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The Effect of COVID-19 on the Atmospheric Parameters Over the Indian Subcontinent Texte intégral
2021
C. Ramprasad
In the present study, the atmospheric concentrations of various pollutants over the Indian subcontinent before the COVID-19 (during 2019) and during COVID-19 phases (2020) were studied. The COVID-19 has created a negative impact on the country’s economy but has positivity over the atmospheric resources. The levels of carbon monoxide (CO), nitrogen dioxide (NO2), and UV aerosol index were assessed using satellite images for the two different phases. The obtained results can be interpreted and can be substantiated with the lockdown effect due to the COVID -19 pandemic. The pollutants are mostly emitted from anthropogenic sources like vehicular emissions, industrial emissions, power plants, construction works, commercial and institutional places. It was evident that the levels of carbon monoxide, nitrous dioxide and aerosols levels have drastically decreased during the lockdown period. Hence, it can be concluded that COVID-19 has cleaned the atmospheric pollution as well as climate change scenario and nature on its own.
Afficher plus [+] Moins [-]Characterization Studies on Adsorption of Lead and Cadmium Using Activated Carbon Prepared from Waste Tyres Texte intégral
2021
H. Joga Rao
The aim of this work was to investigate the utilization of waste tire carbons as a low cost adsorbent for the removal of cadmium and lead ions from an aqueous solution. Surface functional groups would help in getting thorough knowledge about the adsorption capacity of the adsorbent. Thus, activated carbons were prepared from waste rubber tyres and characterized by means of field emission scanning electron microscopy, energy-dispersive X-ray and Fourier transform infrared spectroscopies. The FTIR spectra show that the adsorption peaks are shifted or disappeared and new peaks are formed which was due to the adsorption of lead and cadmium onto the adsorbent surface. It is evident that the characteristic adsorption peak of O-H stretching vibration was shifted from 3900 and 3075 cm-1 for lead and the asymmetrical stretching vibration at 3900 cm-1 was shifted to 3675 cm-1 for cadmium. This shift in peak indicates the interaction between metal ions and –OH groups of adsorbent due to the presence of alcohols, phenols, and carboxylic acid and which shows the decrease of free hydroxyl group content due to the interaction between lead cadmium with –OH groups of the adsorbent. SEM micrograph of adsorbent before adsorption is highly heterogeneous and the surface morphology of the adsorbent is rough. The pores were completely filled with the metal ions after the adsorption of lead and cadmium metals and the pores appear to be smooth. This observation indicates that the metal is adsorbed to the functional groups present inside the pores. From the XRD analysis, the CI index for raw, lead and cadmium loaded activated carbon of waste tyres were found to be 48.91%, 81%, and 54.9% respectively. These values clearly showed the increase in crystalline material present in the adsorbent after the adsorption of metal ions, which was due to the adsorption of metal ions onto the surface of the adsorbent.
Afficher plus [+] Moins [-]Photoelectrocatalytic Oxidation of Textile Industry Wastewater by RuO2/IrO2/TaO2 Coated Titanium Electrodes Texte intégral
2021
R. Rathinam and M. Govindaraj
Photoelectrocatalytic Oxidation (PECO) system prominently increases the migration of photoexcited charges, hinders the fast recombination of electron-hole, and increases the period of photogenerated holes. In this article, we constructed a novel PECO system to degrade textile industry wastewater by RuO2/IrO2/TaO2 coated titanium electrodes. The result shows that PECO treatment can effectively reduce the color and true color of the secondary pollutants present in the wastewater. It is confirmed that a synergistic effect exists between photocatalysis (PC) and electrocatalysis (EC). Moreover, we discussed the influence of pH, current density, electrolyte concentration, and stirring speed. The maximum decolorization efficiency of textile industry wastewater with a pH of 8.2 was found to be 96% under the optimum condition stirrer speed of 200 rpm, an electrolyte concentration of 0.05M, a current density of 15 mA.cm-2, and at a treatment time of 30 mins. The UV-Visible spectra confirm the degradation of textile industry wastewater.
