World Journal of Microbiology and Biotechnology, 2001
... Szilvia JaÈger1, Aniko Brumbauer2, Erika FeheÂr1, Kati ReÂczey2 and LaÂszlo Kiss1,* 1Instit... more ... Szilvia JaÈger1, Aniko Brumbauer2, Erika FeheÂr1, Kati ReÂczey2 and LaÂszlo Kiss1,* 1Institute of Biochemistry, Faculty of Sciences, University of ... Considering these data, similar results were obtained for A. niger by Dekker (1986), McCleary & Harrington (1988), Watanabe ...
Anaerobic digestion is an environmentally sustainable technology for converting a variety of orga... more Anaerobic digestion is an environmentally sustainable technology for converting a variety of organic solid feedstocks to energy in the form of methane. To improve methane yield, the digestion of more than one waste is commonly applied. This study aimed to investigate the dry anaerobic co-digestion (TS of 20%) of vegetable wastes (VW) and animal manures (cow manure (CM) and poultry manure (PM)) through conducting biochemical methane potential (BMP) assays at different substrate to inoculum (S/I) ratio. Fractionation and fluorescence analyses showed that organic matter of VW was less accessible and less complex compared to that of CM and PM. The highest methane yields of mono-digestion experiments were registered with S/I 0.5. Best results of methane yield were observed by the co-digestion of VW and CM (284 mL/g VS), which was about 2.3-fold higher than that of VW mono-fermentation. This finding was confirmed at a laboratory-scale leach bed reactor. Result showed an increase of biogas yield from 220 to 445 mL/g VS, during mono and co-digestion, respectively. The co-digestion of VW and CM mixture led to the enhancement of both methane yield and digestate quality in comparison to mono-digestion.
The phosphate fertilizer industry produces highly hazardous and acidic wastewaters. This study wa... more The phosphate fertilizer industry produces highly hazardous and acidic wastewaters. This study was undertaken to develop an integrated approach for the treatment of wastewaters from the phosphate industry. Effluent samples were collected from a local phosphate fertilizer producer and were characterized by their high fluoride and phosphate content. First, the samples were pretreated by precipitation of phosphate and fluoride ions using hydrated lime. The resulting low- fluoride and phosphorus effluent was then treated with the enhanced biological phosphorus removal (EBPR) process to monitor the simultaneous removal of carbon, nitrogen, and phosphorus. Phosphorus removal included a two-stage anaerobic/aerobic system operating under continuous flow. Pretreated wastewater was added to the activated sludge and operated for 160 days in the reactor. The operating strategy included increasing the organic loading rate (OLR) from 0.3 to 1.2 g chemical oxygen demand (COD)/L.d. The stable and high removal rates of COD, NH4(+)-N, and PO4(3-)-P were then recorded. The mean concentrations of the influent were approximately 3600 mg COD/L, 60 mg N/L, and 14 mg P/L, which corresponded to removal efficiencies of approximately 98%, 86%, and 92%, respectively.
A kinetic study of the photocatalytic degradation of 4-chlorophenol employing titanium dioxide is... more A kinetic study of the photocatalytic degradation of 4-chlorophenol employing titanium dioxide is presented. Experiments were carried out in a cylindrical slurry reactor irradiated by UV lamps. The aromatic reaction intermediates were identified and quantified. Intrinsic expressions to represent the kinetics of 4-chlorophenol and the main intermediates, 4-chlorocatechol and hydroquinone, were derived from a proposed reaction scheme. These expressions include
The tanning industry is of great economic importance worldwide; however, the potential environmen... more The tanning industry is of great economic importance worldwide; however, the potential environmental impact of tanning is significant. An important component in tanning is the removal of hair from the hide (unhairing), a process which generates considerable amounts of toxic effluent characterized by a high concentration of sulphur, rich mineral compounds, a high alkalinity and a high organic load. The purpose of the work described here was to evaluate the biodegradability of the unhairing wastewater by endogenous biomass in batch culture and continuous systems. The detoxification of the effluent was assessed by seed germination tests. The batch culture experiments showed that variations in COD, temperature and pH significantly affected the endogenous biomass growth and activity. The optimal treatment condition corresponded to an initial COD of 6 g/L, pH of 7 and 30 degrees C. Under continuous culture conditions, the reactor was fed for 48 days with the unhairing effluent. The optimal COD removal efficiency was 85.5%. During treatment, a transformation of sulphides into thiosulphates and then sulphates was also observed. The effect of untreated and treated unhairing wastewater on seed germination of different plant species was studied. The data suggested that treatment decreased the wastewater toxicity. Indeed, germination was inhibited when the effluent dilution was lower than 20% and 10% for treated and untreated wastewater, respectively.
