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Utilization of molasses spentwash for production of bioplastics by waste activated sludge

Environmental Genomics Unit, National Environmental Engineering Research Institute, Nehru Marg, Nagpur 440 020, India.
Waste Management (Impact Factor: 3.16). 07/2009; 29(9):2558-65. DOI: 10.1016/j.wasman.2009.04.008
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ABSTRACT Present study describes the treatment of molasses spentwash and its use as a potential low cost substrate for production of biopolymer polyhydroxybutyrate (PHB) by waste activated sludge. Fluorescence microscopy revealed the presence of PHB granules in sludge biomass which was further confirmed by fourier transform-infra-red spectroscopy (FT-IR) and (13)C nuclear magnetic resonance (NMR). The processing of molasses spentwash was carried out for attaining different ratios of carbon and nitrogen (C:N). Highest chemical oxygen demand (COD) removal and PHB accumulation of 60% and 31% respectively was achieved with raw molasses spentwash containing inorganic nitrogen (C:N ratio=28) followed by COD removal of 52% and PHB accumulation of 28% for filtered molasses containing inorganic nitrogen (C:N ratio=29). PHB production yield (Y(p/s)) was highest (0.184 g g(-1) COD consumed) for deproteinized spentwash supplemented with nitrogen. In contrast, the substrate consumption and product formation were higher in case of raw spentwash. Though COD removal was lowest from deproteinized spentwash, evaluation of kinetic parameters suggested higher rates of conversion of available carbon to biomass and PHB. Thus the process provided dual benefit of conversion of two wastes viz. waste activated sludge and molasses spentwash into value-added product-PHB.

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    • "Vinasse is one of the most difficult waste products to dispose because of low pH, high temperature, dark brown color, high ash content and high percentage of dissolved organic and inorganic matter (Pant and Adholeya, 2007). In attempts to utilize vinasse as a low cost carbon source for commercial synthesis of PHAs, polyhydroxybutyrate (PHB) was produced from spent wash obtained from a distillery producing ethanol by fermentation of sugarcane molasses (Khardenavis et al. 2009) as well as rice grain and jowar grain based distillery vinasse (Khardenavis et al. 2007) by mixed culture of microbes. Halophilic microorganisms are an important source of PHAs and hold promise for providing an economically competitive industrial scale production process. "
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    07/2012; 2(1):34. DOI:10.1186/2191-0855-2-34
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    ABSTRACT: Molasses-based distilleries are one of the most vulnerable to pollution industries, which always generate large volumes of high strength vinasse. Recently, one of the most effective re-applications/reuse of vinasse is concentrating the molasses vinasse to prepare as fodder additive for animal food. However, the dosage of molasses vinasse to be added as animal feed is always limited because of the unexpectedly high potassium content in molasses vinasse. In present study, potassium ions were firstly extracted from molasses vinasses using a strong acid–cation exchange resin, and then desorbed from the resin and dissolved into the eluate by H2SO4 solution as the strong acid–cation exchange resin was regenerated. Finally, evaluation to recycle and reuse the mother liquor (once-used eluant), after extracting K2SO4 crystals from the eluant, was investigated. Results indicated that using the mother liquor to elute the resin column which absorbing K+ from molasses vinasse was a potential means for industrial production of potassium salt. Meanwhile, the molasses vinasse which has removed most potassium ions might be used as animal feed.
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