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Extreme Flood Calibration and Simulation Using a 2D Hydrodynamic Model Under a Multipurpose Reservoir Full text
2023
Chinar Garg and Ananda Babu K.
Extreme floods have become common in Asian cities, with recent increases in urbanization and extreme rainfall driving increasingly severe and frequent events. Understanding the flood dynamic is essential for developing strategies to reduce risk and damage, thus ensuring the city’s protection. Channel roughness is a sensitive parameter in developing a hydraulic model for flood forecasting and flood inundation mapping. A High-resolution 2D HEC-RAS model was used to simulate the flood events of 1994, 1998, 2002, 2006, and 2015. The calibrated model, in terms of channel roughness, has been used to simulate the flood for the year 2006 in the river. The performance of the calibrated HEC-RAS-based model has been accessed by capturing the flood peaks of observed and simulated floods and computation of root mean squared error (RMSE) for the intermediated gauging stations on the lower Tapi River. Results revealed that there is good agreement between simulated and observed floods.
Show more [+] Less [-]Protection of the Environment Under Trade and Investment Agreements: An Analysis Based on Existing Legal Frameworks Full text
2023
Kudrat-E-Khuda (Babu), Nazia Afroz Ananna and Arghyadeep Chakraborty
Free trade causes damage to the environment substantially as it puts pressure on natural resources in its venture to expand economic activities. On the other hand, there is also an argument that free trade has the potential to improve environmental quality by contributing to growth. Such growth enhancement may help individuals, organizations, or governments raise funds and spend more on environmental protection. This paper highlights the links between trade and the environment. Besides, it also shows how international trade and environmental protection are both essential to the well-being of humanity and, conversely, how they are mutually supportive. This paper also scrutinizes how the WTO plays a role in balancing trade and the environment, as many WTO agreements have environmental exceptions.
Show more [+] Less [-]Anaerobic Biodegradability Potential of RCF-Based Kraft Paper Mill Effluent Full text
2023
Abhishek Tyagi, Amitabh Raj Tripathi, Pratibha Naithani and M. K. Gupta
The present study collected anaerobic sludge from a paper mill operating a UASB reactor on agro-based raw material (wheat straw) washings for biogas production. After determining the sludge profile and methanogenic activity of anaerobic sludge, it was further used to determine the anaerobic biodegradability of RCF-based kraft paper mill effluent. The sludge profile of collected anaerobic sludge was found w.r.t. Suspended Solids (SS) 60 g.L-1, Volatile Suspended Solids (VSS) 23 g.L-1, Inorganic content 62% & Organic content 38%. The presence of effective microbes in anaerobic sludge was confirmed by SEM (Scanning Electron Microscope). Degradation of organic matter present in effluent by anaerobic digestion leads to the production of biogas (methane & CO2), a renewable energy source. The sludge profile and methanogenic activity findings supported the anaerobic treatment of kraft paper mill effluent and were positive. The methanogenic activity of anaerobic sludge was determined as 0.832 gCOD.gVSS-1×Day, and the average anaerobic biodegradability of RCF-based kraft paper mill effluent was found to be 71.5%.
Show more [+] Less [-]Isolation and Screening of Probiotic Bacteria from the Gut of Polychaetes as a Probiotic Potential for Fish Aquaculture Full text
2023
S. Balasubramanian, T. Bettin Thomas, D. Mathavan, R. Sathish Kumar, G. Uma, R. D. Stevens Jones and T. Citarasu
In the present study, a total of 17 morphologically different gut-associated bacteria were isolated from four species of estuarine polychaetes: polychaetes Capitella capitata, Scalibregma inflatum, Dendronereis aesturiana, and Namalycastis abiuma. The isolated strains were evaluated for their probiotic activities, such as digestive enzymes including protease, amylase, and lipase, and antimicrobial activities by the agar well diffusion method against fish pathogens. Based on their better enzymatic and antibacterial activities, two bacterial strains, CMST Poly1 and CMST Poly2, were selected for further probiotic studies. Based on the biochemical and morphological characterization, both probiotic strains were characterized as Gram-positive, rod-shaped, non-motile, non-spore-forming, homofermentative, absence of catalyzing enzymes and notable proteolytic activity, and susceptibility to various antibiotics. Further, these two strains were confirmed by 16S rRNA gene sequence analysis as Bacillus subtilis CMST Poly1 and Priestia megaterium CMST Poly2. Our results revealed that strains Bacillus subtilis CMST Poly1 and Priestia megaterium CMST Poly2 can potentially be used as probiotic strains in aquaculture applications.
Show more [+] Less [-]Investigation of Adsorption of Nd(III) on Boron Nitride Nanosheets in Water Full text
2023
C. Fu, Y. He, C. Yang, J. He, L. Sun, K. Du, X. Zhang, G. Sheng, L. Li, L. Wang and W. Linghu
In this paper, boron nitride materials were prepared by a two-step synthesis method, and this material’s adsorption property for neodymium ions was explored. The experimental results show that the adsorption capacity of boron nitride is closely related to pH. When the pH is 6.0, the adsorption performance of the material is the best; the kinetic data show that the adsorption equilibrium can be reached in about 150 min, and the adsorption capacity at equilibrium is 207.3 mg.g-1. In addition, the Freundlich and Langmuir models were used to fitting the thermodynamic results. It was found that the adsorption process of boron nitride on Nd(III) involved both monolayer adsorption and multi-layer adsorption. These data indicate that boron nitride has a good adsorption effect on Nd(III) in water and is a promising material for environmental remediation.