International Journal of Environmental Science and Technology
The effect of particle size of the organic fraction of municipal solid waste on methane potentiel... more The effect of particle size of the organic fraction of municipal solid waste on methane potentiel was investigated and tested at different substrate-to-inoculum ratios (0.1, 0.5 and 1.0). The highest methane yield was obtained with particle size fraction > 3 mm at S/I of 0.1. Thermo-alkali and thermo-acid methods were also tested as pretreatment to increase the organic matter solubilization and subsequently methane production. The results indicated that maximum variation (63.6%) of soluble chemical oxygen demand was obtained by thermo-acid method. Optimum conditions of thermo-alkali pretreatment were pH 10, time reaction of 30 min and temperature of 105 °C. Soluble chemical oxygen demand and reducing sugar variations reached, respectively, 40 and 69% under these conditions. The methane yield of untreated and thermochemical pretreated OFMSW was determined in batch condition. The highest methane yield (260.9 L/kg VS) was obtained with thermo-alkali pretreatment, which was 21% higher than that of raw substrate. This study may pave a new way for industrial application of dealing with the organic fraction of municipal solid waste.
World Journal of Microbiology and Biotechnology, 2001
... Szilvia JaÈger1, Aniko Brumbauer2, Erika FeheÂr1, Kati ReÂczey2 and LaÂszlo Kiss1,* 1Instit... more ... Szilvia JaÈger1, Aniko Brumbauer2, Erika FeheÂr1, Kati ReÂczey2 and LaÂszlo Kiss1,* 1Institute of Biochemistry, Faculty of Sciences, University of ... Considering these data, similar results were obtained for A. niger by Dekker (1986), McCleary & Harrington (1988), Watanabe ...
Anaerobic digestion is an environmentally sustainable technology for converting a variety of orga... more Anaerobic digestion is an environmentally sustainable technology for converting a variety of organic solid feedstocks to energy in the form of methane. To improve methane yield, the digestion of more than one waste is commonly applied. This study aimed to investigate the dry anaerobic co-digestion (TS of 20%) of vegetable wastes (VW) and animal manures (cow manure (CM) and poultry manure (PM)) through conducting biochemical methane potential (BMP) assays at different substrate to inoculum (S/I) ratio. Fractionation and fluorescence analyses showed that organic matter of VW was less accessible and less complex compared to that of CM and PM. The highest methane yields of mono-digestion experiments were registered with S/I 0.5. Best results of methane yield were observed by the co-digestion of VW and CM (284 mL/g VS), which was about 2.3-fold higher than that of VW mono-fermentation. This finding was confirmed at a laboratory-scale leach bed reactor. Result showed an increase of biogas yield from 220 to 445 mL/g VS, during mono and co-digestion, respectively. The co-digestion of VW and CM mixture led to the enhancement of both methane yield and digestate quality in comparison to mono-digestion.
