542,440 research outputs found
Comparative study on functional and structural properties of the Barbary sheep and European mouflon haemoglobins
No full text
Anaerobic treatment of slaughterhouse wastewater using the UASB process
No full textEffluents from the slaughterhouses, meat and poultry industries are heavily polluted and contain a high concentration of biodegradable organic materials. Therefore, the pollution capacity of these industries is high. Most of these industries discharge their effluents to a sewer or a watercourse.In order to comply with water pollution control standards and to reduce costs on sewer surcharges, these industries have to apply an adequate treatment of their effluents.Physical and chemical treatment methods as well as the conventional biological treatment processes are frequently applied in the treatment of these effluents. A combination of the methods are required where the effluent is to be discharged to surface waters, since no single treatment method will provide sufficient effluent.In the last decade, the high rate anaerobic wastewater treatment systems have become a good alternative for conventional aerobic as well as anaerobic biological treatment methods. The high rate anaerobic treatment systems were initially developed for the treatment of highly soluble low and medium strength wastewaters. These systems provided only a partial treatment of complex wastewaters containing a high fraction of suspended solids such as slaughterhouse wastewater.Investigations have shifted towards the application of high rate systems like the upflow anaerobic sludge blanket (UASB) for the complete treatment of agro-industrial wastewaters which are more difficult to handle, because they contain relatively high concentrations of suspended solids, i.e. complex wastewaters.Presently, the UASB system is the most widely applied high rate anaerobic system for complete treatment of such complex wastes.This thesis focuses on the question whether, and under which operationa conditions and environmental circumstances a one stage UASB mesophilic anaerobic treatment system is suitable for a complete treatment of slaughterhouse wastewater in practice.The feasibility of using the upflow flocculent anaerobic sludge blanket (UASB) process for a one stage anaerobic treatment of unsettled complex slaughterhouse wastewater, which contains approximately 50% of coarse insoluble COD, was investigated (Chapter 2). The continuous experiments were performed in a 25.3 m 3UASB pilot-plant which was operated under semi-continuous conditions, viz. with a varying organic load over day and nighttime (i.e. high organic load during the daytime and with low organic load at night) and with weekend feed interruptions. The UASB pilot-plant was operated at a temperature of 30° C. In order to assess the feasibility of the process under conditions of lower temperatures the temperature was reduced to 20°C, 20 weeks after the start-up of the reactor.The data indicated that the system can satisfactorily handle organic loads up to 3.5 kg COD m -3day -1at a liquid retention time of 8 h at temperatures as low as 20°C. Temporary shock loads up to 7.5 kg COD m -3day -1during the day time at a liquid retention time of 5 h were accommodated satisfactorily provided such a shock load was followed by a period of low loading, e.g. at night.A significant discrepancy was found between the treatment efficiency in terms of COD reduction and to the lower calculated percentage of supplied COD total converted into methane-COD. This difference indicated that a significant portion of the achieved COD reduction was due to the accumulation of non- or slowly biodegradable substrate ingredients in the reactor. No differentiations could be made between the different types of substrate ingredients that accummulated in the reactor because the accumulated sludge was not characterized. However, a part of the accumulated substrate was converted to CH 4 in periods of feed interruptions.In Chapter 3 the feasibility of the upflow granular anaerobic sludge blanket process for a one-stage anaerobic treatment of slaughterhouse wastewater was investigated. The experiments were performed under semi-continuous operational conditions viz. continuous feeding at a constant organic load (24 h day) during the working days but with weekend feed interruptions, and process temperatures of 30°C and 20°C. Under a stable operation of the system, i.e. at a maximum COD reduction and a high conversion of COD into methane, the optimal loading rates that could be applied were 11 kg COD m -3day -1and 7 kg COD m -3day -1at 30°C and at 20°C respectively.The system was less effective in the removal of coarse suspended solids, compared to the removal of the colloidal and soluble fractions from the slaughterhouse wastewater.The data obtained in these investigations indicate that imposed prolonged loadings exceed the optimal loading rates, lead to deterioration of the specific methanogenic activity of the sludge, due to the accumulation of colloidal and soluble fractions of the wastewater in the sludge bed. Therefore, it was concluded that the system stability strongly depends on the processes involved in the removal of the colloidal and soluble compounds from the wastewater and their conversion into methane. As the predominant - non-biological-mechanisms underlying the elimination of these wastewaters pollutants were considered the entrapment and the