75 research outputs found

    Removal of Lead from polluted water using waste eggshell

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    In the present project work our plan was to make an attempt to remove heavy metal ions (Pb ions in our case) from polluted water using low cost materials. Eggshell composed of mostly calcium carbonate is a waste natural product available abundantly. Since Ca ions have large affinity towards heavy metal ions, eggshell could be used for said purpose. We prepared artificially Pb-polluted water by adding Pb(NO3)2 in pure water and processed eggshell was used successfully to absorb lead from the solution used as the precursor impurity . Our aim was also to use simple and easily available instruments to detect the absorption of Pb ions from the impure water. The eggshell used was calcined at three different temperatures 3000C, 5000C and 9500C, respectively. The samples were characterized by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), UV-visible spectroscopy and chemical test.The XRD spectra of 5000C and 9500C processed samples after Pb absorption from water indicate the presence of lead in different compositional forms (mostly PbO and PbCO3). The UV-VIS and FTIR spectra were studied to characterize the samples. Finally chemical test was done for confirming the absence of Pb salt in the filtered solution (water)

    Cavitation based wastewater treatment of recalcitrant organic pollutants (Dicofol, BDE-209, HBCD, PFOS, PFOA)

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    Water pollution has been an environmental concern for many years, which have attracted numerous researches for an effective wastewater treatment method to address the issue. Cavitation based wastewater treatments is one of the emerging advanced oxidation processes (AOPs), which has recently drawn attention due to its effectiveness in pollutant removal. But, the effectiveness of cavitational treatment in the elimination of persistent organic pollutants (POPs) is still at an early stage, while considering the wide range of recalcitrant pollutants to be eliminated. Dicofol, Decabromodiphenyl ether (BDE-209), Hexabromocyclododecane (HBCD), perfluorooctanesulfonic acid (PFOS) and Perfluorooctanoic acid (PFOA) are listed or recommended persistent organic pollutants (POPs) under Stockholm convention. For the past several years, numerous reports indicated the detection of above-mentioned POPs in the environmental matrix and hence their elimination via efficient methods is of priority, because of their carcinogenic, endocrine disruptive, hepatotoxic and bioaccumulative nature. POPs are mostly recalcitrant towards conventional treatment methods. Thus, the mineralization of pollutants, treatment duration, energy efficiency etc. are some of the vital concerns to be addressed. The research investigated the sonochemical based method for the removal of Dicofol, BDE-209, HBCD, PFOS and PFOA (PFOX), whereas hydrodynamic cavitation (HC) was implemented for the removal of Dicofol. The effect of various parameters had been studied distinctively by considering sonication power, HC inlet pressure, treatment duration, pH, reaction solution temperature and initial pollutant concentration. The degradation products were monitored by gas chromatography mass spectrometry (GC-MS), liquid chromatography mass spectroscopy (LC-MS), high-performance liquid chromatography (HPLC) and liquid chromatography mass spectroscopy (LC-MS) analysis. GC-MS analysis in selected ion monitoring mode (SIM) and liquid chromatography tandem mass spectrometry (LC–MS/MS) in multiple reaction-monitoring mode (MRM), were performed for accurate monitoring of the concentration of parent compounds. The sonochemical degradation of Dicofol, HBCD, BDE-209, PFOX (PFOS and PFOA) in aqueous media has been investigated using a 20-kHz probe type sonicator with power inputs from 150 to 450 W, whereas the Hydrodynamic cavitation (HC) treatment of Dicofol has been investigated by a liquid whistle reactor (LWR) with an inlet pressure in the range of 3-13 bar. Under optimum conditions of solution pH, reaction temperature, ultrasonic power density and HC inlet pressure, the extent of degradation of Dicofol was found to be 86 % and 100 % within 60 min of ultrasound and HC treatment respectively. Sono-Fenton treatment of BDE-209 demonstrated a complete degradation within 80 min of treatment, whereas sonochemical treatment of PFOX indicated complete disappearance of the parent compounds within 80 min treatment as well. HC treatment of Dicofol illustrated highest mineralization efficiency with 85 % TOC removal within 1 h of treatment. Best mineralization efficiency of sonochemical treatment was achieved for HBCD with 72 % TOC removal within just 40 min of treatment. Overall, cavitation-based wastewater treatments have emerged as potential techniques for the elimination POPs and progressive research is expected to bring out superior treatment efficiency

    Structural Carbohydrates and Lignifications Associated with Submergence Tolerance in Rice (Oryza sativa L.)

