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Wastewater Treatment using Oxidation Ditch Microalgae Chlorella sp.: Insight into the Effect of Intermittent Aeration and Characteristic of Effluent Organic Matter
2024
Cahyonugroho, Okik | Hidayah, Euis | Rahma, Emira
Wastewater treatment with microalgae such as oxidation ditch algae reactor (ODAR) could reduce organic matter, however, the process might produce by-products that are toxic when dissolved in water. Effluent organic matter and algae organic matter are by-products of the microalgae process, that are released as well in ODAR system.The presence of these compounds in water can be a precursor for the formation of disinfection by-products (DBPs). The aim of this study is to determine the characteristics of effluent organic matter contained in domestic ODAR using the microalgae Chlorella sp. under variations of oxic and oxic-anoxic conditions. Microalgae were applied in ODAR under oxic for 24 hours of aeration and oxic-anoxic through a brush aerator on for 7 hours and off for 3 hours with a ratio of waste volume to microalgae 1:1 with sampling time up to 5 hours. The results showed that BOD concentration tends to decrease up to 45% and 67% for oxic-anoxic and oxic, respectively. The UV254 value increased up to 110% and 147% for oxic-anoxic and oxic, respectively. Further, fluorescence excitation-emission matrix (FEEM) analysis identified the changing of four organic fractions as measured by the fluorescence regional index (FRI). The results indicate a decrease of aromatic protein-like significantly up to 62% and a decrease in soluble microbial products up to 30%. While humic acid-like and fulvic acid-like tends to increase by about 25-29% and 44-46%.
Mostrar más [+] Menos [-]Trace metal exposure and health concerns in Bangladeshi rivers: a seasonal comparison of the Buriganga, Shitalakhya, Meghna, Karnaphuli, and Padma rivers' water, sediment, and fish
2024
Hasan, Nahid Bin | Fahad, Md. Abu | Zahid, Abdullah-Al | Hasan, Mahadi | Rahaman, Ashiqur | Hossain, Sakhawat | Sarker, Tama Rani | Hossain, Mohammad Nazmul | Khatun, Nazma
We determined the levels of nine heavy elements in water, sediment, and the edible tissues of three frequently eaten fish species collected from the five polluted rivers in different divisions of Bangladesh. These samples were randomly taken from five rivers and analyzed by Flame Atomic Absorption Spectroscopy. We found seasonal fluctuations in the hierarchy of mean concentration for different heavy metals in five rivers’ fish, water, and sediments. In the water, the concentrations of Cd, Cr, Cu, Fe, Mn, Pb, Zn, Ni, and Hg ranged from 0.010-0.081, 0.016-5.531, 0.013-2.445, 0.860-22.924, 0.043-1.424, 0.015-0.933, 0.091-1.451, 0.012-2.888, and 0.010-0.032 mg/l where in the sediment the concentrations ranged from 0.1-1.47, 4.21-284.1, 0.12-28.46, 1860-14971.33, 122.1-480.8, 0.84-42.15, 2.14-210.35, 15.3-30.4, and 0.17-10.44 mg/kg. For fishes concentrations ranging from BDL-0.78, 0.04-86.45, 0.01-1.67, 4.19-102, 0.08-0.94, 0.01-0.99, 0.08-9.56, 0.01-4.56, and BDL-0.2 mg/kg were reported for the above metals order respectively. The highest concentration (mean) of Cr and Fe in waters and sediments was 1023 times and 13020.72 % higher than WHO’s standard and Toxicity Reference Values (TRV), respectively. Besides, the bioaccumulation factors (BAF) of the selected elements for the studied fishes were found to be between 0.036-626.25, where the pollution load index (PLI) for the five rivers ranged from 0-0.95 and the concentration factor (CF) found between 0.02-4.03. Estimated daily Intake (EDI) as well as Target hazard quotients (THQs) analyses revealed potential risks for fish consumers, particularly the level of some metals exceeding the WHO/FAO's tolerable limit, which indicates that the rivers' water and fish are dangerous to humankind.