adsorption mechanisms. The effect of these mechanisms on the rate of the liquefaction of the accumulated substrate - which is the required first step in their conversion into methane - were discussed.The different pollutant fractions of the wastewater, viz. the coarse suspended solids, the colloidal and the soluble compounds affect the performance of the UASB reactors because of the different mechanisms involved in the removal of these substrate ingredients and their subsequent conversion into methane. Therefore, these mechanisms were investigated in more detail. The results of these investigations are presented in Chapter 4. The experiments were performed in a one-stage flocculent sludge UASB-reactor under continuous operational conditions viz. continuous feeding at a constant organic load during 24 h a day and 7 days a week.The COD removal efficiency of the UASB reactor exceeded the COD removal efficiency as expected from the observed CH 4 production, indicating once again that non-biological mechanisms are involved. Two different non-biological mechanisms were distinguished in the removal of substrate ingredients from the wastewater. The entrapment mechanism prevailed in the elimination of coarse suspended solids, while mainly adsorption mechanisms are involved in the removal of colloidal and the soluble fractions of the wastewater.A continued accumulation of substrate ingredients in the reactor ultimately will become detrimental for the stability of the anaerobic treatment process, as it leads to sludge flotation and consequently could result in a complete loss of the active biomass from the reactor.After having demonstrated the principle feasibility of the upflow anaerobic sludge blanket (UASB) process for a one-stage anaerobic treatment of the slaughterhouse wastewater, we decided to assess the maximum possible extent of anaerobic degradation of the soluble, colloidal and coarse suspended solids fractions of the slaughterhouse wastewater (Chapter 5). In this way we intended to get a better insight in the real limitations of the system. All the experiments were performed at process temperatures of 30°C and 20°C, using membrane filtered wastewater (wastewater mf ), paper filtered wastewater (wastewater pf ) and total wastewater. The experiments were performed in a recirculated batch digester system with granular sludge. The experiments with the coarse suspended solids separated from the wastewater were performed with granular sludge as well as with flocculent sludge using conventional batch-fed stirred digesters. The maximum biodegrability percentages (i.e. conversion into methane) found at 30°C were 75% for wastewater mf , 61% for wastewater pf and 67% for wastewater total while at 20°C these values were 72%, 49% and 51% respectively. The maximum biodegrability of the coarse suspended solids fraction of the waste amounts to 50% at 30°C and 45% at 20°C.The mechanisms involved in the removal of the soluble and colloidal fractions of the slaughterhouse wastewater were thoroughly studied and elucidated. The data obtained in these experiments indicate that the prevailing mechanism in the removal of the soluble but especially also the colloidal fraction of the wastewater is an adsorption mechanism. The relatively high degree of adsorption of the colloidal fraction of the wastewater to the surface of the sludge, in combination with its high fat content, will deteriorate the specific methanogenic activity of the sludge. The adsorption of the colloidal materials will ultimately result in an enclosure of the granular sludge bacterial matter with a film of increasing thickness, and perhaps also density, which increasingly will hamper the supply of substrate to the bacteria present in the grains. The deterioration effect of fats towards the methanogenic activity of the sludge was explained on the basis of the inhibitory effect of the long-chain fatty acids of the neutral fats.As the extent of adsorption is very similar at lower and higher temperatures, but the rate of liquefaction of adsorbed compounds drops significantly at decreasing temperatures, it will be evident that the process can withstand considerably lower loading rates at 20°C as compared to 30°C.Therefore, it is concluded that the rate of liquefaction of the adsorbed insoluble colloidal fraction of the wastewater is the controlling factor with respect to loading potentials of the process and consequently that the temperature is the factor of predominant importance
Anaerobic treatment of slaughterhouse wastewater using the UASB process
No full textEffluents from the slaughterhouses, meat and poultry industries are heavily polluted and contain a high concentration of biodegradable organic materials. Therefore, the pollution capacity of these industries is high. Most of these industries discharge their effluents to a sewer or a watercourse.In order to comply with water pollution control standards and to reduce costs on sewer surcharges, these industries have to apply an adequate treatment of their effluents.Physical and chemical treatment methods as well as the conventional biological treatment processes are frequently applied in the treatment of these effluents. A combination of the methods are required where the effluent is to be discharged to surface waters, since no single treatment method will provide sufficient effluent.In the last decade, the high rate anaerobic wastewater treatment systems have become a good