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Utilization of Enterobacter cloacae WW1 Biomass for Biosorption of Lead(II) from Aqueous Solution
2023
Thongkrua, S. | Kasuya, A.
The present study evaluated lead biosorption by Enterobacter cloacae WW1 isolated from tannery wastewaters under different initial Pb2+ concentrations, biomass concentrations, and contact times. The results showed that at an initial Pb2+ concentration of 80 mg.L-1, the optimal conditions for living cells were a biomass concentration of 7 g.L-1 and a contact time of 120 min. For non-living cells, biomass was a biomass concentration of 4 g.L-1 and contact time of 45 min, which provided removal efficiencies of 92.03 ± 0.10% and 99.51 ± 0.01%, respectively. The maximum biosorption capacity obtained for non-living cells using an initial Pb2+ concentration of 640 mg.L-1 was 76.65 ± 0.05 mg.g-1. The equilibrium data followed the Langmuir and Freundlich models for living cells, and the data for non-living cell biosorbents fit the Langmuir model. The biosorption kinetics for living and non-living cells fit well with a pseudo-second-order kinetic equation. SEM-EDX analysis clearly showed the morphology and presence of Pb2+ particles on non-living cell surfaces after biosorption. In addition, the results revealed that functional groups such as hydroxyl, amino, carboxyl, amide, and phosphate groups on the bacterial cell surface detected by FTIR were associated with the binding of Pb2+ ions. The results indicated that E. cloacae WW1, a lead-resistant bacterium, can be used as an alternative biosorbent for lead removal from wastewater.
Afficher plus [+] Moins [-]Economic Valuation and Benefit Transfer of Restoring the Teesta Riverine Ecosystem
2023
Tamang, Pravesh
This study seeks to understand the socio-economic and ecological impacts of the hydroelectric power projects along the upper basin of the river Teesta in Sikkim. This study estimates the non-market benefits of restoring the Teesta riverine ecosystem and evaluates the transferability of welfare estimates. This study is a first of its kind undertaken in the Teesta basin which uses a unique dataset of 830 households obtained from the affected regions of the river basin. During the study, nine villages adjacent to the river Teesta, dams, and powerhouses were identified and surveyed. Double bounded dichotomous choice questions were used to elicit willingness to pay (WTP). Both the logistic and normal distribution models were fitted and the results were mostly similar. The median WTP was INR 373.00 and the variables that described the rating on dams, ownership of property, monthly expenditure of the household, informal employment status, and satisfaction about the state of the river Teesta were among the significant variables in the model. The benefit function value transfer estimated was INR 232.00 with the percentage transfer error (PTE) of 61.9%.
Afficher plus [+] Moins [-]Performance of Alum Coagulation and Adsorption on Removing Organic Matter and E. coli
2023
Hidayah, E. N. | Cahyonugroho, O. H. | Fauziyah, N. A.
Surface water is the primary resource for raw water in drinking water treatment processes. Therefore, the presence of microorganisms, bacteria, and viruses should be the main focus in drinking water treatment, in addition to natural organic matter, which is composed of organic carbon groups derived from aquatic biota as well as organic material, organic matter from industrial and domestic waste. This study applied coagulation-flocculation followed by adsorption as the advanced treatment with activated carbon for removing organic matter and bacteria simultaneously to know each process’s performance. The results indicated that all treatment processes have a good performance for removing dissolved organic matter in water with efficient removal of 28.35%-70.75% of TOC concentration and 26.75%-55.95% of UV254 concentration. Further, the selected processes demonstrated a high percentage of removal of E. coli, about 65.35%-96.43%. However, the effect of chlorination impacted the increasing THMs concentration up to 36.32%, while the other processes could remove THMs concentration 17.25%-51.08%. Overall, this study conjectures that all treatment processes simultaneously perform well for removing dissolved organic matter, THMs, and E. coli. However, chlorination should be managed to control the formation of THMs due to the remaining organic matter in water.
Afficher plus [+] Moins [-]Variability and Trend in Summer Monsoon Rainfall and its Correlation with Crop Yield in the Districts of Andhra Pradesh During 2011-2020
2023
Kavitha, Chandu | Raju, A. Dharma | Kumar, S.V.J.
In the context of climate change and its impact on agriculture, the paper analyses the trend of monsoon rainfall and its correlation with crop yield in Andhra Pradesh. The summer monsoon is the main rainy source of water for the state of Andhra Pradesh. The Kharif crops depend on the southwest monsoon rains to the extent that its adverse variability may lead to water stress and agrarian crisis. It has been observed from the study that in recent years the contribution of monsoon rainfall during September is increasing, and any harvest during the month is correspondingly affected, leading to a decline in the crop yield.
