Treatment of tobacco dust represents an important problem because of high concentrations of organ... more Treatment of tobacco dust represents an important problem because of high concentrations of organic compounds, expressed as COD concentration. This research investigated an aerobic biodegradation of leachate from tobacco dust with high concentrations of COD. Experiments were conducted by activated sludge process in batch conditions with different initial concentrations of leachate and different initial concentrations of activated sludge (3.0, 6.0 g dm-3) during 7 hours. Experiments were called Exp. 1 and Exp. 2 with respect to initial concentrations of activated sludge. Values of COD removal efficiency varied from 54.9 to 71.3 % for Exp. 1 and from 59.0 to 77.7 % for Exp. 2. Biokinetic analysis was conducted according to the Monod model. This model gives very good fits to experimental data, accompanied by a high correlation coefficient (R2).
Treatment of tobacco dust leachate represents an important problem because of high concentrations... more Treatment of tobacco dust leachate represents an important problem because of high concentrations of organic compounds. Experiments were carried out in a batch conditions at initial concentrations of activated sludge of 3.1 g dm-3 (Exp.1) and 6.0 g dm-3 (Exp.2) and different initial concentrations of organic matter in leachate, expressed as COD concentrations, which were in range from 500 to 5000 mg dm-3. Efficiency of biodegradation process was approximately 89.4 % of COD removal. The kinetic parameters, maximum specific growth rate (µ max), substrate saturation constant (K s) and overall yield coefficient (Y), during experiments were found to be 0.088 h-1 , 4241 mg dm-3 , and 0.400 mg mg-1 for Exp. 1; and 0.052 h-1 , 3168 mg dm-3 , and 0.257 mg mg-1 for Exp. 2, respectively. Monod model gives very good fits to experimental data, accompanied by a high regression coefficient (R 2).
In this study, the sorption of ammonium from aqueous solution onto activated carbon, natural zeol... more In this study, the sorption of ammonium from aqueous solution onto activated carbon, natural zeolite, peat and potting soil was studied by performing batch kinetic sorption experiments. The activated carbon wasn't efficiently removing ammonium at concentrations higher than 50 mg L(-1). Sorption isotherms of ammonium on zeolite, peat and potting soil were determined at 25 degrees C and 200 rpm with the initial concentration of 50-7000 mg L(-1). Equilibrium data were fitted by Freundlich, Langmuir and Temkin isotherm and parameters were evaluated according these models. Langmuir model gives better fit to experimental data than Freundlich and Temkin models. Maximum adsorption capacities were for activated carbon 0.631 mg g(-1), zeolite 58 mg g(-1), peat 595 mg g(-1) and for potting soil 575 mg g(-1). The equilibrium kinetic data were analyzed using adsorption kinetic models: the pseudo-first and second-order equations and were found to follow the pseudo-second-order kinetic model. ...
This research was initiated to characterize the biodegradability of leachate from composting toba... more This research was initiated to characterize the biodegradability of leachate from composting tobacco waste. Leachate that originated from tobacco waste has high concentrations of chemical oxygen demand (COD). Experiments were conducted in a batch reactor with different initial concentrations of leachate (500, 1000, and 1500 mg dm-3), and initial concentration of activated sludge (5.8 g dm-3) during of 48 hours. The results of the mixed liquor suspended solids (MLSS) concentrations were between 6.38 g dm-3-6.74 g dm-3. The ratio of MLVSS/MLSS was in the range 0.69-0.70. The pH values and dissolved oxygen (DO) were about 7.02 and between 5.90 to 5.44 g dm-3. The COD was reduced by 62 % and resulted to 13.9 % increase in MLSS. The feed to microorganism (F/M) ratio varied from 0.29 to 0.49 g COD (g MLSS)-1 d-1. The specific oxygen uptake rate, SOUR varied between 0.16 and 1.31 mg O 2 (g MLVSS)-1 d-1. Mean floc size increased by about 24 % within the first 24 h.