Mostrar más [+] Menos [-]Mercuric oxide nanoparticles deferred germination and devastated root anatomy of maize
2024
Hassan, Yasser | AbdElgawad, Hamada | Zaki, Ayman | Hammouda, Ola | Khodary, Salah-Eldin
Given the widespread use of mercuric oxide NPs (HgO-NPs), they have become increasingly prevalent in the soil ecosystem. Consequently, it is important to promptly evaluate their phytotoxic impacts. To this end, we have investigated the effects of HgO-NPs (0-200 mg/L) on germination and early growth of maize. Moreover, we have evaluated the interactive influences of HgO-NPs toxicity on the elongation and anatomical structures of primary roots. Relative to control, HgO-NPs decreased the germination percentage, speed and rate, but increased the mean germination time, mean daily germination time and time to 50% germination. The length and biomass of root and shoot and seedling vigour indices have significantly deteriorated. The inhibitory impacts of HgO-NPs on growth parameters were more pronounced in root than in shoot. The response of root was concomitant with dose and time-dependent inhibitions in root elongation and significant drops in root diameter, stele size, cortex size, and cortical cells count. The consequences of HgO-NPs were dose-dependent. For instance, the decrease of maize germination, growth, root elongation, and anatomy were more evident at 200 mg/L HgO-NPs compared to other doses and control. Overall, this study suggests that the presence of HgO-NPs leads to phytotoxic effects on germination and growth of young seedlings, highlighting a noteworthy challenge and environmental concern.
Mostrar más [+] Menos [-]Localized Environmental Pricing of Noise Pollution in Iran
2024
Amini, Fariba | Karbassi, Abdolreza | Amiri, Mohammadjavad
Noise pollution has detrimental negative externalities which Scholars have attempted to evaluate the noise externalities economically, but environmental pricing has not been considerably applied to assess economically noise pollution. The present research aims to quantify the economic cost of noise pollution using the environmental pricing framework proposed by the Delft University. To realize environmental pricing frameworks, this study estimates the costs of noise pollution in the area of Tehran metropolitan. The study attempts to apply the environmental prices framework to local conditions with the assistance of GDP and Gini coefficient. The results demonstrate that the Localized Environmental Prices (LEP) mechanism is capable of internalizing environmental prices. The research indicates that LEP demonstrates the significance of noise pollution necessity to reduction. The results of present investigation show that the sum of environmental prices for noise pollution at Tehran is 56271911 €/year. It also offers a useful foundation for planners and policymakers to make more rational decisions.
Mostrar más [+] Menos [-]Impact of Fertilizer Factory Emissions on Radiological Content of Soil: A Study in Upper Egypt
2024
Fares, Soad
This study investigated the potential impact of a fertilizer factory in Upper Egypt on the surrounding soil's radioactivity levels. Gamma-ray spectrometry was used to measure the concentrations of naturally occurring radionuclides (226Ra, 232Th, and 40K) in soil samples collected near the factory. Additionally, radon gas concentrations were measured, and various radiological hazard indices were calculated. Activity concentrations of 238U, 226Ra, 232Th, and 40K varied in the soil samples, ranging from 110.63 to 326.12 Bq/kg for 238U, 172.72 to 582.37 Bq/kg for 226Ra, 25.63 to 189.15 Bq/kg for 232Th, and 252.20 to 713.24 Bq/kg for 40K. Radium equivalent activity, absorbed gamma dose, and external and internal hazard indices exceeded permissible levels. Radon gas concentrations varied from 20.89 to 192.30 Bq/m3, with an average of 104.43 Bq/m3. The calculated effective dose from radon inhalation exceeded the recommended limit. The elevated levels of radioactivity in soil and the high radon gas concentrations suggest a potential health risk for farmers and residents near the fertilizer factory. Further investigations and mitigation strategies may be necessary to ensure the safety of the surrounding population.
