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| 3. |
- Abbafati, Cristiana, et al.
(författare)
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- 2020
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Tidskriftsartikel (refereegranskat)
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| 4. |
- Chandra, Rajesh, et al.
(författare)
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An approach for dairy wastewater remediation using mixture of microalgae and biodiesel production for sustainable transportation
- 2021
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Ingår i: Journal of Environmental Management. - : Elsevier. - 0301-4797 .- 1095-8630. ; 297
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this work is remediation of dairy wastewater (DWW) for biodiesel feedstock production using poly-microalgae cultures of four microalgae namely Chlorella minutissima (C. minutissima), Scenedesmus abundans (S. abundans), Nostoc muscorum (N. muscorum) and Spirulina sp. The poly-microalgae cultures were prepared as C. minutissima + N. muscorum (CN), C. minutissima + N. muscorum + Spirulina sp. (CNSS) and S. abundans + N. muscorum + Spirulina sp. (SNSS). Poly-microalgae culture CNSS cultivated on 70% DWW achieved 75.16, 61.37, 58.76, 84.48 and 84.58%, removals of biological oxygen demand (BOD), chemical oxygen demand (COD), total nitrogen (TN), total phosphorus (TP), and suspended solids (SS), respectively, at 12:12 h photoperiod that resulted into total biomass and lipid yield of 3.47 ± 0.07 g/L and 496.32± 0.065 mg/L. However, maximum biomass and lipid yields of 5.76 ± 0.06 and 1152.37 ± 0.065 mg/L were achieved by poly-microalgae culture CNSS cultivated on 70% DWW + 10 g/L of glucose at 18:6 h photoperiod. Fatty acid methyl ester (FAME) analysis shown presence of C14:0 (myristic acid) C16:0 (palmitic acid), C16:1 (palmitoleic acid), C18:0 (stearic acid), C18:2 (linoleic acid) and C18:3 (linolenic acid), it indicates that the lipids produced from poly-microalgae cultures are suitable for biodiesel production. Thus, poly-microalgae cultures could be more efficient than mono-microalgae cultures in the remediation of DWW and for biodiesel feedstock production.
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| 5. |
- Krishan, Gopal, et al.
(författare)
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Isotopes (6(18)O,6D and H-3) variations in groundwater with emphasis on salinization in the state of Punjab, India
- 2021
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Ingår i: Science of the Total Environment. - : Elsevier BV. - 0048-9697 .- 1879-1026. ; 789
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Tidskriftsartikel (refereegranskat)abstract
- The state of Punjab has a dominant agrarian economy and is considered India's bread basket. However, it is now under the problem of falling agro-economy primarily because of pervasive depletion of groundwater levels and deteriorating groundwater quality in south-west Punjab, but increasing salinity is a major concern. The irrigation requirements of crops are fulfilled by groundwater and canal water but the introduction of canal irrigation has led to waterlogging and subsequent salinization rendering large fertile-land areas becoming unproductive mainly in the south-western part of Punjab. There was an apprehension that excessive withdrawal of groundwater might have caused a reversal of natural groundwater flow pattern that might have caused ingress of saline water into fresh groundwater region of central Punjab. To address the apprehension related to the rise in groundwater salinity and its subsequent ingression in the fresh-water zone and suggest suitable management solutions, a study was undertaken to analyse the data related to salinity, isotopes, land-use and land cover (LULC) along with field and laboratory experimental results. The depth-wise isotope analysis shows that there is a large variation in isotopic signatures of shallow and intermediate aquifers and it decreases with the depth of aquifers (150-250 m). It appears that very deep groundwater (>250 m) is relatively isolated and does not show a large variation or mixing effect. Tritium analysis shows that dynamic groundwater is actively recharged through canal, river, and/or rain. The presence of modern groundwater at deeper depth indicates a good interconnection between shallow and deep groundwater. Interpretations of the results show that the canal is the main source of groundwater recharge in south-west Punjab and the evaporation process is responsible for increasing the salinity hazard. In the central parts of Punjab, groundwater and rain are the main sources of groundwater recharge, while rain is the main source of groundwater recharge in the Kandi area. In the south-west Punjab, some primary salinity has formed as a result of mineral dissolution which has further increased due to evaporative enrichment.
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| 6. |
- Krishan, Gopal, et al.