The beer market today shows extremely diverse styles and offers many possibilities for consumers ... more The beer market today shows extremely diverse styles and offers many possibilities for consumers to try new aromas and tastes. Most modern breweries have a similar technology and equipment and use quality raw materials, but the differences between beers’ physical–chemical properties are always detectable. In ensuring the same beer quality is being delivered to the consumers, sensory analysis is in some cases even more important than the chemical or physical–chemical analysis, since consumers focus on constant quality and sensory properties of their chosen beer. Sensory evaluation is not an easy task and involves flexible methods for determination of differences and changes between beers. It is commonly used in breweries to provide a constant quality in finished products, but also to ensure the quality of different raw materials (water, malt, hops) and to minimize the influence of the production process on final quality of beer. The results of this research indicate that sensory anal...
A pilot-scale composting of tobacco waste was conducted in two thermally insulated, forcefully ae... more A pilot-scale composting of tobacco waste was conducted in two thermally insulated, forcefully aerated reactors to determine the effect of intermittent stirring on the composting performance. The first two experiments were carried out in a 240 dm3 packed bed reactor at airflow rate of 0.65 dm3 min-1 kgVSinitial-1 ; the first experiment was carried out without stirring (PBRNS) ; during the second experiment reactor was periodically opened and the substrate was manually stirred (PBRS). The third experiment was conducted in a 200 dm3 horizontal reactor with stirrers (HRS) at airflow rate of 0.38 dm3 min-1 kgVSinitial-1. Substrate was automatically agitated every 24 hours for 1 minute with the stirring rate of 6.3 rpm. During the composting in PBRNS there was a significant temperature distribution over the bed height. At the end of the processes in PBRNS, PBRS and HRS conversions of the volatile matter were 50.6% (at 38. day), 53.0% (at 28. day) and 51.1% (at 29. day), respectively, sho...
This paper presents kinetic analyses of biodegradation of organic matter from leachate which is p... more This paper presents kinetic analyses of biodegradation of organic matter from leachate which is produced during the composting process of tobacco waste. Four different kinetic models were applied to the data. The kinetic analysis was performed with traditional Monod model, modified Monod model with endogenous metabolism, Haldane model and Haldane model which is expanded with endogenous metabolic consumption and called Endo-Haldane model. Kinetic parameters for each model were determined using differential analysis and the Nelder-Mead method of nonlinear regression. The lowest deviations and very good matches with experimental data were achieved using Endo-Haldane model. This fact pointed out that this model best described the process of biodegradation of leachate from tobacco waste composting. This is due to fact that this model incorporates both, effects of inhibition and endogenous metabolism.
Treatment of wastes and leachate evolved in landfills is today an imperative due to rigorous envi... more Treatment of wastes and leachate evolved in landfills is today an imperative due to rigorous environmental protection legislation. In this work, biodegradation of the organic fraction in tobacco waste leachate was studied. Experiments were carried out in a sequencing batch reactor at initial concentrations of activated sludge of 3.03 and 5.95 g L-1 and different initial concentrations of organic matter in leachate, expressed as COD concentrations, ranging from 0.5 to 3.0 g L-1. The results of the experiments showed that activated sludge possessed a strong ability to degrade organic matter in leachate. Efficiency of the biodegradation process was approximately 82.6 %. A simple Monod equation was selected to describe the kinetics of leachate biodegradation. The kinetic parameters Y, k d , m max and K s during experiments E1 and E2 were found to be 0.25 g g-1 , 0.005 d-1 , 0.39 d-1 and 5.45 g L-1 , and 0.23 g g-1 , 0.003 d-1 , 0.44 d-1 and 5.63 g L-1 , respectively.
