing power output. There are various methods established to inhibit the methanogens or to suppress methane production. Among that, the inhibition methods using medicinal plant metabolites are very prevalent. The allicin compound present in garlic extract is reported to inhibit methanogens and hence can be used as a pretreatment agent, which would enhance the performance of MFC. During long-term operation, to enrich the electrogens to maintain a stable microbial biofilm and suppress the methanogens, unwanted microorganisms in the anodic inoculum should be removed. The combination of extract pretreatment and inoculum removal strategies has been employed in this study to ensure long-term improved performance. A significant reduction in the methanogenic population of the anaerobic sludge inoculum could be obtained with garlic extract pretreatment. A maximum CE (20%) and maximum power density (8.4 W/m³) could be obtained while using garlic extract pretreated inoculum in MFC. The CE further improved to 31.7% with the removal of sludge inoculum from the MFC. An increase in bio-electrochemical activity on the anode was observed during cyclic voltammetry and linear sweep voltammetry after the sludge was removed from the system. In addition, the Congo red dye degradation rate was also found to be enhanced using this strategy, which is found to be sustainable.