Pub Date : 2012-01-18DOI: 10.2174/1874829501205010001
G. Esposito, L. Frunzo, F. Liotta, A. Panico, F. Pirozzi
Bio-methane potential (BMP) tests are widely used in studies concerning the anaerobic digestion of organic solids. Although they are often criticized to be time consumer, with an average length longer than 30 days, such tests are doubtless easy to be conducted, relatively inexpensive and repeatable. Moreover, BMP tests give significant information about the bio-methanation of specific substrates and provide experimental results essential to calibrate and validate mathematical models. These last two aspects have been handled in this work where the following elements have been de- scribed in detail: i) the methods used to conduct the BMP tests; ii) the cumulative bio-methane curves obtained from three BMP tests, concerning respectively two pure organic substrates (swine manure-SM and greengrocery waste-GW) and an organic substrate obtained by mixing buffalo manure (BM) and maize silage (MS); iii) the procedure used to calibrate a mathematical model proposed by the authors to simulate the anaerobic digestion process; iv) the results of the calibration process. This paper shows that BMP tests are extremely helpful to determine the amount of bio-methane obtainable from different organic solids and under different operational conditions as well as the biodegradability of the investigated sub- strate, the relative specific rate of bio-methanation and the synergic effect of multiple co-digested substrates. Furthermore BMP tests represent an interesting tool for the technical and economical optimization of bio-methane producing plants.
{"title":"Bio-methane potential tests to measure the biogas production from the digestion and co-digestion of complex organic substrates.","authors":"G. Esposito, L. Frunzo, F. Liotta, A. Panico, F. Pirozzi","doi":"10.2174/1874829501205010001","DOIUrl":"https://doi.org/10.2174/1874829501205010001","url":null,"abstract":"Bio-methane potential (BMP) tests are widely used in studies concerning the anaerobic digestion of organic solids. Although they are often criticized to be time consumer, with an average length longer than 30 days, such tests are doubtless easy to be conducted, relatively inexpensive and repeatable. Moreover, BMP tests give significant information about the bio-methanation of specific substrates and provide experimental results essential to calibrate and validate mathematical models. These last two aspects have been handled in this work where the following elements have been de- scribed in detail: i) the methods used to conduct the BMP tests; ii) the cumulative bio-methane curves obtained from three BMP tests, concerning respectively two pure organic substrates (swine manure-SM and greengrocery waste-GW) and an organic substrate obtained by mixing buffalo manure (BM) and maize silage (MS); iii) the procedure used to calibrate a mathematical model proposed by the authors to simulate the anaerobic digestion process; iv) the results of the calibration process. This paper shows that BMP tests are extremely helpful to determine the amount of bio-methane obtainable from different organic solids and under different operational conditions as well as the biodegradability of the investigated sub- strate, the relative specific rate of bio-methanation and the synergic effect of multiple co-digested substrates. Furthermore BMP tests represent an interesting tool for the technical and economical optimization of bio-methane producing plants.","PeriodicalId":344616,"journal":{"name":"The Open Environmental Engineering Journal","volume":"109 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-01-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126137191","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-12-30DOI: 10.2174/1874829501104010190
A. Kavadia, D. Vayenas, S. Pavlou, G. Aggelis
The dynamics of a model of a free-living nitrogen-fixing population, grown in a chemostat alone or in competition with a non-nitrogen-fixing population, was studied through bifurcation analysis. It is demonstrated that the ability of the nitrogen-fixing population to survive depends on the ammonia and carbon source concentrations and the kinetics parameters of the system. Under competitive conditions the nitrogen-fixing population, characterized by low growth rates, can survive alone at stable steady state only at low dilution rate values. Especially, there is a threshold of the dilution rate above which only the competitive population can survive. When amensalistic interactions are established, coexistence of both populations is favored. At low dilution rate values the survival of the nitrogen-fixing population alone is restricted while this population can survive at higher ammonia concentrations either in coexistence state or in multistability state together with the competitive population. When nitrogen-fixing population successfully inhibits its competitor, then its survival is enhanced towards the coexistence state.