The aim of this work was to compare and evaluate composting efficiencies of originally wet (OWT) ... more The aim of this work was to compare and evaluate composting efficiencies of originally wet (OWT) and pre-dried (PDT) tobacco solid waste from cigarette manufacturing. The effect of drying on the biodegradability of the tobacco waste was also investigated. OWT with moisture content (MC) of 75.7 % was dried on a tray at ambient conditions for 23 days and resulted as PDT. Before composting, water was added to the PDT and the MC of the starting material was set to 60 %. Composting experiments were conducted in a thermally insulated column reactor with working volume of 24 L. The substrate inside the reactor was forcefully aerated at airflow rate of 1.5 L min-1. During the composting, as well as drying experiments, pH-value, C/N ratio, organic matter content (OM), MC, and nicotine content were determined at preset times. At the end of the drying experiment 0.096 g of OM was degraded per 1 g of initial dry matter (gOM gDMinit-1). The composting experiments with OWT and PDT were conducted for 27 and 13 days, respectively, while 0.434 and 0.449 gOM gDMinit-1 were degraded, which showed higher efficiency of the process where PDT was used as a composting substrate. During the drying experiment about 50 % of nicotine was degraded while nicotine was completely degraded at the end of both composting experiments. The biodrying process could be recommended as a pre- treatment of wet tobacco solid waste intended for composting but further investigations are needed on the process performance and optimization.
Tobacco waste poses an important environmental problem as some main components of tobacco waste a... more Tobacco waste poses an important environmental problem as some main components of tobacco waste are harmful and toxic, primarily nicotine. Bioaugmentation of the activated sludge system with specialized bacterial strains may be a powerful way to improve several aspects of wastewater treatment, including a rapid reduction of toxicity to the microbial community. The aim of this work was to study the efficiency of biodegradation of organic pollutants in laboratory prepared leachate from tobacco dust waste under batch conditions using Pseudomonas aeruginosa FN and bioaugmented activated sludge with bacterial culture of P. aeruginosa FN. According to classification scale, leachate was classified as ‘very toxic’ (TII50 = 17). The biodegradability criterion for wastewater is the ratio of BOD5/COD, which was 0.54 in the leachate medium. The relatively higher values of ratio indicate pollution of the leachate by biodegradable matter. The microscopic analysis was conducted to study the development of activated sludge flocs and its morphology. Leachate sample was found to be biodegradable since more than 72 % COD was removed and complete degradation of nicotine was accomplished.
Composting is a biological treatment in which aerobic mesophilic and thermophilic microorganisms ... more Composting is a biological treatment in which aerobic mesophilic and thermophilic microorganisms transform the biodegradable organic matter into CO 2 and H 2 O, as well as into more stable organic matter. Two major byproducts of microbial transformation during biodegradation of solid waste are carbon dioxide (CO 2) and ammonia (NH 3). Carbon dioxide is a greenhouse gas, while ammonia is a noxious, toxic gas that can cause serious damage to human health and to the environment. Therefore, it is important that studies be carried out to find ways to efficiently control the emission of these gases. The purpose of this work was to investigate sorption of gases, ammonia and carbon dioxide, on different sorbents during composting of mixture of tobacco waste and grape marcs. Composting process was carried out with forced aeration (0.645 dm 3 min -1 kg VS -1) in column reactor (10 dm 3) under adiabatic conditions during 21 days. During the process, temperature changes in the reactor, pH value...
Two major gaseous byproducts of microbial transformation during aerobic biodegradation of solid w... more Two major gaseous byproducts of microbial transformation during aerobic biodegradation of solid waste are carbon dioxide (CO 2) and ammonia (NH 3). As is well known that CO 2 is the greenhouse gas and NH 3 is a noxious, toxic gas. It is important to find ways to efficiently control and remove these gases from waste gaseous streams. The purpose of this work was to investigate sorption of ammonia and carbon dioxide on zeolite during composting of winery and tobacco waste mixture. Composting experiments were carried out with forced aeration in thermally insulated packed bed reactor (10 dm 3 of working volume) during 16 days. During the process, temperature changes in the reactor were continuously monitored and evolved CO 2 and NH 3 in the gaseous stream, pH value, C/N ratio, volatile solids content and mesophilic and thermophilic microorganisms in the composting mass were determined periodically. At the end of the composting process 54% of volatile solids were degraded and zeolite show...
