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Geotechnical Investigation of Tailings Disposal Site for Tailings Storage of zinc Processing Factory 全文
2022
Shirdam, Ravanbakhsh
The present study aims at determining the geotechnical properties of the tailings and the natural bed at Iran Mineral Processing Company, Sites 1 and 5. It qualitatively studies the subsurface layers of the company’s tailings storage site. After drilling different boreholes and conducting in-situ tests, it has made laboratory analyses in the form of field exploration to determine the geotechnical parameters of the extracted samples. Results from the analyses show the permeability coefficient of the subsurface layer of Site No. 1 and 5 to be very small, in the range of 10-7 cm/sec. Considering the conformity of permeability coefficient, percentage of fine grains (98% to 99%), plasticity index (28.5-29.5), and clay content of different layers of Sites 1 and 5 (68%-80%), based on the compacted clay liner criteria, it can be concluded that by nature, the subsurface layers of the mentioned sites are sealed with no need for any compacted clay liner. The tailings for storage Site 5 are fine-grained (80-88<75mm), basically in ML range according to USCS system, with a permeability coefficient of about 10-6 cm/sec. Therefore, the tailings themselves act as a relatively primary sealing layer against the infiltration of hazardous leachates into the natural bed. The method, used in the process of site selection of tailings storage facilities (TSF), can cut the construction time as well as the expenditures, thus reducing the production costs in the long run.
显示更多 [+] 显示较少 [-]Radiological Hazards Associated with 238U, 232Th, and 40K in some selected Packaged Drinking Water in Ilorin and Ogbomoso, Nigeria 全文
2022
Ajibola, Taiye Benjamine | Orosun, Muyiwa Michael | Ehinlafa, Olusegun Emmanuel | Sharafudeen, Fatimah Anike | Salawu, Banji Naheem | Ige, Simon Olatunji | Akoshile, Clement O.
In order to ensure radiation monitoring and protection, investigation and assessment of radiological risks that may be associated with the consumption of packaged table waters commonly consumed in Ogbomoso and Ilorin metropolis, Nigeria, was carried out. The measurements were carried out using a ‘3 x 3’ inch lead-shielded NaI (Tl) detector coupled through coaxial cable to a multichannel analyser. The measured activity concentrations of the natural radionuclides in the packaged drinking water sample are mostly within the recommended limits. The estimated mean Annual Effective Dose was found to be within the acceptable limits of 1 mSv/y for the general populace except for the infants which is slightly higher for some of the samples. The estimated Excess Lifetime Cancer Risk were found to be lower than the world average value of 0.2 x 10-3 in only two of the selected packaged drinking water. This implies the possibility of developing cancer over a lifetime considering seventy years as the average life span is considerably high.
显示更多 [+] 显示较少 [-]Proposal for a High-Resolution Particulate Matter (PM10 and PM2.5) Capture System, Comparable with Hybrid System-Based Internet of Things: Case of Quarries in the Western Rif, Morocco 全文
2022
Ghizlane, Fattah | Mabrouki, Jamal | Ghrissi, Fouzia | Azrour, Mourade
Atmospheric models today represent all significant aerosol components. Atmospheric aerosols play an important role in the air, globally through their action on the Earth's radiation balance and locally through their effects on health in heavily polluted areas, they vary considerably in their properties that affect the way they absorb and disperse radiation, and they can thus have a cooling or warming effect, they impact on the formation and life of clouds is one example. Among the main sectors of activity releasing emissions of PM10 (fine particles with a diameter of less than 10 µm) and a diameter of less than 2.5 µm (PM2.5) is the industrial sector, in particular the extraction industry of building materials. The aerosols emitted by this type of industry are composed mainly of a mixture of dust, sulphates, carbon black and nitrates, is clearly perceptible in many continental regions of the northern hemisphere. Improvements in in situ, satellite and surface measurements are needed. However, the mechanisms by which aerosols interact with the environment are extremely complex and still poorly understood. This study is based on satellite atmospheric models to have spatiotemporal variability of concentrations of fine particles smaller than 10 µm in diameter (PM10) and smaller than 2.5 µm in diameter (PM2.5) at the level of the western Rif part of Morocco, home to a large number of extraction quarries and thus offering a high-resolution particle capture system (PM10 and PM2.5).
