Browsing by Author "Kavitha, S."

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    Effect of chemo-mechanical disintegration on sludge anaerobic digestion for enhanced biogas production
    (Springer Verlag, 2016) Kavitha, S.; Saji Pray, S.; Yogalakshmi, K.N.; Adish Kumar, S.; Yeom, I.-T.; Rajesh banu, J.
    The effect of combined surfactant-dispersion pretreatment on dairy waste activated sludge (WAS) reduction in anaerobic digesters was investigated. The experiments were performed with surfactant, Sodium dodecyl sulfate (SDS) in the range of 0.01 to 0.1?g/g suspended solids (SS) and disperser with rpm of 5000?25,000. The COD (chemical oxygen demand) solubilization, suspended solids reduction, and biogas generation increased for an energy input of 7377?kJ/kg total solids (TS) (12,000?rpm, 0.04?g/g SS, and 30?min) and were found to be 38, 32, and 75?%, higher than that of control. The pretreated sludge improved the performance of semicontinuous anaerobic digesters of 4?L working volume operated at four different SRTs (sludge retention time). SRT of 15?days was found to be appropriate showing 49 and 51?% reduction in SS and volatile solids (VS), respectively. The methane yield of the pretreated sample was observed to be 50?mL/g VS removed which was observed to be comparatively higher than the control (12?mL/g VS removed) at optimal SRT of 15?days. To the best of the authors? knowledge, this study is the first to be reported and not yet been documented in literature. ? 2015, Springer-Verlag Berlin Heidelberg.
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    Effect of enzyme secreting bacterial pretreatment on enhancement of aerobic digestion potential of waste activated sludge interceded through EDTA
    (Elsevier Ltd, 2013) Kavitha, S.; Adish Kumar, S.; Yogalakshmi, K.N.; Kaliappan, S.; Rajesh Banu, J.
    In this study, the effect of Ethylene diamine tetra acetic acid (EDTA) on Extracellular polymeric substance (EPS) removal tailed with bacterial enzymatic pretreatment on aerobic digestion of activated sludge was studied. In order to enhance the accessibility of sludge to the enzyme secreting bacteria; the extracellular polymeric substances were removed using EDTA. EDTA efficiently removed the EPS with limited cell lysis and enhanced the sludge enzyme activity at its lower concentration of 0.2. g/g SS. The sludge was then subjected to bacterial pretreatment to enhance the aerobic digestion. In aerobic digestion the best results in terms of Suspended solids (SS) reduction (48.5%) and COD (Chemical oxygen demand) solubilization (47.3%) was obtained in experimental reactor than in control. These results imply that aerobic digestion can be enhanced efficiently through bacterial pretreatment of EPS removed sludge. ? 2013 Elsevier Ltd.
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    Lignocellulosic Biorefinery Technologies: A Perception into Recent Advances in Biomass Fractionation, Biorefineries, Economic Hurdles and Market Outlook
    (MDPI, 2023-03-01T00:00:00) K.N, Yogalakshmi; T.M, Mohamed Usman; Kavitha, S.; Sachdeva, Saloni; Thakur, Shivani; Adish Kumar, S.; J, Rajesh Banu
    Lignocellulosic biomasses (LCB) are sustainable and abundantly available feedstocks for the production of biofuel and biochemicals via suitable bioconversion processing. The main aim of this review is to focus on strategies needed for the progression of viable lignocellulosic biomass-based biorefineries (integrated approaches) to generate biofuels and biochemicals. Processing biomass in a sustainable manner is a major challenge that demands the accomplishment of basic requirements relating to cost effectiveness and environmental sustainability. The challenges associated with biomass availability and the bioconversion process have been explained in detail in this review. Limitations associated with biomass structural composition can obstruct the feasibility of biofuel production, especially in mono-process approaches. In such cases, biorefinery approaches and integrated systems certainly lead to improved biofuel conversion. This review paper provides a summary of mono and integrated approaches, their limitations and advantages in LCB bioconversion to biofuel and biochemicals. � 2023 by the authors.