Afficher plus [+] Moins [-]Identification and Characterization of Aluminium Tolerant Bacteria Isolated from Soil Contaminated by Electroplating and Automobile Waste
2023
Bisht, H. | Kumar, N.
Due to anthropogenic activities and the advancement of industries, metal contamination is growing globally. Aluminum toxicity is seriously endangering plants, animals, and humans by rapidly rising in soil and water. Even though some fungi can tolerate aluminum, researchers are interested in finding bacteria that are resistant to aluminum. The current state of knowledge on bacteria resistant to aluminum is extremely limited. In the present study, bacterial isolates from soil near a metal electroplating and automobile industry in Punjab, India, were isolated and then screened for high aluminum metal tolerance. The aluminum tolerant bacterial isolate was identified as Cedecea davisae M1, a member of the Enterobacteriaceae family, using morphological, biochemical, and 16srRNA gene sequence analyses. The spectroscopic results indicate that the strain may tolerate up to 150 ppm of aluminum. Antibiotic resistance of Cedecea davisae M1 was determined using disks on Luria agar plates, and the bacteria were found to be resistant to vancomycin, ampicillin, carbenicillin, and rifampicin. The findings of the study indicated that the strain might be able to remove aluminum toxicity from the environment, which needs to be further explored.
Afficher plus [+] Moins [-]Microplastics: What Can We Learn from Clastic Sediments?
2023
Waldschläger, Kryss | Brückner, Muriel Z.M. | Almroth, Bethanie Carney | Hackney, Christopher R. | Adyel, Tanveer M. | Alimi, Olubukola S. | Belontz, Sara L. | Cowger, Win | Doyle, Darragh | Gray, Andrew | Kane, Ian | Kooi, Merel | Kramer, Matthias | Lechthaler, Simone | Michie, Laura | Nordam, Tor | Pohl, Florian | Russell, Catherine | Thit, Amalie | Umar, Wajid | Valero, Daniel | Varrani, Arianna | Warrier, Anish K. | Woodall, Lucy C. | Wu, Nan
Microplastics research has gained momentum in the 21st century but lags behind the long-standing research on clastic sediment. An interdisciplinary review paper was conducted, comparing microplastics with natural sediments in terms of particle properties, transport processes, sampling techniques, and ecotoxicology. The paper identifies seven research goals to enhance our understanding of microplastics in freshwater environments while learning from sediment research. This extended abstract presents the core message of the review paper, emphasizing the need to improve descriptions of microplastic particles, understand their transport processes, develop standardized sampling methods, and study their ecotoxicological effects. The research goals outline specific tasks to achieve these objectives and emphasize the importance of comparing microplastics to sediments to gain insights into their toxicity. Addressing these research goals will contribute to a comprehensive understanding of microplastics and their impact on freshwater ecosystems. For detailed insights, the original paper should be consulted.
Afficher plus [+] Moins [-]The Vertical Distribution of Riverine Microplastics: The Role of Turbulence
2023
Alzawaidah, H.Z.A. | Vermeulen, B. | Waldschlager, K.L.
Owning to plastics high durability and resistance to degradation.
Afficher plus [+] Moins [-]Biomonitoring with bryophytes in managed forested areas. Three examples from the southern Italian Apennines
2023
Three sites in the southern Italian Apennines were selected to assess correlation between forest structure and bryophyte flora. In two of the sites, the Index of Air Purity (IAP)–based on cover data of epiphytic bryophytes–was evaluated. The results show that bryophyte populations–and consequently IAP–are affected by forest structure and development, and that studies including different sites require a precise assessment of silvicultural characteristics to allow comparisons. Indicator values of mosses and liverworts were also taken into consideration in characterizing ecologically the three sites.