Afficher plus [+] Moins [-]Effect of Heat Treatment Process on the Structure and Properties of Nano-TiO2 Texte intégral
2021
R. Q. Gao, Y. R. Huang, D. Liu and G. T. Li
Nano-TiO2 was prepared with butyl titanate as a precursor by sol-gel method. The samples were analysed by TG-DTA, X-ray diffraction, TEM and so on to assess the effects of different temperatures on the crystal structure, grain size, and microstructure of nano-TiO2. Meanwhile, the catalytic effect of heat treatment temperature on the degradation performance of TiO2 to methyl orange was investigated. The dynamic process of grain growth was preliminarily analysed by Eastman’s particle growth theory. The result shows that TiO2 particle size gradually increases with the heat treatment temperature. At 450 to 550°C, the grain is mainly anatase phase, a mixture of anatase and rutile phase was found at 650°C (mass ratio A:R = 9:1), and the degradation rate of nano-TiO2 on methyl orange reaches 97.75%. When the calcination temperature exceeds 850°C, TiO2 particles almost entirely are composed of rutile phase, and the photocatalytic activity decreases significantly. At 730°C, half of the crystalline TiO2 is transformed from anatase to rutile form. The apparent activation energies of the anatase and rutile crystals of nano-TiO2 are 18.15 kJ/mol and 42.56 kJ/mol, and the fastest grain growth occurs at 546°C and 1280°C respectively.
Afficher plus [+] Moins [-]Effect of Chlorpyrifos 50% + Cypermethrin 5% EC on Eisenia fetida Exposed in Coco Peat and Sphagnum Peat Texte intégral
2021
A. Rajini and K. Revathy
Toxicity effect of Chlorpyrifos 50% + Cypermethrin 5% EC to terrestrial invertebrate Eisenia fetida in two different sphagnum peat substituted soil was assessed. Artificial soil substrate for earthworm toxicity test comprises of 70% sand, 20% clay and 10% sphagnum peat. In this study, coco peat was used as an alternative substitute for sphagnum peat. The LC50 was 83.7 mg/kg for coco peat and 76.3 mg/kg for sphagnum peat soil. No significant difference was observed in mortality and biomass between the two soil substrates, but a significant difference was observed in the reproduction. Based on the observations, it is concluded that coco peat can also be used as an alternative to sphagnum peat in toxicity studies.
Afficher plus [+] Moins [-]Implementation of Eco-Industrial Park for Effectual Establishment of Circular Economy in Russia Texte intégral
2021
Ipsita Saha, Tatiana S. Smirnova and Vladimir A. Maryev
In recent years, waste management has become a major concern in Russian cities. This can be addressed through the circular economy. Developing Eco-Industrial Parks (EIP) can be considered an innovative infrastructure of a circular economy. EIP is based upon the principles of industrial symbiosis involving the exchange of material and energy flows, sharing of infrastructural facilities, and provision of municipal utility and other services. Researchers have found that most industrial symbiotic interconnections originated spontaneously, the main driver being the increasing commercial benefits of such interchange. Still, the authors were able to identify pre-designed EIP through their examination of global practices. This paper proposes a five-stage methodological approach to EIP organization. This methodology was applied to create a model of an EIP in the Voronezh Region, one of the fastest developing regions in Russia. Implementation of this model is intended to help solve a set of environmental, economic, and social problems of a region. The approach to creating EIPs described in this study can be used in other places to improve resource efficiency and reduce waste disposal. Because Russia’s garbage disposal rate currently exceeds 90% per year, this is one of the country’s top sustainable development priorities.