{"title":"Dynamics of a Free-Living Nitrogen-Fixing Bacteria Population Lacking of Competitive Advantage Towards an Antagonistic Population","authors":"A. Kavadia, D. Vayenas, S. Pavlou, G. Aggelis","doi":"10.2174/1874829501104010190","DOIUrl":"https://doi.org/10.2174/1874829501104010190","url":null,"abstract":"The dynamics of a model of a free-living nitrogen-fixing population, grown in a chemostat alone or in competition with a non-nitrogen-fixing population, was studied through bifurcation analysis. It is demonstrated that the ability of the nitrogen-fixing population to survive depends on the ammonia and carbon source concentrations and the kinetics parameters of the system. Under competitive conditions the nitrogen-fixing population, characterized by low growth rates, can survive alone at stable steady state only at low dilution rate values. Especially, there is a threshold of the dilution rate above which only the competitive population can survive. When amensalistic interactions are established, coexistence of both populations is favored. At low dilution rate values the survival of the nitrogen-fixing population alone is restricted while this population can survive at higher ammonia concentrations either in coexistence state or in multistability state together with the competitive population. When nitrogen-fixing population successfully inhibits its competitor, then its survival is enhanced towards the coexistence state.","PeriodicalId":344616,"journal":{"name":"The Open Environmental Engineering Journal","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130990360","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-11-21DOI: 10.2174/1874829501104010181
Jan Stenis, M. Romanov, W. Hogland
An overview of the classification of ecological normalization methods is presented to facilitate the evaluationof alternatives. An historical review is given of the development of several ecologica ...
概述了生态归一化方法的分类，以方便评估备选方案。对几种生态系统的发展进行了历史回顾。
{"title":"Analysis and classification of the modern methods of ecological normalization of anthropogenic load : Russia vs. the West","authors":"Jan Stenis, M. Romanov, W. Hogland","doi":"10.2174/1874829501104010181","DOIUrl":"https://doi.org/10.2174/1874829501104010181","url":null,"abstract":"An overview of the classification of ecological normalization methods is presented to facilitate the evaluationof alternatives. An historical review is given of the development of several ecologica ...","PeriodicalId":344616,"journal":{"name":"The Open Environmental Engineering Journal","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130203127","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-11-16DOI: 10.2174/1874829501104010170
I. Nhapi, N. Banadda, R. Murenzi, C. Sekomo, U. Wali
Heavy metals are widely used in textile industries and significant losses occur during the manufacture and processing of textiles, and these lost heavy metals are discharged in the effluent. Adsorption of heavy metals is a new technology for treatment of wastewater containing different types of selected heavy metals. In this study, adsorbents Carbonized Rice Husk (CRH) and Activated Rice Husk (ARH) made out of rice husks, available as agriculture waste, are investigated as viable materials for treatment of Pb, Cd, Cu, and Zn containing industrial wastewater at controlled pH. The results obtained from the batch experiments revealed a relative ability of the rice husk in removing some heavy metals at pH 7. One hand one, the CRH adsorption capacity decreases in the order of Cu > Pb > Zn > Cd in batch adsorption whereas during Rapid Small Scale Column Tests the adsorption capacity decrease as follow Cu> Zn> Pb> Cd. On the other hand, ARH adsorption capacity performance is similar to CRH. However, during Rapid Small Scale Column Tests the adsorption capacity decreases in the order Zn>Cu>Pb>Cd. The kinetic removal in batch experiment shows that the net uptake of Pb, Cd, Cu, Zn was 54.3%, 8.24%, 51.4% and 56.7%, respectively whereas using CRH, while it varied as 74.04%, 43.4%, 70.08% and 77.2% for the same dosages of ARH. Therefore, it is concluded that as regards to CRH, ARH demonstrated higher potential to remove relatively all selected heavy metals.