Mostrar más [+] Menos [-]The geochemistry of strontium-90 in peatlands of the European Subarctic of Russia
2024
Lukoshkova, Anna | Yakovlev, Evgeny | Orlov, Alexander
The subject of this research is the vertical migration of strontium-90 in peatlands of the European Subarctic region of Russia. The activity level of strontium-90 has been determined in peat samples, and the physicochemical parameters of peat deposits have been studied. The specific activity of the radionuclide has been determined using beta radiometric methods with radiochemical preparation according to the methodology. The physicochemical parameters of the peat have been determined using weight-based methods according to the specified procedures. The influence of physicochemical parameters on the vertical migration of the radionuclide in peatlands has been evaluated using correlation analysis. The results have shown that the specific activity of strontium-90 in peat deposits ranges from 0.25 to 7.7 Bq/kg. The results are consistent with typical values for all soils in Russia. The average value of the specific activity of strontium-90 in peat deposits is estimated to be 1.5±0.02 Bq/kg, which is below the established minimum values and average parameters for all soils in Russia. The pathways of vertical migration of strontium-90 in peat deposits demonstrate a downward direction with various trajectories. These pathways serve as a trace of past global atmospheric radioactive fallout. The vertical migration of strontium-90 in peat is associated with the organic matter content, ash content in peatlands, and recent local atmospheric fallout from nuclear fuel facilities. The research results provide valuable information for predicting the migration of strontium-90 into aquifers under changing environmental conditions due to the Arctic's rapid climate warming.
Mostrar más [+] Menos [-]Removal of Benzyl butyl phthalate by Polyetheretherketone/polyvinylalcohol nanocomposite Modified with Zinc oxide nanoparticles Adsorbent from Wastewater
2024
Cheraghi, Reza | Abrishamkar, Maryam | Jalali Jahromi, Hossein | Hoseini, Farzaneh
The applicability of Polyetheretherketone/polyvinylalcohol nanocomposite modified with zinc oxide nanoparticles synthesis for the removal of benzyl butyl phthalate from wastewater. Identical techniques, including BET, FT-IR, XRD, and SEM, have to characterize this unknown material. The investigation shows the applicability of adsorbent PEEK/PVA/ZnONPs, as an available, suitable, and low-cost adsorbent for adequately removing the benzyl butyl phthalate from wastewater. The impacts of variables, including benzyl butyl phthalate concentration, adsorbent, pH, and time (15 mgL-1, 0.3 g, 5.0, and 60 min). Based on the received data, the adsorption of benzyl butyl phthalate on the PEEK/PVA/ZnONPs adsorbent agrees well with the Langmuir adsorption model isotherm (qm = 34.24 mgg-1). The results of the thermodynamic parameter showed a negative enthalpy (-77.0 KJ/mol), a negative Gibbs free energy (-11.7 KJ/mol), and negative entropy (-274.0 J/K.mol). This led to the conclusion that the adsorption process is energetically possible, and exothermic was also spontaneous. This work indicates that the PEEK/PVA/ZnONPs, used as an ecologically adapted, adsorbent holds promise for eliminating benzyl butyl phthalate from wastewater.
Mostrar más [+] Menos [-]A framework of Trapezoidal Fuzzy Best-Worst Method in Location Selection for Surface Water Treatment Plant
2024
Debnath, Kalyani | Debnath, Piyali | Choudhury, Sudipa | Saha, Apu | Majumdar, Abhijit
Decision-making under uncertainty refers to a dilemma when a decision-maker is aware of a variety of potential natural states but lacks adequate information to assign any probabilities of occurrence to them. The uncertainty related to the input parameters is one of the main issues in the majority of decision-making situations. Uncertainty may produce some irrational results, which could make the decision-making process even more challenging. To overcome this challenge, a fuzzy extension of Best-Worst Method (BWM) has been proposed, using trapezoidal fuzzy sets, to combine the advantages of a reduced number of pair-wise comparisons and easy handling of ambiguity. The criteria and alternatives have been evaluated by the proposed Trapezoidal Fuzzy Best-Worst Method (TrFBWM), where the weight of each element is represented by a Trapezoidal Fuzzy Number (TrFN). To verify the coherence of judgment, the consistency ratio is evaluated for TrFBWM. The proposed method is then applied to the location selection of a water treatment plant along the bank of the Brahmaputra river in Assam. The obtained results are compared to one previous work and found that the outcomes of the proposed method indicate a good agreement with that. The outcomes of the study provide useful insights for selecting a suitable location for a surface water treatment plant which can also be extended to other service facilities.