The tobacco industry produces large quantities of solid and liquid waste. This waste poses a sign... more The tobacco industry produces large quantities of solid and liquid waste. This waste poses a significant environmental problem, as some major components are harmful and toxic. The aim of this work is to isolate and identify the nicotine-degrading microorganisms in the composting of tobacco waste. The bioremediation process for the detoxification of waste was carried out in a column reactor at an airflow-rate of 0.4 L min−1 kg−1. The concentrations of nicotine and number of CFU in the samples taken from reactor were monitored over nineteen days. After nineteen days, 89.8 % of nicotine conversion was obtained. A nicotine-degrading bacterium, strain FN, was isolated from the composting mass and identified as Pseudomonas aeruginosa on the basis of morphology, 16S rDNA sequence, and the phylogenetic characteristics. To confirm that the isolated Pseudomonas aeruginosa FN is the actual nicotine degrader, batch experiments were performed using tobacco leachate. It was confirmed that the str...
This paper presents a kinetic analysis of the biodegradation of organic pollutants in a batch bio... more This paper presents a kinetic analysis of the biodegradation of organic pollutants in a batch bioreactor and investigates the kinetic properties of activated sludge using different mathematical models. The treatment was conducted for different initial concentrations of leachate from 500 mg dm−3 to 5000 mg dm−3 and initial concentrations of activated sludge from 1.84 g dm−3 to 6.62 g dm−3 over 48 h. Four different kinetic models were applied to the data. The kinetic analysis was performed with the traditional Monod model, the modified Monod model with endogenous metabolism, the Haldane model, and the Haldane model extended to include endogenous metabolic consumption and known as the Endo-Haldane model. Kinetic parameters for each model were determined using differential analysis and the Nelder-Mead method of non-linear regression. The lowest deviations and very good matches with the experimental data were achieved using the Endo-Haldane model. This indicated that this model best desc...
Brewers commonly produce ales since the ale yeast is more resilient, ferments quicker and require... more Brewers commonly produce ales since the ale yeast is more resilient, ferments quicker and requires higher temperatures, which are easier to ensure as opposed to lager and pilsner, which require lower temperatures and longer lagering time. However, Kveik yeasts are also resilient, ferment at fairly high temperatures (up to 35 °C), and can provide light, lager-like beers, but more quickly, in shorter lagering time, and with reduced off flavors. Diacetyl rest is not needed. The intention of this paper was to assess the possibility of producing pseudo-lager by using Lutra® Kveik. A batch (120 L) was divided into six fermenting vessels and inoculated with Lutra® yeast. To test its possibility to result in lager-like beer at higher temperature, we conducted fermentation at two temperatures (21 and 35 °C). Fermentation subjected to 21 °C lasted for 9 days, while at 35 °C, fermentation was finished in 2 days. After fermentation, both beers were stored in cold temperatures (4 °C) and then ke...
This paper presents kinetic analyses of biodegradation of organic matter from leachate which is p... more This paper presents kinetic analyses of biodegradation of organic matter from leachate which is produced during the composting process of tobacco waste. Four different kinetic models were applied to the data. The kinetic analysis was performed with traditional Monod model, modified Monod model with endogenous metabolism, Haldane model and Haldane model which is expanded with endogenous metabolic consumption and called Endo-Haldane model. Kinetic parameters for each model were determined using differential analysis and the Nelder-Mead method of nonlinear regression. The lowest deviations and very good matches with experimental data were achieved using Endo-Haldane model. This fact pointed out that this model best described the process of biodegradation of leachate from tobacco waste composting. This is due to fact that this model incorporates both, effects of inhibition and endogenous metabolism.