alternative for conventional aerobic as well as anaerobic biological treatment methods. The high rate anaerobic treatment systems were initially developed for the treatment of highly soluble low and medium strength wastewaters. These systems provided only a partial treatment of complex wastewaters containing a high fraction of suspended solids such as slaughterhouse wastewater.Investigations have shifted towards the application of high rate systems like the upflow anaerobic sludge blanket (UASB) for the complete treatment of agro-industrial wastewaters which are more difficult to handle, because they contain relatively high concentrations of suspended solids, i.e. complex wastewaters.Presently, the UASB system is the most widely applied high rate anaerobic system for complete treatment of such complex wastes.This thesis focuses on the question whether, and under which operationa conditions and environmental circumstances a one stage UASB mesophilic anaerobic treatment system is suitable for a complete treatment of slaughterhouse wastewater in practice.The feasibility of using the upflow flocculent anaerobic sludge blanket (UASB) process for a one stage anaerobic treatment of unsettled complex slaughterhouse wastewater, which contains approximately 50% of coarse insoluble COD, was investigated (Chapter 2). The continuous experiments were performed in a 25.3 m 3UASB pilot-plant which was operated under semi-continuous conditions, viz. with a varying organic load over day and nighttime (i.e. high organic load during the daytime and with low organic load at night) and with weekend feed interruptions. The UASB pilot-plant was operated at a temperature of 30° C. In order to assess the feasibility of the process under conditions of lower temperatures the temperature was reduced to 20°C, 20 weeks after the start-up of the reactor.The data indicated that the system can satisfactorily handle organic loads up to 3.5 kg COD m -3day -1at a liquid retention time of 8 h at temperatures as low as 20°C. Temporary shock loads up to 7.5 kg COD m -3day -1during the day time at a liquid retention time of 5 h were accommodated satisfactorily provided such a shock load was followed by a period of low loading, e.g. at night.A significant discrepancy was found between the treatment efficiency in terms of COD reduction and to the lower calculated percentage of supplied COD total converted into methane-COD. This difference indicated that a significant portion of the achieved COD reduction was due to the accumulation of non- or slowly biodegradable substrate ingredients in the reactor. No differentiations could be made between the different types of substrate ingredients that accummulated in the reactor because the accumulated sludge was not characterized. However, a part of the accumulated substrate was converted to CH 4 in periods of feed interruptions.In Chapter 3 the feasibility of the upflow granular anaerobic sludge blanket process for a one-stage anaerobic treatment of slaughterhouse wastewater was investigated. The experiments were performed under semi-continuous operational conditions viz. continuous feeding at a constant organic load (24 h day) during the working days but with weekend feed interruptions, and process temperatures of 30°C and 20°C. Under a stable operation of the system, i.e. at a maximum COD reduction and a high conversion of COD into methane, the optimal loading rates that could be applied were 11 kg COD m -3day -1and 7 kg COD m -3day -1at 30°C and at 20°C respectively.The system was less effective in the removal of coarse suspended solids, compared to the removal of the colloidal and soluble fractions from the slaughterhouse wastewater.The data obtained in these investigations indicate that imposed prolonged loadings exceed the optimal loading rates, lead to deterioration of the specific methanogenic activity of the sludge, due to the accumulation of colloidal and soluble fractions of the wastewater in the sludge bed. Therefore, it was concluded that the system stability strongly depends on the processes involved in the removal of the colloidal and soluble compounds from the wastewater and their conversion into methane. As the predominant - non-biological-mechanisms underlying the elimination of these wastewaters pollutants were considered the entrapment and the adsorption mechanisms. The effect of these mechanisms on the rate of the liquefaction of the accumulated substrate - which is the required first step in their conversion into methane - were discussed.The different pollutant fractions of the wastewater, viz. the coarse suspended solids, the colloidal and the soluble compounds affect the performance of the UASB reactors because of the different mechanisms involved in the removal of these substrate ingredients and their subsequent conversion into methane. Therefore, these mechanisms were investigated in more detail. The results of these investigations are presented in Chapter 4. The experiments were performed in a one-stage flocculent sludge UASB-reactor under continuous operational conditions viz. continuous feeding at a constant organic load during 24 h a day and 7 days a week.The COD removal efficiency of the UASB reactor exceeded the COD removal efficiency as expected from the observed CH 4 production, indicating once again that non-biological mechanisms are involved. Two different non-biological mechanisms were distinguished in the removal of substrate ingredients