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    Role of structural carbohydrate content and lignifications in rice shoot were studied in three indica rice (Oryza sativa L.) cultivars namely FR13A (tolerant to submergence), IR42 (susceptible to submergence) and Sabita (adapted to medium depth, 0-50 cm stagnant flooding), varying degrees of tolerance to submergence under control and 8 days after submergence conditions. During submergence, Sabita and IR 42 accelerated the rate of stem and leaf elongation more than that of FR 13A. Submergence significantly reduces the cellulose and hemicelluloses content. The decrease was more pronounced in susceptible rice cultivar than that of tolerant rice cultivar. Lignifications’ was monitored by measuring the content of lignin and the activities of two enzymes of the lignin biosynthetic pathway, coniferyl alcohol dehydrogenase (CAD) and phenylalanine ammonia-lyase (PAL) in rice shoots. Lignin content and PAL and CAD activity was more in susceptible cv. both under control and 8d after submergence. In conclusion submergence induced elongation of rice shoot might decreased the structural carbohydrate level as our experiment showed a significant negative correlation of cellulose and hemicelluloses with plant height but also positively associated with plant survival under submergence. The content of lignin and activities of CAD and PAL showed negative association with shoot elongation, yet the association of these parameters with survival was non-significant

    Improvement of Photosynthesis by Sub1 QTL in Rice Under Submergence: Probed by Chlorophyll Fluorescence OJIP Transients

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    The influence of submergence on the photosynthetic activity in rice plants either possessing or not possessing Sub1 QTL i.e. Swarna and Swarna Sub1 cultivars (cv.) were evaluated under simulated complete submergence. The leaf photosynthetic rate and stomatal conductance decreased in both the cv. during the progression of submergence as compared to control plant but significant varietal differences was observed after 1 day (d) of submergence. Submergence also alters the photo-system (PS) II activity, as reflected in a decrease in the values of Fo, Fm and the Fv/Fm ratio and degradation of chlorophyll, more in Swarna than that of Swarna Sub1. Under complete submergence the shape of the OJIP transient also changed in rice leaves with decrease in maximal fluorescence (P=Fm) intensity, resulted lowering of variable fluorescence levels. The decrease was more pronounced in Swarna compared to the Swarna Sub1 cv. Thus, Swarna Sub1 improves photosynthetic activity showing more photosynthetic rate compared to Swarna under submergence because, of less degradation of chlorophyll, higher stomatal conductance, and efficient PS II activity

    Diurnal variations in gas exchange and chlorophyll fluorescence in rice leaves: the cause for midday depression in CO2 photosynthetic rate

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    Gas exchange and chlorophyll fluorescence analysis were carried out to investigate the diurnal variations in photosynthesis in leaves of rice (Oryza sativa L.). Leaf CO2 photosynthetic rate (Pn) showed a bimodal diurnal pattern and midday depression in Pn was observed at 13:00 h. Depression in Pn at midday was mostly attributed to stomatal limitation since the reduction in Pn was followed by the significant reduction in stomatal conductance (Gs). Midday depression in Pn was found to be associated with reversible inactivation of Photo-system II (PS II) reaction centers and increase of photo-inhibition in response to high intensity as evidenced by the maximum efficiency of PS II (Fv/Fm) decreased with increase of light intensity from 6:00 h to 16:00 h of a day. The minimal fluorescence (Fo) gradually increased with increasing light intensity and reached its highest value at 13:00 h and on contrary the maximal fluorescence (Fm) decreased and reached its lowest value at 13:00 h. Quantification of several chlorophyll fluorescence parameters (JIP-test) like area above the fluorescence curve between Fo and Fm, phenomenological energy fluxes like electron transport per cross section (ETo/CS), active PS II reaction center per exited cross-section (RC/CSo) and performance index (Pi) were low in early morning, increasing with time and reaching a maximum at 9:00 h subsequently decreasing and reaching a minimum value at 13.00 h. On contrary the dissipation per cross-section (Dio/CS) gradually increased with increasing light intensity and reached its highest value at 13:00 h. It is likely that PS II down-regulation and heat dissipation co-operated together to prevent the chloroplast from photo damage

    Cavitation based wastewater treatment of recalcitrant organic pollutants (Dicofol, BDE-209, HBCD, PFOS, PFOA)