The phosphate fertilizer industry produces highly hazardous and acidic wastewaters. This study wa... more The phosphate fertilizer industry produces highly hazardous and acidic wastewaters. This study was undertaken to develop an integrated approach for the treatment of wastewaters from the phosphate industry. Effluent samples were collected from a local phosphate fertilizer producer and were characterized by their high fluoride and phosphate content. First, the samples were pretreated by precipitation of phosphate and fluoride ions using hydrated lime. The resulting low- fluoride and phosphorus effluent was then treated with the enhanced biological phosphorus removal (EBPR) process to monitor the simultaneous removal of carbon, nitrogen, and phosphorus. Phosphorus removal included a two-stage anaerobic/aerobic system operating under continuous flow. Pretreated wastewater was added to the activated sludge and operated for 160 days in the reactor. The operating strategy included increasing the organic loading rate (OLR) from 0.3 to 1.2 g chemical oxygen demand (COD)/L.d. The stable and high removal rates of COD, NH4(+)-N, and PO4(3-)-P were then recorded. The mean concentrations of the influent were approximately 3600 mg COD/L, 60 mg N/L, and 14 mg P/L, which corresponded to removal efficiencies of approximately 98%, 86%, and 92%, respectively.
A kinetic study of the photocatalytic degradation of 4-chlorophenol employing titanium dioxide is... more A kinetic study of the photocatalytic degradation of 4-chlorophenol employing titanium dioxide is presented. Experiments were carried out in a cylindrical slurry reactor irradiated by UV lamps. The aromatic reaction intermediates were identified and quantified. Intrinsic expressions to represent the kinetics of 4-chlorophenol and the main intermediates, 4-chlorocatechol and hydroquinone, were derived from a proposed reaction scheme. These expressions include
The tanning industry is of great economic importance worldwide; however, the potential environmen... more The tanning industry is of great economic importance worldwide; however, the potential environmental impact of tanning is significant. An important component in tanning is the removal of hair from the hide (unhairing), a process which generates considerable amounts of toxic effluent characterized by a high concentration of sulphur, rich mineral compounds, a high alkalinity and a high organic load. The purpose of the work described here was to evaluate the biodegradability of the unhairing wastewater by endogenous biomass in batch culture and continuous systems. The detoxification of the effluent was assessed by seed germination tests. The batch culture experiments showed that variations in COD, temperature and pH significantly affected the endogenous biomass growth and activity. The optimal treatment condition corresponded to an initial COD of 6 g/L, pH of 7 and 30 degrees C. Under continuous culture conditions, the reactor was fed for 48 days with the unhairing effluent. The optimal COD removal efficiency was 85.5%. During treatment, a transformation of sulphides into thiosulphates and then sulphates was also observed. The effect of untreated and treated unhairing wastewater on seed germination of different plant species was studied. The data suggested that treatment decreased the wastewater toxicity. Indeed, germination was inhibited when the effluent dilution was lower than 20% and 10% for treated and untreated wastewater, respectively.
International Journal of Environmental Science and Technology
The effect of particle size of the organic fraction of municipal solid waste on methane potentiel... more The effect of particle size of the organic fraction of municipal solid waste on methane potentiel was investigated and tested at different substrate-to-inoculum ratios (0.1, 0.5 and 1.0). The highest methane yield was obtained with particle size fraction > 3 mm at S/I of 0.1. Thermo-alkali and thermo-acid methods were also tested as pretreatment to increase the organic matter solubilization and subsequently methane production. The results indicated that maximum variation (63.6%) of soluble chemical oxygen demand was obtained by thermo-acid method. Optimum conditions of thermo-alkali pretreatment were pH 10, time reaction of 30 min and temperature of 105 °C. Soluble chemical oxygen demand and reducing sugar variations reached, respectively, 40 and 69% under these conditions. The methane yield of untreated and thermochemical pretreated OFMSW was determined in batch condition. The highest methane yield (260.9 L/kg VS) was obtained with thermo-alkali pretreatment, which was 21% higher than that of raw substrate. This study may pave a new way for industrial application of dealing with the organic fraction of municipal solid waste.
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