from the wastewater. The entrapment mechanism prevailed in the elimination of coarse suspended solids, while mainly adsorption mechanisms are involved in the removal of colloidal and the soluble fractions of the wastewater.A continued accumulation of substrate ingredients in the reactor ultimately will become detrimental for the stability of the anaerobic treatment process, as it leads to sludge flotation and consequently could result in a complete loss of the active biomass from the reactor.After having demonstrated the principle feasibility of the upflow anaerobic sludge blanket (UASB) process for a one-stage anaerobic treatment of the slaughterhouse wastewater, we decided to assess the maximum possible extent of anaerobic degradation of the soluble, colloidal and coarse suspended solids fractions of the slaughterhouse wastewater (Chapter 5). In this way we intended to get a better insight in the real limitations of the system. All the experiments were performed at process temperatures of 30°C and 20°C, using membrane filtered wastewater (wastewater mf ), paper filtered wastewater (wastewater pf ) and total wastewater. The experiments were performed in a recirculated batch digester system with granular sludge. The experiments with the coarse suspended solids separated from the wastewater were performed with granular sludge as well as with flocculent sludge using conventional batch-fed stirred digesters. The maximum biodegrability percentages (i.e. conversion into methane) found at 30°C were 75% for wastewater mf , 61% for wastewater pf and 67% for wastewater total while at 20°C these values were 72%, 49% and 51% respectively. The maximum biodegrability of the coarse suspended solids fraction of the waste amounts to 50% at 30°C and 45% at 20°C.The mechanisms involved in the removal of the soluble and colloidal fractions of the slaughterhouse wastewater were thoroughly studied and elucidated. The data obtained in these experiments indicate that the prevailing mechanism in the removal of the soluble but especially also the colloidal fraction of the wastewater is an adsorption mechanism. The relatively high degree of adsorption of the colloidal fraction of the wastewater to the surface of the sludge, in combination with its high fat content, will deteriorate the specific methanogenic activity of the sludge. The adsorption of the colloidal materials will ultimately result in an enclosure of the granular sludge bacterial matter with a film of increasing thickness, and perhaps also density, which increasingly will hamper the supply of substrate to the bacteria present in the grains. The deterioration effect of fats towards the methanogenic activity of the sludge was explained on the basis of the inhibitory effect of the long-chain fatty acids of the neutral fats.As the extent of adsorption is very similar at lower and higher temperatures, but the rate of liquefaction of adsorbed compounds drops significantly at decreasing temperatures, it will be evident that the process can withstand considerably lower loading rates at 20°C as compared to 30°C.Therefore, it is concluded that the rate of liquefaction of the adsorbed insoluble colloidal fraction of the wastewater is the controlling factor with respect to loading potentials of the process and consequently that the temperature is the factor of predominant importance
Recent seismicity and realistic waveforms modeling to reduce the ambiguities about the 1303 seismic activity in Egypt
No full textConservation in an Islamic context a case study of Makkah
No full textThe Holy Qu’ rān contains many injunctions for Muslims to respect and conserve the natural environment but few address the built environment. Habitat at the time of the Prophet (PBOH) was in the vernacular and relatively impermanent. The first habitat was the cave, the second the tent and then simple flat roofed buildings of post and lintel construction made of mud and rubble. Later buildings were not indigenous but reflected the architectural styles and techniques of Muslim pilgrims from beyond the Arabian Peninsula. Permanent exotic buildings were later erected as reminders of holy places and events. This work advances a case to restore and preserve historic and religious sites in Makkah, Saudi Arabia. Makkah is the destination for millions of Muslim pilgrims who annually pay homage to Allah during the occasions of Hajj, Ramadan and Umra. The tranquillity and peaceful ambience that one associates with the holiest of Islamic experiences have, over the years, given way to jostling crowds of people who must be expediently housed, fed, transported, and protected. Due to the lack of planning and the insensitive but profitable development of the city, Makkah is in grave danger of becoming a bustling metropolis instead of a sanctuary where pilgrims gather to perform their religious rites and reaffirm their dedication to Allah. The author calls for professional planning and international cooperation to guide future development for this expanding and sensitive area. The author's ideas are grounded in practical and aesthetic study, therefore, the political, environmental and economic issues are examined in relationship to religious, historic and artistic values. The author makes proposals for a future Makkah that would provide pilgrims with the physical comforts, security, and serene environment they deserve—without destroying the city they came to visit. The author discusses preservation and conservation in the western world and the need for their acceptance in Muslim countries, the former being an aesthetic and intellectual concept sustained by law and the latter being the prescribed free expression of the individual unhindered by material considerations. Both worlds are rapidly being overwhelmed by materialism, but body, mind and spirit combine in making us aware of our surroundings and the way in what we see around us has come into being