Treatment of tobacco dust represents an important problem because of high concentrations of organ... more Treatment of tobacco dust represents an important problem because of high concentrations of organic compounds, expressed as COD concentration. This research investigated an aerobic biodegradation of leachate from tobacco dust with high concentrations of COD. Experiments were conducted by activated sludge process in batch conditions with different initial concentrations of leachate and different initial concentrations of activated sludge (3.0, 6.0 g dm-3) during 7 hours. Experiments were called Exp. 1 and Exp. 2 with respect to initial concentrations of activated sludge. Values of COD removal efficiency varied from 54.9 to 71.3 % for Exp. 1 and from 59.0 to 77.7 % for Exp. 2. Biokinetic analysis was conducted according to the Monod model. This model gives very good fits to experimental data, accompanied by a high correlation coefficient (R2).
Treatment of tobacco dust leachate represents an important problem because of high concentrations... more Treatment of tobacco dust leachate represents an important problem because of high concentrations of organic compounds. Experiments were carried out in a batch conditions at initial concentrations of activated sludge of 3.1 g dm-3 (Exp.1) and 6.0 g dm-3 (Exp.2) and different initial concentrations of organic matter in leachate, expressed as COD concentrations, which were in range from 500 to 5000 mg dm-3. Efficiency of biodegradation process was approximately 89.4 % of COD removal. The kinetic parameters, maximum specific growth rate (µ max), substrate saturation constant (K s) and overall yield coefficient (Y), during experiments were found to be 0.088 h-1 , 4241 mg dm-3 , and 0.400 mg mg-1 for Exp. 1; and 0.052 h-1 , 3168 mg dm-3 , and 0.257 mg mg-1 for Exp. 2, respectively. Monod model gives very good fits to experimental data, accompanied by a high regression coefficient (R 2).
In this study, the sorption of ammonium from aqueous solution onto activated carbon, natural zeol... more In this study, the sorption of ammonium from aqueous solution onto activated carbon, natural zeolite, peat and potting soil was studied by performing batch kinetic sorption experiments. The activated carbon wasn't efficiently removing ammonium at concentrations higher than 50 mg L(-1). Sorption isotherms of ammonium on zeolite, peat and potting soil were determined at 25 degrees C and 200 rpm with the initial concentration of 50-7000 mg L(-1). Equilibrium data were fitted by Freundlich, Langmuir and Temkin isotherm and parameters were evaluated according these models. Langmuir model gives better fit to experimental data than Freundlich and Temkin models. Maximum adsorption capacities were for activated carbon 0.631 mg g(-1), zeolite 58 mg g(-1), peat 595 mg g(-1) and for potting soil 575 mg g(-1). The equilibrium kinetic data were analyzed using adsorption kinetic models: the pseudo-first and second-order equations and were found to follow the pseudo-second-order kinetic model. ...
This research was initiated to characterize the biodegradability of leachate from composting toba... more This research was initiated to characterize the biodegradability of leachate from composting tobacco waste. Leachate that originated from tobacco waste has high concentrations of chemical oxygen demand (COD). Experiments were conducted in a batch reactor with different initial concentrations of leachate (500, 1000, and 1500 mg dm-3), and initial concentration of activated sludge (5.8 g dm-3) during of 48 hours. The results of the mixed liquor suspended solids (MLSS) concentrations were between 6.38 g dm-3-6.74 g dm-3. The ratio of MLVSS/MLSS was in the range 0.69-0.70. The pH values and dissolved oxygen (DO) were about 7.02 and between 5.90 to 5.44 g dm-3. The COD was reduced by 62 % and resulted to 13.9 % increase in MLSS. The feed to microorganism (F/M) ratio varied from 0.29 to 0.49 g COD (g MLSS)-1 d-1. The specific oxygen uptake rate, SOUR varied between 0.16 and 1.31 mg O 2 (g MLVSS)-1 d-1. Mean floc size increased by about 24 % within the first 24 h.