显示更多 [+] 显示较少 [-]Atmospheric Aerosol Loading and Properties over India: A review 全文
2022
Mor, Vikram | Dhankhar, Rajesh
Atmospheric aerosols are very crucial from air pollution and health perspective as well as for regional and global climate. This paper attempts to summarize the aerosol loading and their properties such as Aerosol Optical Depth (AOD), Single Scattering Albedo (SSA), Angstrom exponent, and Radiative forcing, over India. All the above mentioned parameters have shown significant variability with change in the site and season. From various studies it was observed that AOD is relatively higher over Northern part of India as compared to Southern and Eastern part. Generally, lower values of SSA were observed over all sites during winter and post-monsoon seasons which indicates the dominance of absorbing type aerosol during these seasons. Also the ARF within atmosphere showed comparatively higher values during November-December and lower value during August and September all over the India. The current state of knowledge about aerosol sources, interactions and their effects on environment is limited because of its complexity. Therefore, more focused research in needed to understand the aerosol’s role in climatic phenomenon.
显示更多 [+] 显示较少 [-]A Preliminary Study on Mercury Contamination in Artisanal and Small-Scale Gold Mining Area in Mandalay Region, Myanmar by using Plant Samples 全文
2022
Kuang, Xiaoxu | Kyaw, Win Thiri | Soe, Pyae Sone | Thandar, Aye Myat | Khin, Hnin Ei | Zaw, Nan Myat Pyae | Sakakibara, Masayuki
A large anthropogenic source of mercury pollution is mercury-dependent artisanal and small-scale gold mining (ASGM). Thabeikkyin Township is a small-scale gold mining township located in Pyin Oo Lwin District in the Mandalay Region, Myanmar. The villages of Thabeikkyin Township engage in gold ore crushing, screening, refining, and other mining activities for a living. Miners in this area commonly use mercury for gold recovery by heating amalgam at their homes, gold shops, on the street, and near the riverbank. The evaporated mercury is released into the atmosphere during the heating process and then transported and deposited in the surrounding environments, resulting in the mercury pollution of air, water, soil, etc. To assess atmospheric mercury pollution, a preliminary study on the environmental mercury contamination from ASGM was conducted in Thabeikkyin Township. High mercury concentrations were observed in plant samples collected near the refining sites, ranging 0.33–6.51 ug/g, compared with 0.02 ug/g in Wet Thay Village, where no mercury use was reported. Correlation coefficients between Hg and other heavy metals showed that no heavy metal concentration significantly correlated with that of Hg. The results indicated that the atmospheric environment in the ASGM area of Thabeikkyin Township was contaminated with mercury originating from ASGM, which could very likely deteriorate the health of surrounding residents.
显示更多 [+] 显示较少 [-]Constructed Wetlands: A sustainable way of Treating Wastewater in Cold Climate - A review 全文
2022
Singh, Adarsh | Katoch, Surjit | Bajpai, Mukul | Rawat, Akash
The use of constructed wetland (CW) is a natural way of treating wastewater sustainably and economically. However, the implementation of these systems in freezing conditions is still a matter of research and development. The treatment capacity of CWs relies largely on the biological and biochemical processes which further depends on physical conditions such as temperature, solar radiations, etc. Application of wetland systems for treating wastewater faces many challenges in regions with cold climates, resolving which this review has been made. This paper presents a thorough understanding of the components of CWs and their role in contaminant removal. A comprehensive review of the different types of CWs has been done describing the treatment efficiency achieved by its implementation in the cold climate. Furthermore, various technologies which can be clubbed with CWs have also been listed along with the treatment efficiencies obtained. Literature survey indicates that the extent of removing organics (COD and BOD5) and total phosphorous (TP) are not likely to be affected, but total nitrogen (TN) removal appears to slow down at low temperatures. Despite several advantages of CW technology, further research is required to select suitable macrophytes and optimum design parameters to compensate for frigid conditions.
显示更多 [+] 显示较少 [-]Ozonation of Procion Blue Reactive Dye and its Kinetics Study 全文
2022
Bhad, Rahul M | Das, Arijit | Kodape, Shyam M.
In advanced oxidation processes, the application of ozonation has been immensely used in recent years for the treatment of effluent water from pharmaceutical, textile and chemical industries. In this study, procian blue, a major and vastly used reactive dye in the textile industry was chosen for ozonation. This work investigated the effect of ozonation for the treatment of synthetic textile effluent water. The change of pH values of dye solutions from 2-12 had moderate effect on dye removal. The degradation rate was faster during the initial period of ozonation and reached highest dye removal around 90 minutes. The highest 87% removal of dye was observed for the case of 60 mg/L dye solution at pH 12. At higher pH, the dye degradation increased as the rate of formation of hydroxyl radical increased with pH. Factors influencing on dye degradation like concentration of dye, time of ozonation, and addition of H2O2 with ozone (combined treatment) were also evaluated. The combined treatment (5 g/L of hydrogen peroxide) increased the degradation of dye to 92% as compared to 85% for pure ozonation process of 60 mg/L dye solution of initial pH 10. The procian blue dye degradation followed pseudo-first order kinetics with a value of rate constant 2.48×10-2 /min.
