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An Attempt to Reduce the Electrocoagulation Costs and to Ensure the Reuse of Treated Aqueous Dye Solution Texto completo
2023
D. Jovitha Jane, M. S. Asath Murphy, Riju S Robin, S Sahaya Leenus, Jegathambal Palanichamy and Parameswari Kalivel
In most of the research works, similar metal electrodes were used, resulting in high operating costs, and the reuse of the treated water was not explored. The major goal of this research is to lower the cost of the electrocoagulation (EC) process by employing electrodes made of different metals and to investigate whether it is possible to reuse the water that has been treated by doing so. It was done to optimize the operational parameters such as pH, voltage, time, electrolyte, and dye concentrations. The energy and electrode consumption was calculated as 0.29 kWh.m-3 and 3.5×10-2 kg.m-3, respectively. The HPLC and LC-MS studies shows the degradation of dye and the formation of intermediary compounds, which were less toxic. The sludge obtained from the EC process was subjected to EDX and XPS analysis to know the composition of metals and the formation of metal hydroxide coagulants. The phytotoxicity of the treated water after EC was examined using Trigonella foenum-graecum seeds. The results showed an utmost color removal efficiency (CRE%) and COD removal of 99.78% and 92.86% with an operating cost of US$ 0.028, which is comparatively 98.12% lower than the other conventional electrodes. The treated toxicity test of water was comparable to the toxicity test of tap water.
Mostrar más [+] Menos [-]Negative Effects of the Urban River Pollution on the Environment and Human Health in Bangladesh Texto completo
2023
Kudrat-E-Khuda (Babu), Md. Riaduzzaman, Tahmina Akter and Sumaia Akther
Based on research findings, Bangladesh’s river water, crucial for domestic, agricultural, and industrial use, has long been in a terrible situation. There have been numerous instances of significant contamination in the waterways surrounding Dhaka city, including the Buriganga River, and in Chattogram city, including the Karnaphuli River, over the past 40 years. The existing data demonstrate that other urban rivers, particularly Karatoa, Teesta, Rupsa, Pasur, and Padma, are also in severe condition due to the disposition of huge pollutants. Contaminants flowing with the water have severely polluted the downstream areas of the rivers. High metal concentrations are frequently observed in river water during the dry season. In the Buriganga River and at certain locations in the Turag, Balu, Sitalakhya, and Karnaphuli Rivers, the presence of dissolvable oxygen (DO) is nearly zero. NO3, NO2, and PO4-3 pollution has also occurred in many rivers. Most rivers have Cr, Zn, Fe, Pb, Cu, Cd, Mn, As, and Ni concentrations beyond the legal limit for drinking water. In contrast, some rivers have metal concentrations above the legal irrigation water limit. The majority of the rivers, particularly the peri-urban rivers in Dhaka city, Teesta, Korotoa, Rupsha, Karnaphuli, and Meghna Rivers, have significantly higher metal concentrations, according to sediment data. Metal concentrations in sediment are generally higher than USEPA standards in most rivers. Metal concentrations in fish and crops demonstrate metal bioaccumulation. The trend in metal concentration follows the order of water, fish, and sediment. It has been shown that crops irrigated with tainted water contain dangerous metals. The analysis of daily intake data on carcinogenic and noncarcinogenic substances reveals that consuming contaminated food can seriously impact human health.
Mostrar más [+] Menos [-]Environmental Flow Assessment (EFA) of Tawi River Discharge at the Jammu Location Using the Global Environmental Flow Calculator (GEFC) Texto completo
2023
Maharshi Yadav, Govind Pandey and Pradeep Kumar
The water, food, and energy demands are the basic requirements of society. These demands are increasing daily due to an increase in population or lifestyle changes. To fulfill these ever-increasing demands, several water resource projects have come up which require the storage or diversion of river water. These interventions have caused widespread degradation of aquatic ecosystems. Due to the degradation of the aquatic ecosystem, several programs all around the globe began. In this series, Brisbane Declaration (2007) provided a more holistic definition of Environmental Flows (EFs) as the quantity, timing, duration, frequency, and quality of flows required to sustain freshwater, estuarine and near-shore ecosystems and the human livelihoods and well-being that depend on them. The present study was envisaged to assess for environmental flows of the Tawi river with a major objective of assessing the environmental flows of the Tawi river using the Global Environmental Flow Calculator developed by IWMI. The method provides E-Flows for different Environmental Management Classes. For the western Himalayan region, the river stretches in Environmental Management Class ‘B’ and ‘C’. The assessment provides E-Flows in two ways: (i) the percentage of Mean Annual Runoff and (ii) average monthly environmental flows. E-Flows were estimated as 42.34% to 56.96% of Mean Annual Runoff and varied from 5.73 cumecs during November to 68.23 during August.