(författare)
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Occurrences of potentially toxic trace metals in groundwater of the state of Punjab in northern India
- 2021
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Ingår i: GROUNDWATER FOR SUSTAINABLE DEVELOPMENT. - : Elsevier BV. - 2352-801X. ; 15
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Tidskriftsartikel (refereegranskat)abstract
- In present study, a total of 275 representative water samples (263 groundwater, 8 canal water, 2 samples from Sutlej River and 2 samples from Buddha Nala) were collected and analysed. The sampling was carried out in the month of August, September, and October of 2019. These samples were analysed for the Arsenic (As-total), Aluminium (Al), Iron (Fe), Manganese (Mn), Zinc (Zn), Copper (Cu), Chromium (Cr), Cadmium (Cd), Nickel (Ni), and Lead (Pb). The result found that 3.8 % of the analysed groundwater samples have As concentrations above acceptable limit (10 mu g/L) and similar to 0.38 % samples exceeded the permissible limit of 50 mu g/L. Iron concentration exceeded the acceptable limit of 0.3 mg/L for drinking water in similar to 14.83 % groundwater samples. The mean concentration of iron was found 252 mu g/L and 3810 mu g/L for groundwater and canal water, respectively. It was observed that some samples have concentrations more than acceptable limits in the cities of Ludhiana, SBS Nagar, Rupnagar, SAS Nagar districts and in parts of Mansa, Amristar and Gurdaspur districts of the state of Punjab. Iron was found exceeding the permissible limit in the villages like, Moran wara (Firozepur), Churian (Firozepur), Manewal (Ludhiana), PandKhokhan (Muktsar) and Pakki Kalan (Faridkot).
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| 7. |
- Maurya, Naresh Chandra, et al.
(författare)
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Exciton many-body interactions and charge transfer in CsPbBr3/graphene derivatives
- 2023
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Ingår i: Physical Review B. - : American Physical Society. - 2469-9950 .- 2469-9969. ; 108:15
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Tidskriftsartikel (refereegranskat)abstract
- Charge separation and many-body interactions at the interface of the light-absorbing semiconductor and contact layer are of crucial importance to the photophysical properties and optoelectronic device performance. Here, we report the exciton many-body interactions and charge transfer dynamics at the interface of metal halide perovskite nanocrystals and graphene derivatives [graphene oxide (GO) and reduced GO (RGO)] using ultrafast transient absorption (TA) and time-resolved photoluminescence (PL) measurements. At the early timescales, the TA spectra of CsPbBr3/GO and CsPbBr3/RGO show an asymmetric derivative feature originating from the exciton many-body interactions. The band gap renormalization and binding energies of exciton and biexciton of CsPbBr3 nanocrystals are significantly reduced in CsPbBr3/GO(RGO) due to the charge transfer and change in the dielectric environment, respectively. More specifically, the exciton (biexciton) binding energy of CsPbBr3 nanocrystals, originally 38 +/- 2 (34 +/- 1) meV, decreases to 27 +/- 1 (22 +/- 1) meV in CsPbBr3/RGO and 17 +/- 1 (15 +/- 1) meV in CsPbBr3/GO. Furthermore, we observe a reduction in the Auger recombination rate and exciton PL quenching in CsPbBr3/GO and CsPbBr3/RGO, corroborating the charge transfer mechanism. Our systematic studies successfully describe photoexcited charge transfer from CsPbBr3 nanocrystals to GO (RGO) in 7.0 +/- 0.4 (4.2 +/- 0.1) ps, which is one order of magnitude faster than the charge transfer for other acceptor materials such as metal oxide, fullerene, anthraquinone, 1-aminopyrene, and phenothiazine. Our results offer insights and guidance for perovskite-based high-performance optoelectronic devices.
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| 8. |
- Patel, Alok, Dr. 1989-, et al.
(författare)
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Extraction of lipids from algae using supercritical carbon dioxide
- 2020
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Ingår i: Green Sustainable Process for Chemical and Environmental Engineering and Science. - : Elsevier. ; , s. 17-39
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Microalgal oils are considered an important source of industrially valuable oleochemicals with significant applications ranging from the energy to pharmaceutical sectors. Industrial production of microalgal oil is emerging rapidly; however, the high cost associated with downstream processes may constrain this process. Oils are accumulated intracellularly in oleaginous microalgae in the form of lipid droplets, which in turn require cell wall disruption followed by extraction in order to recover them. Disruption of the microalgal cell is very challenging owing to its distinctive features like high water content, hard cell wall, presence of algaenan, and sporopollenin like biopolymers that in turn create hurdles in efficient extraction of lipids. Various conventional pretreatment methods have been explored to rupture the cellular integrity of microalgal cells to enhance lipid extraction, and each method has certain advantages and disadvantages. Supercritical fluid extraction is the oldest technique for the extraction of valuable compounds from microalgae and is considered an alternative to conventional solvent extraction methods. It has several advantageous features such as being free from organic solvents (and their disposal), environment-friendly, and operating at a mild range of temperature (40–80°C). CO2 is considered to be an ideal supercritical fluid due to its non-toxic, non-flammable, and lipophilic nature. In this chapter, use of supercritical carbon dioxide extraction of lipids from microalgae is discussed and compared with other available lipid extraction methods.
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