显示更多 [+] 显示较少 [-]Waste Orange Peel Adsorbent for Heavy Metal Removal from Water 全文
2022
Yirga, Awash | Yadav, Om Prakash | Dey, Tania
Batch adsorption process was employed to remove copper(II) and cadmium(II) ions from contaminated water using dried orange peel powder as a cellulosic adsorbent, which supports circular economy and sustainability. Metal ion concentrations were determined using a flame atomic absorption spectroscopy (FAAS). Effects of pH, sorbate-sorbent contact time, metal ion concentration and adsorbent dose on the removal efficiency of the metal ions was investigated. The adsorption equilibrium was reached at 120 and 150 minutes for Cu(II) ions and Cd(II) ions, respectively. At optimized pH and biosorbent load, 10 mg L-1 of Cu(II) and Cd(II) ions could be removed to the extent 96.9% and 98.1%, respectively, within 2 hrs. However, the percentage removal of metal ions decreased with increasing their initial concentrations. The observed adsorption data was also interpreted in terms of Langmuir and Freundlich adsorption isotherm models. The calculated equilibrium data fitted more adequately with Freundlich model (higher correlation coefficient, R2) than Langmuir model, indicating heterogeneity of adsorption sites due to different functional groups in cellulose. Cd(II) ions showed less binding affinity and less desorption than Cu(II) ions. The maximum adsorption capacity (qmax) of dried orange peel were 2.78 mg/g and 2.57 mg/g for copper(II) and cadmium(II) ions, respectively.
显示更多 [+] 显示较少 [-]Estimation of possible Biodegradation of Polythene by Fungal Isolates Growing on Polythene Debris 全文
2022
Saxena, Ankita | Jain, Sapna | Pareek, Arvind
Consumption of polythene is unavoidable in this era and it is increasing day by day. Polythene’s hazardous waste is adversely effecting environment. In fact any form of polythene is a nuisance to the environment because of strong resistance against degradation thus; they remain in nature for a very long time. Biodegradation is the only promising solution to overcome this problem. Fungi, a group of saprophytic organisms are evolved to adapt for almost every environment, specially marine and freshwater source. This property drives fungi to grown on polythene even in adverse environment. So, present study was planned to compare biological degradation of low density polythene [LDPE] and biodegradable polythene by potential fungus to find out an eco-friendly and economic solution of polythene waste. Ten fungal strains were isolated from rotting polythene debris those are Penicillium chrysogenum, Rhizopus nigricans, Chaetomium murorum, Memnoniella echinata, Aspergillus fumigatus, Stachybotrys chartarum, Aspergillus niger, Chaetomium globosum, Aspergillus flavus and Fusarium oxysporum, in which Penicillium chrysogenum, Rhizopus nigricans, Aspergillus fumigatus, Aspergillus niger and Aspergillus flavus showed greatest results in terms of degrading both Low density polythene and biodegradable polythene. These isolates also showed good enzymatic reaction and weight loss. SEM analysis of polythene surface was also in support of these findings.
显示更多 [+] 显示较少 [-]Health Risks of Ecosystem Services in Ologe Lagoon, Lagos, Southwest Nigeria 全文
2022
Yahaya, Tajudeen | Muhammad, Alkali | Onyeziri, Joy Ada | Abdulazeez, Abdulmalik | Shemshere, Ufuoma | Bakare, Tayo | Yusha’u, Bello Kalgo
Ologe Lagoon is one of Lagos, Nigeria’s five major lagoons, which provide essential ecosystem services such as agriculture, fishing, transportation, salt and sand mining, tourism, and industrial development. There are concerns, however, that the lagoon’s water may not be safe for the ecosystem functions it offers. As a result, the physicochemical properties, heavy metal concentrations, and microbial loads of water samples from the lagoon, as well as their health risks, were examined in this study. Physicochemical analysis showed that calcium, chloride, nitrates, sulphate, dissolved oxygen, acidity, alkalinity, total dissolved solid, and total suspended solid were present within the World Health Organization permissible limits, but not so for phosphate and temperature. The heavy metal analysis revealed that the water had non-permissible levels of iron, cadmium, chromium, nickel, manganese, and copper, but lead was normal. The microbiological examination showed abnormal bacteria counts, while coliform and fungus were not detected. The average daily oral and dermal exposure to cadmium, chromium, and nickel were higher than the recommended daily intake, but iron, lead, and copper were within the limits. The hazard quotient of oral and dermal exposure to cadmium, dermal exposure to chromium, and oral exposure to manganese were higher than the recommended limit (> 1). The carcinogenic risks of Cd, Cr, and Ni were also greater than the acceptable limit. The results obtained indicate that Ologe Lagoon’s water is unsafe for the lagoon’s ecosystem functions. Relevant agencies should ensure that waste is treated before being discharged into the lagoon.
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