The beer market today shows extremely diverse styles and offers many possibilities for consumers ... more The beer market today shows extremely diverse styles and offers many possibilities for consumers to try new aromas and tastes. Most modern breweries have a similar technology and equipment and use quality raw materials, but the differences between beers’ physical–chemical properties are always detectable. In ensuring the same beer quality is being delivered to the consumers, sensory analysis is in some cases even more important than the chemical or physical–chemical analysis, since consumers focus on constant quality and sensory properties of their chosen beer. Sensory evaluation is not an easy task and involves flexible methods for determination of differences and changes between beers. It is commonly used in breweries to provide a constant quality in finished products, but also to ensure the quality of different raw materials (water, malt, hops) and to minimize the influence of the production process on final quality of beer. The results of this research indicate that sensory anal...
A pilot-scale composting of tobacco waste was conducted in two thermally insulated, forcefully ae... more A pilot-scale composting of tobacco waste was conducted in two thermally insulated, forcefully aerated reactors to determine the effect of intermittent stirring on the composting performance. The first two experiments were carried out in a 240 dm3 packed bed reactor at airflow rate of 0.65 dm3 min-1 kgVSinitial-1 ; the first experiment was carried out without stirring (PBRNS) ; during the second experiment reactor was periodically opened and the substrate was manually stirred (PBRS). The third experiment was conducted in a 200 dm3 horizontal reactor with stirrers (HRS) at airflow rate of 0.38 dm3 min-1 kgVSinitial-1. Substrate was automatically agitated every 24 hours for 1 minute with the stirring rate of 6.3 rpm. During the composting in PBRNS there was a significant temperature distribution over the bed height. At the end of the processes in PBRNS, PBRS and HRS conversions of the volatile matter were 50.6% (at 38. day), 53.0% (at 28. day) and 51.1% (at 29. day), respectively, sho...
This paper presents kinetic analyses of biodegradation of organic matter from leachate which is p... more This paper presents kinetic analyses of biodegradation of organic matter from leachate which is produced during the composting process of tobacco waste. Four different kinetic models were applied to the data. The kinetic analysis was performed with traditional Monod model, modified Monod model with endogenous metabolism, Haldane model and Haldane model which is expanded with endogenous metabolic consumption and called Endo-Haldane model. Kinetic parameters for each model were determined using differential analysis and the Nelder-Mead method of nonlinear regression. The lowest deviations and very good matches with experimental data were achieved using Endo-Haldane model. This fact pointed out that this model best described the process of biodegradation of leachate from tobacco waste composting. This is due to fact that this model incorporates both, effects of inhibition and endogenous metabolism.
Treatment of wastes and leachate evolved in landfills is today an imperative due to rigorous envi... more Treatment of wastes and leachate evolved in landfills is today an imperative due to rigorous environmental protection legislation. In this work, biodegradation of the organic fraction in tobacco waste leachate was studied. Experiments were carried out in a sequencing batch reactor at initial concentrations of activated sludge of 3.03 and 5.95 g L-1 and different initial concentrations of organic matter in leachate, expressed as COD concentrations, ranging from 0.5 to 3.0 g L-1. The results of the experiments showed that activated sludge possessed a strong ability to degrade organic matter in leachate. Efficiency of the biodegradation process was approximately 82.6 %. A simple Monod equation was selected to describe the kinetics of leachate biodegradation. The kinetic parameters Y, k d , m max and K s during experiments E1 and E2 were found to be 0.25 g g-1 , 0.005 d-1 , 0.39 d-1 and 5.45 g L-1 , and 0.23 g g-1 , 0.003 d-1 , 0.44 d-1 and 5.63 g L-1 , respectively.