Afficher plus [+] Moins [-]Recognition of Image-Based Plant Leaf Diseases Using Deep Learning Classification Models Texte intégral
2021
Sakshi Takkar, Anuj Kakran, Veerpal Kaur, Manik Rakhra, Manish Sharma, Pargin Bangotra and Neha Verma
Plant diseases are spread by a variety of pests, weeds, and pathogens and may have a devastating effect on agriculture, if not handled in a timely manner. Farmers face umpteen challenges from a proper water supply, untimely rain, storage facilities, and several plant diseases. Crops disease is the primary threat and it causes enormous loss to farmers in terms of production and finance. Identifying the disease from several hectares of agricultural land is a very difficult practice even with the presence of modern technology. Accurate and rapid illness prediction for early illness treatment to crops minimizes economical loss to the individual and further proves to be productive for healthy crops. Many studies use modern deep learning approaches to improve the accuracy and performance of object detection and identification systems. The suggested method notifies farmers of different agricultural illnesses, prompting them to take further essential precautions before the disease spreads to the whole agricultural field. The primary objective of this study is to detect the illnesses as soon as they begin to spread on the leaves of the plants. Super-Resolution Convolutional Neural Network (SRCNN) and Bicubic models are employed in the system to identify healthy and diseased leaves with an accuracy of 99.175 % and 99.156 % respectively.
Afficher plus [+] Moins [-]Biosynthesis of Xanthan Gum by Xanthomonas campestris Using Cane Molasses as a Carbon Source Texte intégral
2021
Bhumi Rajyaguru, Ajit Varma, Amit Kharkwal and Jasvir Singh
The objective of the present study was to study the optimization conditions for the production of xanthan by Xanthomonas campestris from pre-treated sugarcane molasses. In the study, the optimization was carried out for different parameters including pH, temperature, and incubation time for the pre-treated sugarcane molasses. The age of inoculums and time of culture growth (6, 12, 18 and 24 hrs), size of inoculums (2%, 5%, 7.5% and 10%), pH (6.6, 6.8, 7.0 and 7.2) and temperature (25°C, 28°C, 30°C, 32°C and 37°C) were studied. It was observed that the xanthan production was maximal with 7.5% (v/v) inoculums, pH. 7 at 30°C for 48 hrs. The study suggested that cane molasses is an appropriate agro-industrial substrate for xanthan gum fermentations, and further scale-up study is needed for gum production in the stirred fermenter.
Afficher plus [+] Moins [-]Phytochemical Evaluation, FT-IR and GC-MS Analysis of Leaf Extracts of Pergularia daemia Texte intégral
2021
M. Maheshwari and P. Vijayarengan
Pergularia daemia is traditionally used to treat various ailments like anthelmintic, antipyretic and expectorant and to treat infantile diarrhoea, malarial intermittent fever, asthma, mental disorder, toothache and cold. In the present study leaf extracts of P. daemia was subjected to qualitative phytochemicals, GC-MS and FT-IR analysis. The quantitative analysis of the leaves showed the presence of flavonoids, steroids, alkaloids, terpenoids, saponins, phenols, carbohydrates, amino acids, tannins and cardiac glycosides. The GC-MS study of methanol extract revealed 16 compounds. Some major compounds identified are 9-Octadecenoic Acid (E), Cis- Vaccenic Acid, N-Hexadecanoic Acid, 1- Dimethyl (Butyl), Silyl Oxy Butane along with other minor constituents. FT-IR analysis revealed the presence of 12 functional groups such as amines, alkanes, carbon dioxide and alkynes. The results suggested that P. daemia contains significant photo components and can be used as a source for many pharmacological studies and a curative for various ailments.
Afficher plus [+] Moins [-]Review on BOD/COD Ratio Toxicity to Daphnia magna, Artemia salina and Brachydanio rerio Texte intégral
2021
Latifa Mirzatika Al-Rosyid, Harmin Sulistiyaning Titah, Irwan Bagyo Santoso and Sarwoko Mangkoedihardjo
This paper review research works on BOD/COD ratio toxicity to three bioindicators, namely: Daphnia magna, Artemia salina, and Brachydanio rerio. Treatment methods are divided into natural, biological, physical, chemical, combined treatment, and phytotechnology for various types of processing operations such as municipal and industrial wastewater treatment plants, various effluent treatment, landfill leachate, and organic matter. A. salina shows the lowest toxicity value of the BOD/COD ratio and shows it can withstand processing conditions that are not biodegradable. Then followed by B. rerio and D. magna. Furthermore, the disposal limits are standardized for the protection of freshwater biota. In addition, it must be considered whether there is any other potential of disposal into the receiving environment, and if so, what form of disposal and how much, to protect the biota.
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