Show more [+] Less [-]Experimental Aeration Investigations on Supersaturated Total Dissolved Gas Dissipation Full text
2023
Yuanbo Yao, Huixia Yang, Yunyun Wang, Jiajia Liang and Ling Yang
Supersaturation of total dissolved gas (TDG) is mainly produced by high dam discharge, excess oxygen production by plant photosynthesis, and a sharp increase in water temperature, which may directly lead to fish and aquatic organisms suffering from “gas bubble disease” (GBD) or death. Aeration was one of the methods used to solve the dissipation of supersaturated TDG. In this paper, aeration had an obvious promotion effect on the dissipation of supersaturated TDG. For the calculation and analysis of supersaturated TDG dissipation coefficient, the aeration rate was proportional to TDG dissipation coefficient and had a promoting effect on it, while the aeration depth and aeration aperture were inversely proportional to TDG dissipation coefficient and played an inhibitory effect on it. The supersaturated TDG dissipation coefficient was affected by a factor of KTDG,Q> KTDG,D> KTDG,H. A quantitative relationship between the supersaturated TDG dissipation coefficient and aeration rate, aeration depth, and aeration aperture was obtained, respectively, as well as important expressions with comprehensive effect factors; their margins of error average within 10%. This research method has an important guiding significance for improving the living environment of fish and other aquatic organisms, alleviating the adverse effects of supersaturated TDG.
Show more [+] Less [-]Study on the Temporal and Spatial Distribution of Air Pollutants in Typical Cities of China Full text
2023
He Tao and Tihao Hou
The present study selects cities such as Zhengzhou, Kaifeng, Anyang, Hebi, Xinxiang, Jiaozuo, and Puyang along the Yellow River Basin in Henan Province. The data of six pollutants, such as PM2.5, PM10, SO2, CO, NO2, and O3, in various cities from 2019 to 2021, and the monthly primary pollutant data of seven cities in the past five years were collected through various channels. The air quality of the above seven cities was analyzed with the spatial-temporal distribution of pollutants as the research objective and geographic information system as the research tool. The results show that affected by the distribution of key pollution sources and meteorological conditions in the urban area, the PM2.5 concentration generally shows a zonal feature of decreasing from northwest to Southeast. The high-value area is located in the north and west of the integrated area of the seven cities, and the low-value area is located in the Southeast of the seven cities.
Show more [+] Less [-]The Potential of Phytoremediation to Treat Different Types of Wastewater - A Review Full text
2023
Vijayant Panday and
Globally, with an increase in population, water demand is also increasing, but on the other hand, water availability is continuously decreasing due to various factors. Contamination of existing water bodies is the main factor for the freshwater shortage. Conventional methods are there to treat polluted water, but their construction and operational cost are very high. Phytoremediation is an economical, solar-driven, green plants (macrophytes) based, environment-friendly technology being researched worldwide. Many researchers contributed to identifying the potential of phytoremediation to treat different types of wastewater. Along the same line, an attempt has been made with this literature survey to contribute to technological advancement. The study results showed that water hyacinth plants could potentially treat almost all types of wastewater. Still, their use with other plants like Phragmites australis, Azolla filiculoides, Lemna minor, Typha latifolia, etc., as polyculture (mixed culture) could perform way better than the individual. It not only improves the efficiency of phytoremediation but also helps some plants to grow and perform for a long duration when used in mixed culture.
Show more [+] Less [-]Comparative Advanced Oxidation Decolorization of the Triphenylmethane Dye with Dimethyl Dioxirane and Hydrogen Peroxide Full text
2023
S. Vinotha and A. Leema Rose
Methyl Violet (MV), a triphenylmethane dye, has been subjected to comparative studies with hydrogen peroxide and dimethyl dioxirane under optimum situations. When employing hydrogen peroxide, the photolysis process becomes slower, but the dye solutions are entirely decolored and mineralized. The decolorization rate exhibits pseudo-first-order kinetics. The effect of pH, oxidant dosage, and methyl violet concentration on the degradation is also examined. Generated o-leucoaniline,1,3-diphenylurea,2-hydroxy benzoic acid, phenol, acetone, water, carbon dioxide, and carbon monoxide are identified and measured by GC-MS analysis. These substances remain in the dye solution along with dimethyl dioxirane, which is released faster during the last stages of degradation. The degradation rates of methyl violet reached 97.9% and 65.8% within 30 mins and 180 min of reaction time using dimethyl dioxirane and hydrogen peroxide.
Show more [+] Less [-]The Impact of Climate Change, Economic Growth, and Population Growth on Food Security in Central Java Indonesia Full text
2023
Suryanto Suryanto, Irwan Trinugroho, Fitri Susilowati, Jean Baptiste Aboyitungiye, and Yuaninda Hapsari
As climate change continues to cause more frequent weather shocks such as droughts and floods and increasingly erratic rainfall, people in developing regions are threatened by crop failures and hunger. In this study, the researchers describe how climate change influences food security in Central Java, seen from the frequency of floods, rainfall, and rainy days. This study also added another variable, i.e., economic growth, reviewed through GRDP and the amount of rice production. Using the Common effect model, the study results revealed that rainy days and population were the variables significantly influencing food security in cities/regencies in Central Java Province. Meanwhile, two other variables, i.e., rainfall and GRDP, had no significant effect on food security in cities/regencies in Central Java Province.
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