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    Water pollution has been an environmental concern for many years, which have attracted numerous researches for an effective wastewater treatment method to address the issue. Cavitation based wastewater treatments is one of the emerging advanced oxidation processes (AOPs), which has recently drawn attention due to its effectiveness in pollutant removal. But, the effectiveness of cavitational treatment in the elimination of persistent organic pollutants (POPs) is still at an early stage, while considering the wide range of recalcitrant pollutants to be eliminated. Dicofol, Decabromodiphenyl ether (BDE-209), Hexabromocyclododecane (HBCD), perfluorooctanesulfonic acid (PFOS) and Perfluorooctanoic acid (PFOA) are listed or recommended persistent organic pollutants (POPs) under Stockholm convention. For the past several years, numerous reports indicated the detection of above-mentioned POPs in the environmental matrix and hence their elimination via efficient methods is of priority, because of their carcinogenic, endocrine disruptive, hepatotoxic and bioaccumulative nature. POPs are mostly recalcitrant towards conventional treatment methods. Thus, the mineralization of pollutants, treatment duration, energy efficiency etc. are some of the vital concerns to be addressed. The research investigated the sonochemical based method for the removal of Dicofol, BDE-209, HBCD, PFOS and PFOA (PFOX), whereas hydrodynamic cavitation (HC) was implemented for the removal of Dicofol. The effect of various parameters had been studied distinctively by considering sonication power, HC inlet pressure, treatment duration, pH, reaction solution temperature and initial pollutant concentration. The degradation products were monitored by gas chromatography mass spectrometry (GC-MS), liquid chromatography mass spectroscopy (LC-MS), high-performance liquid chromatography (HPLC) and liquid chromatography mass spectroscopy (LC-MS) analysis. GC-MS analysis in selected ion monitoring mode (SIM) and liquid chromatography tandem mass spectrometry (LC–MS/MS) in multiple reaction-monitoring mode (MRM), were performed for accurate monitoring of the concentration of parent compounds. The sonochemical degradation of Dicofol, HBCD, BDE-209, PFOX (PFOS and PFOA) in aqueous media has been investigated using a 20-kHz probe type sonicator with power inputs from 150 to 450 W, whereas the Hydrodynamic cavitation (HC) treatment of Dicofol has been investigated by a liquid whistle reactor (LWR) with an inlet pressure in the range of 3-13 bar. Under optimum conditions of solution pH, reaction temperature, ultrasonic power density and HC inlet pressure, the extent of degradation of Dicofol was found to be 86 % and 100 % within 60 min of ultrasound and HC treatment respectively. Sono-Fenton treatment of BDE-209 demonstrated a complete degradation within 80 min of treatment, whereas sonochemical treatment of PFOX indicated complete disappearance of the parent compounds within 80 min treatment as well. HC treatment of Dicofol illustrated highest mineralization efficiency with 85 % TOC removal within 1 h of treatment. Best mineralization efficiency of sonochemical treatment was achieved for HBCD with 72 % TOC removal within just 40 min of treatment. Overall, cavitation-based wastewater treatments have emerged as potential techniques for the elimination POPs and progressive research is expected to bring out superior treatment efficiency

    Traditional processing associated changes in chemical parameters of wild Yam (Dioscorea) tubers from Koraput, Odisha, India

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    268-276Wild yam tuber considered as famine food and played a prime role in the food habit of tribal people of Koraput district of Odisha, India. The tribal people employed a range of processing of these yams such as boiled, soaked and sun dried for detoxification of antinutrients in accordance with their needs. There is a scarcity of documented information on their nutrient composition/retention by traditional processing methods. The current study assessed the traditional processing (boiled, soaked and sun dried) associated changes in chemical composition and physico-functional characteristics of 6 wild and 1 cultivated Dioscorea tubers collected from Koraput, India. Different processing led to a significant reduction of proximate compositions and nutrient content compared to the raw tuber, whereas physico-functional parameters increased significantly (pDioscorea tubers as safe food sources for mass consumption and should be used in boiling form, as it retains higher nutrients coupled with significant removal of antinutritional compositions

    Traditional processing associated changes in chemical parameters of wild Yam (Dioscorea) tubers from Koraput, Odisha, India

    Get PDF
    Wild yam tuber considered as famine food and played a prime role in the food habit of tribal people of Koraput district of Odisha, India. The tribal people employed a range of processing of these yams such as boiled, soaked and sun dried for detoxification of antinutrients in accordance with their needs. There is a scarcity of documented information on their nutrient composition/retention by traditional processing methods. The current study assessed the traditional processing (boiled, soaked and sun dried) associated changes in chemical composition and physico-functional characteristics of 6 wild and 1 cultivated Dioscorea tubers collected from Koraput, India. Different processing led to a significant reduction of proximate compositions and nutrient content compared to the raw tuber, whereas physico-functional parameters increased significantly (p<0.05). In addition, there was significant decrease in the antinutrients, minerals and vitamin content by different processing in studied yam species. Results suggested that wild Dioscorea tubers as safe food sources for mass consumption and should be used in boiling form, as it retains higher nutrients coupled with significant removal of antinutritional compositions

    Experimental Investigation on Dimensional Characteristics and Surface Morphology of Microchannels Fabricated on Smart Ceramic by DPSS Nd:YAG Laser

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    Smart ceramic material like barium titanate (BaTiO3) is in high demand in today's highly competitive precision industries; as it has numerous applications in electronic, biomedical, and aerospace engineering.In this endeavor, laser micro-milling approach (LMMA) hasbeenattempted with a suitable experimental design plan; to scrutinize the laser influencing variables against the LMMA outcomes during the processing of BaTiO3 throughout the fabrication of microchannels. This article presents an investigational act on the fabricated micro-channels to discern the impacts of LMMA parameters (gas pressure, scan strategy, current and scanning speed) against the dimensional (like deviations in channel upper and lower width) and surface characteristics of the surface feature. The surface morphology study hasbeen accomplished with the support of energy dispersive spectroscopy (EDS) in conjunction with scanning electron microscope (SEM) to scrutinize the elemental alterations and surface characteristics at the zone of laser ablation. A statistical multi-objective optimization (MOO) technique known as grey relational analysis (GRA) has beenused later in this paper to predict an optimal parametric setting. The MOO results’ efficacy has been validated further in the corroboration assessments, the predicted optimal solutions have been obtained with an error of 4.57 %, 3.89 % and 4.88 % for W-RCL, LWD and UWD respectively
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