Mostrar más [+] Menos [-]Preliminary Study of Reduction of Microplastics Contained in Salt Produced in Padang, Indonesia
2024
Deswati, Deswati | Zein, Rahmiana | Bunda, Intan | Putra, Adewirli | Suparno, Suparno
Salt produced from seawater evaporation contains harmful microplastics (MP). For this reason, a technology that can remove MP from seawater using coagulation and filtration techniques is needed. The purpose of this study is to utilize alum as a coagulant and sand as a filtration media to reduce MP pollution in seawater as a source of raw material for salt making. Seawater from Buo Bay, Padang City, Indonesia was taken as raw material for salt production. The MP abundance of salt made from seawater without alum and sand treatment was found to be 400 particles/kg. To reduce the abundance of MP in the salt, we varied the alum concentration (0.1; 0.3; and 0.5 g/L) and sand particle size (≥2, ≥1-<2, and <1 mm). From the results obtained, the optimal condition is an alum concentration of 0.5 g/L and sand particle size is <1 mm. The optimal condition of salt made from seawater in treatment H obtained MP abundance from 400 particles/kg to 30 particles/kg with an MP reduction efficiency of 92.5%. Visual analysis using optical trinocular microscopy found 4 forms of MP, namely: fragments (51.13%), fibers (28.95%), films (15.41%), and pellets (4.05%). Rewith the most dominant MP size found was >100-300 µm. The results of ATR-FTIR analysis identified the types of MP as Polyethylene (14.28%), Polyethylene Terephthalate (42.85%), Polypropylene (14.28%), and Polyamide (28.57%).
Mostrar más [+] Menos [-]3D Voxelisation for Enhanced Environmental Modelling Applications
2024
Ridzuan, Nurfairunnajiha | Wickramathilaka, Nevil | Ujang, Uznir | Azri, Suhaibah
Monitoring and managing environmental problems, particularly those impacting human health such as noise and air pollution, are essential. However, the current implementation has certain limitations that need improvement. In the case of noise pollution, accurately computing noise levels requires considering traffic noise propagating in all directions, necessitating the involvement of a 3D building model. Existing methods using raster cells and noise contours are insufficient in achieving high accuracy. To overcome this, we propose integrating a voxelisation approach and 3D kriging, enabling the depiction of traffic noise values for each voxel. In the context of air pollution, wind movement plays a significant role in the dispersion of contaminants. The current practice involves a random selection procedure for wind simulation within the model discretisation. However, we suggest replacing this randomness with a voxel-based model, which not only improves accuracy but also reduces computing time. Thus, the voxel-based model represents the building model in a wind computation environment, facilitating more realistic wind simulation results. This study demonstrates the applicability of the voxelisation technique in two different environmental modeling contexts using the building model of the city building modeling standard. The level of detail (LoD) in the represented building model differs between these approaches. For traffic noise, a low LoD (LoD1) is sufficient to depict exterior buildings accurately. However, for wind simulation, a higher LoD (LoD2) is necessary to accommodate the complexity of buildings and determine appropriate voxel sizes. In conclusion, the proposed improvements in the form of voxel-based modeling techniques offer enhanced accuracy and efficiency in environmental monitoring. The findings of this study have implications for improving the management and reduction of environmental problems, ultimately benefiting human health and well-being.
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