Microalga, Acutodesmus obliquus KGE 30 as a potential candidate for CO2 mitigation and biodiesel production
No full textIn this study, the effect of flue gas CO2 on growth, lipid production, and fatty acid composition of a green microalga Acutodesmus obliquus KGE 30 was investigated. The highest growth rate (0.46 g L-1 and mu(max) = 1.09 day(-1)), total inorganic carbon removal (95.9 mg L-1), and lipid productivity (20.1 mg L-1 day L-1) was obtained at 14.1 % CO2 after 4 days of cultivation. In a semicontinuous batch reactor, the highest biomass production (1.19 g L-1) was achieved after 12 days with continuous injection of flue gas CO2. Compared with synthetic CO2, fatty acid methyl ester analysis showed that the amount of unsaturated fatty acid increased by 19.2 % with 14.1 % flue gas CO2. The application of flue gas CO2 improved biomass production and lipid productivity in A. obliquus. The current investigation demonstrated that the use of flue gas CO2 could reduce the cost of microalgae biomass production for better biofuel generation.The project was financially supported by the Korea Institute of Science and Technology (Grant 2E26300) and the Ministry of Trade, Industry & Energy (industrial infrastructure program for fundamental technologies (N0000885)
Reproductive and productive performance of rabbit does submitted to an oral glucose supplementation
No full textIn order to investigate the effect of different levels of oral glucose supplementation and/or reproductive method on productive
and reproductive performance of New Zealand White (NZW) doe rabbits in the tropic, 36 bucks and 120 doe NZW rabbits were
equally divided among four treatment groups (n59 bucks130 does). The treatments consisted of supplementing drinking
water with 0 (control), 2.5, 5 and 10 g glucose/l, respectively. To study the effect of reproduction method (natural v. artificial),
each group was divided into two sub-groups (naturally mated and artificially inseminated) with the same bucks of the same
treatment group. Glucose supplementation at 5 or 10 g/l of water increased ( P,0.01) litter weight at birth and at weaning,
and litter weight gain during the 4 weeks. However, glucose supplementation at 2.5 or 5.0 g/l water decreased ( P,0.01)
feed consumption from 7 to 14 days after delivery. Glucose supplementation at 2.5 g/l water did not affect productive and
reproductive performance of rabbits. Artificially inseminated does had higher daily litter weight gain between 21 and 28 days
post partum. Artificially inseminated group had better milk conversion during the 1st and 4th week as compared to naturally
mated groups. Compared with the control group, the economic efficiency and performance index of NZW rabbits was
significantly improved by 5 g glucose supplementation under tropic condition
Towards a sterile insect technique field release of <it>Anopheles arabiensis </it>mosquitoes in Sudan: Irradiation, transportation, and field cage experimentation
No full textAbstract Background The work described in this article forms part of a study to suppress a population of the malaria vector Anopheles arabiensis in Northern State, Sudan, with the Sterile Insect Technique. No data have previously been collected on the irradiation and transportation of anopheline mosquitoes in Africa, and the first series of attempts to do this in Sudan are reported here. In addition, experiments in a large field cage under near-natural conditions are described. Methods Mosquitoes were irradiated in Khartoum and transported as adults by air to the field site earmarked for future releases (400 km from the laboratory). The field cage was prepared for experiments by creating resting sites with favourable conditions. The mating and survival of (irradiated) laboratory males and field-collected males was studied in the field cage, and two small-scale competition experiments were performed. Results Minor problems were experienced with the irradiation of insects, mostly associated with the absence of a rearing facility in close proximity to the irradiation source. The small-scale transportation of adult mosquitoes to the release site resulted in minimal mortality ( Conclusion It is concluded that although conditions are challenging, there are no major obstacles associated with the small-scale irradiation and transportation of insects in the current setting. The field cage is suitable for experiments and studies to test the competitiveness of irradiated males can be pursued. The scaling up of procedures to accommodate much larger numbers of insects needed for a release is the next challenge and recommendations to further implementation of this genetic control strategy are presented.</p
g) Suppression d'une des arcades de l'aqueduc
No full textFarnall Harry, Sayed Metoualli, Verrucci Ernesto, Sayyed Ahmad el-. g) Suppression d'une des arcades de l'aqueduc. In: Comité de Conservation des Monuments de l'Art Arabe. Fascicule 33, exercice 1920-1924, 1928. pp. 374-375
- …