The aim of this work was to compare and evaluate composting efficiencies of originally wet (OWT) ... more The aim of this work was to compare and evaluate composting efficiencies of originally wet (OWT) and pre-dried (PDT) tobacco solid waste from cigarette manufacturing. The effect of drying on the biodegradability of the tobacco waste was also investigated. OWT with moisture content (MC) of 75.7 % was dried on a tray at ambient conditions for 23 days and resulted as PDT. Before composting, water was added to the PDT and the MC of the starting material was set to 60 %. Composting experiments were conducted in a thermally insulated column reactor with working volume of 24 L. The substrate inside the reactor was forcefully aerated at airflow rate of 1.5 L min-1. During the composting, as well as drying experiments, pH-value, C/N ratio, organic matter content (OM), MC, and nicotine content were determined at preset times. At the end of the drying experiment 0.096 g of OM was degraded per 1 g of initial dry matter (gOM gDMinit-1). The composting experiments with OWT and PDT were conducted for 27 and 13 days, respectively, while 0.434 and 0.449 gOM gDMinit-1 were degraded, which showed higher efficiency of the process where PDT was used as a composting substrate. During the drying experiment about 50 % of nicotine was degraded while nicotine was completely degraded at the end of both composting experiments. The biodrying process could be recommended as a pre- treatment of wet tobacco solid waste intended for composting but further investigations are needed on the process performance and optimization.
Tobacco waste poses an important environmental problem as some main components of tobacco waste a... more Tobacco waste poses an important environmental problem as some main components of tobacco waste are harmful and toxic, primarily nicotine. Bioaugmentation of the activated sludge system with specialized bacterial strains may be a powerful way to improve several aspects of wastewater treatment, including a rapid reduction of toxicity to the microbial community. The aim of this work was to study the efficiency of biodegradation of organic pollutants in laboratory prepared leachate from tobacco dust waste under batch conditions using Pseudomonas aeruginosa FN and bioaugmented activated sludge with bacterial culture of P. aeruginosa FN. According to classification scale, leachate was classified as ‘very toxic’ (TII50 = 17). The biodegradability criterion for wastewater is the ratio of BOD5/COD, which was 0.54 in the leachate medium. The relatively higher values of ratio indicate pollution of the leachate by biodegradable matter. The microscopic analysis was conducted to study the development of activated sludge flocs and its morphology. Leachate sample was found to be biodegradable since more than 72 % COD was removed and complete degradation of nicotine was accomplished.
Composting is a biological treatment in which aerobic mesophilic and thermophilic microorganisms ... more Composting is a biological treatment in which aerobic mesophilic and thermophilic microorganisms transform the biodegradable organic matter into CO 2 and H 2 O, as well as into more stable organic matter. Two major byproducts of microbial transformation during biodegradation of solid waste are carbon dioxide (CO 2) and ammonia (NH 3). Carbon dioxide is a greenhouse gas, while ammonia is a noxious, toxic gas that can cause serious damage to human health and to the environment. Therefore, it is important that studies be carried out to find ways to efficiently control the emission of these gases. The purpose of this work was to investigate sorption of gases, ammonia and carbon dioxide, on different sorbents during composting of mixture of tobacco waste and grape marcs. Composting process was carried out with forced aeration (0.645 dm 3 min -1 kg VS -1) in column reactor (10 dm 3) under adiabatic conditions during 21 days. During the process, temperature changes in the reactor, pH value...
Two major gaseous byproducts of microbial transformation during aerobic biodegradation of solid w... more Two major gaseous byproducts of microbial transformation during aerobic biodegradation of solid waste are carbon dioxide (CO 2) and ammonia (NH 3). As is well known that CO 2 is the greenhouse gas and NH 3 is a noxious, toxic gas. It is important to find ways to efficiently control and remove these gases from waste gaseous streams. The purpose of this work was to investigate sorption of ammonia and carbon dioxide on zeolite during composting of winery and tobacco waste mixture. Composting experiments were carried out with forced aeration in thermally insulated packed bed reactor (10 dm 3 of working volume) during 16 days. During the process, temperature changes in the reactor were continuously monitored and evolved CO 2 and NH 3 in the gaseous stream, pH value, C/N ratio, volatile solids content and mesophilic and thermophilic microorganisms in the composting mass were determined periodically. At the end of the composting process 54% of volatile solids were degraded and zeolite show...