Mostrar más [+] Menos [-]Visitors Perceptions of the Climate Comfort at the Padang Coastal Tourism Area, Indonesia Texto completo
2023
N. Y. Sudiar and M. I. Gautama
This study explains visitors’ perceptions of climate comfort in the Padang coastal tourism area, including Air Manis Beach, Padang Beach, Nirwana Beach, and Pasir Jambak Beach. Climate comfort index calculation using the Holiday Climate Index (HCI) and survey methods are used to take data. The survey is conducted to collect data on climate comfort perception and the role of weather on that comfort. There are 409 respondents in this study. Most visitors state that weather affects climate comfort during their trip (99%) and need weather information for outdoor tourism (98.5%). However, only 27.1% are looking for weather information before traveling outdoors. This coastal tourism area’s perceived level of climate comfort is comfortable (64%). The thermal sensation is neutral (66%). Meanwhile, the average score of the comfort index in Padang is neutral throughout the year. The temperature interval indicates the comfortable category is between 26ºC-28ºC.
Mostrar más [+] Menos [-]Comparative Assessment and Monitoring Changes in NDVI of Achanakmar Tiger Reserve (ATR) and its Buffer Zone, India Texto completo
2023
Anupama Mahato
Achanakmar Tiger Reserve (ATR), endowed with rich biological diversity and lush green vegetation in and around, makes it more unique. It is also an integral part of the Achanakmar Amarkantak Biosphere Reserve (AABR) and has been identified as one of the important tiger reserves of the Central Indian landscape due to its connectivity with other protected areas and tiger reserves in neighboring landscapes. Vegetation mapping and monitoring are important to understand changes in ecosystem processes and associated temporal and spatial impacts. Pre- and post-monsoon IRS, LISS III, and AWiFS satellite data from 2000, 2004, 2008, 2010, and 2013 were used for the present study. This paper is an attempt to examine the variation in the normalized difference vegetation index (NDVI) of ATR and its buffer zone on a seasonal and temporal basis. Climate conditions such as temperature, precipitation, relative humidity, etc. play an important role in the growth and development of healthy vegetation. The NDVI value of ATR has shown fluctuation and recorded positive growth over the past 14 years with few exceptions. The post-monsoon season recorded a higher NDVI value as compared to the pre-monsoon months. The maximum NDVI value was recorded in 2004 (+0.539) for the entire ATR and its buffer zone.
Mostrar más [+] Menos [-]Flood Mitigation and Pollution Abatement in Kaduna Metropolis Through Engineering Assessment and Analytical Hierarchy Process Design Texto completo
2023
O. J. Oyebode and F. Paul
Pollution abatement and flood control activities require effective water resource planning, engineering assessment, sophisticated technology, and appropriate hydraulic structure designs. This paper x-rays flood mitigation and pollution abatement strategies that can be adopted in the Kaduna metropolis in Nigeria. Analytical hierarchy process of design, questionnaires, engineering assessment approach, and standard method for estimation of the runoff discharge was adopted for this research. Estimating water balance components and QSWAT Hydrological Model can be used with the QGIS interface for a greener environment. Suitable hydraulic systems were designed for long-term flood control in the River Kaduna catchment area through an analytic hierarchy Process. Statistical analysis, manning equations, and rational methods were utilized for adequate assessment and planning. The hydraulic discharge capacity of culverts, open channels, and other hydraulic structures was carefully checked. Flooding greatly impacts infrastructural development, and inadequate drainage systems contribute to it. Mitigation strategies, adequate water resource planning, and management will greatly benefit from addressing flood-related issues in the study area. This research provides information on the flood vulnerability of infrastructures and mitigation strategies that can be adopted in the study area. Viable policies and management strategies can be utilized to avert losses traceable to floods in developing and developed countries.
Mostrar más [+] Menos [-]Extreme Flood Calibration and Simulation Using a 2D Hydrodynamic Model Under a Multipurpose Reservoir Texto completo
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.
Mostrar más [+] Menos [-]Protection of the Environment Under Trade and Investment Agreements: An Analysis Based on Existing Legal Frameworks Texto completo
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.
Mostrar más [+] Menos [-]Anaerobic Biodegradability Potential of RCF-Based Kraft Paper Mill Effluent Texto completo
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%.
Mostrar más [+] Menos [-]Isolation and Screening of Probiotic Bacteria from the Gut of Polychaetes as a Probiotic Potential for Fish Aquaculture Texto completo
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.
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