Afficher plus [+] Moins [-]Effects of anthropogenic and environmental stressors on the current status of red mullet (Mullus barbatus L., 1758) populations inhabiting the Bulgarian Black Sea waters
2023
The red mullet (Mullus barbatus Linnaeus, 1758) is a keynote species for the Bulgarian Black Sea ecosystem and fisheries; nevertheless, existing knowledge on population status is very scarce. The present study was intended to assess the health status and adaptive potential of M. barbatus populations inhabiting the Bulgarian waters of the Black Sea. Our findings revealed that populations of M. barbatus are exposed to a variety of anthropogenic and environmental stressors. The species’ status was assessed using representative genetic, morphological, biochemical and chemical biomarkers from specimens obtained in the research area’s northern and southern regions. Based on mtDNA markers, genetic analysis revealed low haplotype and nucleotide diversity, typically observed in overexploited or “threatened” populations. Examining the morphology of the specimens revealed no discernible pattern of differentiation. Except for aluminium and chrome, metal and PAH concentrations in fish were below the regulatory thresholds. The specimens from the southern region ingested more microplastics than those from the northern region. The majority of specimens collected from the southern region also exhibited elevated levels of oxidative stress and decreased antioxidant defence, which can be interpreted as an early indication that they had reached the limits of their adaptive potential. Further research on the composite effects of the stressogenic environment on the Black Sea biota are critically needed, as well as the introduction of new indicators and thresholds at molecular and cellular levels for adequate monitoring of both the ecological state of the marine environment and its biota.
Afficher plus [+] Moins [-]A baseline assessment of anthropogenic macrolitter on dunes along the Bulgarian Black Sea Coast using visual census and Unmanned Aerial Systems
2023
Beach-dune systems are among the most dynamic and sensitive elements of coastal ecosystems in the world. They represent an intersection between human activities, flora, fauna and economic interests in tourism. The Bulgarian Black Sea shoreline spans 518.7 km and comprises 131 km (25%) of the depositional coast, including beaches and 46 dune systems. Over the past three decades, heavy anthropogenic impacts have been observed, significantly altering the cleanliness of the beach-dune systems along the Bulgarian Black Sea Coast (BBSC). The research initially began as an initial assessment of macrolitter on dunes (MLD) using Unmanned Aerial Systems (UAS). However, due to concerning data obtained in the first year, it transitioned into a mid-term monitoring program conducted between 2018 and 2022. The baseline assessment is based on a visual census, UAS mapping and manual image screening procedure in a GIS environment for litter mapping in 40 areas of litter monitoring (ALMs) along the Bulgarian Coast. Throughout the five-year monitoring period, the most abundant type of MLD was “Artificial polymer materials,” accounting for 83.4% of the total number, followed by “Paper/Cardboard” (6.2%), “Glass/Ceramics” (2.8%), “Metal” (2.8%), “Processed/Worked wood” (1.83%), “Rubber” (1.29%), and “Cloth/Textile” (1.17%). Generally, 95% of the total litter amount was assessed from Land-based sources and 5% from Sea-based sources. The COVID-19 pandemic indirectly affected the cleanliness of the Bulgarian dunes due to restrictions on foreign travel, which increased the domestic tourist pressure on the Bulgarian beaches, resulting in a more significant amount of waste accumulating on the beaches and dunes. The abundance experienced an increase of 39% between 2018 and 2021. A similar upward trend (+41%) was observed in the density of macrolitter on the dunes. Based on visual census data, the average density was estimated to be 0.54 ± 0.35 items/m2. The spatial distribution of MLD is a complex combination of anthropogenic impact and wind processes that affect various eco-geomorphological elements of the beach-dune system. The embryonic dunes retained only 16% of the total items (Dav: 0.32 ± 0.12 items/m2). The highest litter density was registered on the foredunes (Dav: 0.71 ± 0.21 items/m2; 28% of total items). The backdunes contained the highest litter abundance, accounting for 55% in larger areas (Dav:0.59 items/m2). Density litter maps established that dune vegetation acted as a natural trap, retaining 40% more macrolitter compared to areas without dune plants. A Clean Dune Index (CDI) was developed to evaluate the cleanliness of Bulgarian dunes. Based on aggregated CDI data for 2018–2022, the cleanliness of the dunes along the Bulgarian Coast was categorised as “moderate” (CDIav:10.89). Dune systems near the most visited resorts were classified as “extremely dirty”, with the highest CDI values recorded at Kavatsite (27.22), Nessebar – South (25.01), Bolata (24.69), Asparuhovo - Varna (24.33) and Slanchev bryag (24.09). On the other hand, the dune systems at Ropotamo and Lipite were rated with the lowest CDI – 0.95 and 1.2. Dunes are sensitive habitats and require minimal anthropogenic impact, which requires the intensification of the use of high-resolution remote sensing methods for litter mapping. The quality of the presented data and the results obtained outline drones as a future primary tool for beach and dune surveys.
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