The tobacco industry produces large quantities of solid and liquid waste. This waste poses a sign... more The tobacco industry produces large quantities of solid and liquid waste. This waste poses a significant environmental problem, as some major components are harmful and toxic. The aim of this work is to isolate and identify the nicotine-degrading microorganisms in the composting of tobacco waste. The bioremediation process for the detoxification of waste was carried out in a column reactor at an airflow-rate of 0.4 L min−1 kg−1. The concentrations of nicotine and number of CFU in the samples taken from reactor were monitored over nineteen days. After nineteen days, 89.8 % of nicotine conversion was obtained. A nicotine-degrading bacterium, strain FN, was isolated from the composting mass and identified as Pseudomonas aeruginosa on the basis of morphology, 16S rDNA sequence, and the phylogenetic characteristics. To confirm that the isolated Pseudomonas aeruginosa FN is the actual nicotine degrader, batch experiments were performed using tobacco leachate. It was confirmed that the str...
This paper presents a kinetic analysis of the biodegradation of organic pollutants in a batch bio... more This paper presents a kinetic analysis of the biodegradation of organic pollutants in a batch bioreactor and investigates the kinetic properties of activated sludge using different mathematical models. The treatment was conducted for different initial concentrations of leachate from 500 mg dm−3 to 5000 mg dm−3 and initial concentrations of activated sludge from 1.84 g dm−3 to 6.62 g dm−3 over 48 h. Four different kinetic models were applied to the data. The kinetic analysis was performed with the traditional Monod model, the modified Monod model with endogenous metabolism, the Haldane model, and the Haldane model extended to include endogenous metabolic consumption and known as the Endo-Haldane model. Kinetic parameters for each model were determined using differential analysis and the Nelder-Mead method of non-linear regression. The lowest deviations and very good matches with the experimental data were achieved using the Endo-Haldane model. This indicated that this model best desc...
Brewers commonly produce ales since the ale yeast is more resilient, ferments quicker and require... more Brewers commonly produce ales since the ale yeast is more resilient, ferments quicker and requires higher temperatures, which are easier to ensure as opposed to lager and pilsner, which require lower temperatures and longer lagering time. However, Kveik yeasts are also resilient, ferment at fairly high temperatures (up to 35 °C), and can provide light, lager-like beers, but more quickly, in shorter lagering time, and with reduced off flavors. Diacetyl rest is not needed. The intention of this paper was to assess the possibility of producing pseudo-lager by using Lutra® Kveik. A batch (120 L) was divided into six fermenting vessels and inoculated with Lutra® yeast. To test its possibility to result in lager-like beer at higher temperature, we conducted fermentation at two temperatures (21 and 35 °C). Fermentation subjected to 21 °C lasted for 9 days, while at 35 °C, fermentation was finished in 2 days. After fermentation, both beers were stored in cold temperatures (4 °C) and then ke...
This paper presents kinetic analyses of biodegradation of organic matter from leachate which is p... more This paper presents kinetic analyses of biodegradation of organic matter from leachate which is produced during the composting process of tobacco waste. Four different kinetic models were applied to the data. The kinetic analysis was performed with traditional Monod model, modified Monod model with endogenous metabolism, Haldane model and Haldane model which is expanded with endogenous metabolic consumption and called Endo-Haldane model. Kinetic parameters for each model were determined using differential analysis and the Nelder-Mead method of nonlinear regression. The lowest deviations and very good matches with experimental data were achieved using Endo-Haldane model. This fact pointed out that this model best described the process of biodegradation of leachate from tobacco waste composting. This is due to fact that this model incorporates both, effects of inhibition and endogenous metabolism.
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Papers by Ivana Ćosić