Faculty Publications
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Item Investigation of physical and chemical characteristics on soil due to crude oil contamination and its remediation(Springer Verlag, 2019) Devatha, C.P.; Vishnu Vishal, A.; Purna Chandra Rao, J.Oil contamination causes serious geoenvironmental concern and adversely affects the soil environment due to the release of toxic by-products. Hence, the aim of the study was to investigate the influence of oil contamination on soil physical and chemical properties and phytoremediation as a treatment option based on field studies conducted for analyzing significant parameters. The sites selected were near National Institute of Technology, Surathkal, Karnataka (site-1), and another is close to the oil refinery (Kuthethur, Karnataka, India, as site-2). Phytoremediation of oil-contaminated samples was carried out by Chromolaena odorata. The evaluation of soil physical and chemical properties includes field and laboratory tests. A pumping test was conducted to estimate aquifer parameters in the field. The hydraulic conductivity for field soil sample (unsaturated condition) is carried out by a filter paper test. Laboratory tests to evaluate physical and chemical parameters include total petroleum hydrocarbons of contaminated (crude oil varying from 0 to 10% at an interval of 2%) and uncontaminated samples and plant parameters. Characterization of contaminated and uncontaminated soil sample was performed by Fourier transform infrared (FTIR) spectroscopy. The results obtained reveal that physical properties of soil (moisture content, liquid and plastic limit) got affected due to oil contamination. Relative hydraulic conductivity was established as 0.46 (uncontaminated) and 0.57 (contaminated) for soil samples and led to the conclusion that hydraulic conductivity was drop down by 10% due to oil contamination. Total petroleum hydrocarbon analysis reveals that the uptake/presence of hydrocarbons by showing increased concentration in contaminated soils (5% and 10%) by the plant species. This is further confirmed by FTIR results. The TPH concentrations in the contaminated soils were reduced up to 50–60% and also showed better plant growth after 7 weeks of transplantation. Hence, considered plant species possess high potential for degrading oil contaminated in the soil. © 2019, The Author(s).Item Experimental investigation for treating ibuprofen and triclosan by biosurfactant from domestic wastewater(Academic Press, 2023) Jayalatha, N.A.; Devatha, C.P.The presence of emerging pollutants of pharmaceutical products and personal care products (PPCPs) in the aquatic environment overspreads the threat on living beings. Bioremediation is a promising option for treating wastewater. In the present study, an experimental investigation was carried out to produce a biosurfactant by Pseudomonas aeruginosa (MTCC 1688) for the removal of Ibuprofen (IBU) and Triclosan (TCS) from domestic wastewater. It was performed in three stages. Firstly, the production and optimization of biosurfactant was carried out to arrive at the best combination of crude sunflower oil, sucrose and ammonium bicarbonate (10%: 5.5 g/L: 1 g/L) to yield effective biosurfactant production (crude biosurfactant) and further extended to achieve critical micelle concentration (CMC) formation by dilution (biosurfactant at 10.5%). The stability of the biosurfactant was also confirmed. Biosurfactant showed a reduction in the surface tension to 41 mN/m with a yield concentration of 11.2 g/L. Secondly, its effectiveness was evaluated for the removal of IBU and TCS from the domestic wastewater collected during the dry and rainy seasons. Complete removal of IBU was achieved at 36 h & 6 h and TCS at 6 h & 1 h by crude biosurfactant and biosurfactant at CMC formation for the dry season sample. IBU removal was achieved in 2 h by both crude and biosurfactant at CMC and no TCS was detected in the rainy season sample. Thirdly, biotransformation intermediates of IBU and TCS formed during the application of the biosurfactant and degradation pathways are proposed based on the Liquid Chromatography-Mass Spectrometry (LC-MS) and it indicates that there is no formation of toxic by-products. Based on the results, it is evident that biosurfactant at CMC has performed better for the removal of IBU and TCS than crude biosurfactants without any formation of toxic intermediates. Hence, this study proved to be an eco-friendly, cost-effective and sustainable treatment option for domestic wastewater treatment. © 2022 Elsevier Ltd