{"title":"Removal of Heavy Metals from Industrial Wastewater Using Rice Husks","authors":"I. Nhapi, N. Banadda, R. Murenzi, C. Sekomo, U. Wali","doi":"10.2174/1874829501104010170","DOIUrl":"https://doi.org/10.2174/1874829501104010170","url":null,"abstract":"Heavy metals are widely used in textile industries and significant losses occur during the manufacture and processing of textiles, and these lost heavy metals are discharged in the effluent. Adsorption of heavy metals is a new technology for treatment of wastewater containing different types of selected heavy metals. In this study, adsorbents Carbonized Rice Husk (CRH) and Activated Rice Husk (ARH) made out of rice husks, available as agriculture waste, are investigated as viable materials for treatment of Pb, Cd, Cu, and Zn containing industrial wastewater at controlled pH. The results obtained from the batch experiments revealed a relative ability of the rice husk in removing some heavy metals at pH 7. One hand one, the CRH adsorption capacity decreases in the order of Cu > Pb > Zn > Cd in batch adsorption whereas during Rapid Small Scale Column Tests the adsorption capacity decrease as follow Cu> Zn> Pb> Cd. On the other hand, ARH adsorption capacity performance is similar to CRH. However, during Rapid Small Scale Column Tests the adsorption capacity decreases in the order Zn>Cu>Pb>Cd. The kinetic removal in batch experiment shows that the net uptake of Pb, Cd, Cu, Zn was 54.3%, 8.24%, 51.4% and 56.7%, respectively whereas using CRH, while it varied as 74.04%, 43.4%, 70.08% and 77.2% for the same dosages of ARH. Therefore, it is concluded that as regards to CRH, ARH demonstrated higher potential to remove relatively all selected heavy metals.","PeriodicalId":344616,"journal":{"name":"The Open Environmental Engineering Journal","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114541947","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-09-23DOI: 10.2174/1874829501104010156
D. Ogoyi, C. Mwita, E. Nguu, P. Shiundu
Lake Victoria, which is the largest fresh water lake in Africa, represents a unique ecosystem that has the largest fresh water fishery in the continent. However, increased anthropogenic activities has increased the potential pollution of the lake especially the heavy metal pollutants which may be toxic to humans and aquatic fauna. There is need therefore for continuous monitoring of pollution levels in the lake. Samples of water, soil sediments and algae were collected in dry, long and short rainy periods of 2008 and analyzed for heavy metal by Atomic Absorption Spectrophotometry. The highest concentration of trace metals were found in sediment samples with Zn having the highest mean concentration values in both Winam (1.019 ppm) and Mwanza gulf (0.889 ppm). The mean concentration of Pb was higher in water samples from Winam gulf (0.823 ppm), while Hg in microalgae samples from Winam gulf had a mean concentration of 0.000148 ppm. The highest concentration of Zn (1.589 ppm) was determined in the sediment samples from Kirumba bay of the Mwanza gulf and the lowest was in sediments from Kishimba bay (0.327 ppm). Levels of trace metals in microalgae were not significant in different sites of the Mwanza Gulf. Like in the Mwanza gulf, levels of Zn was high in sediments from all the sites sampled in Winam Gulf, the highest recorded at Kisat. Pb levels were highest in the water samples from Hippo point, whereas concentration levels of Cd, Cr and Hg were lowest in all the four sites sampled. The maximum biomass of micro- algae occurred at Kisat during the short rain season (November-December) followed by Kamito in the same season.
{"title":"Determination of Heavy Metal Content in Water, Sediment and Microalgae from Lake Victoria, East Africa","authors":"D. Ogoyi, C. Mwita, E. Nguu, P. Shiundu","doi":"10.2174/1874829501104010156","DOIUrl":"https://doi.org/10.2174/1874829501104010156","url":null,"abstract":"Lake Victoria, which is the largest fresh water lake in Africa, represents a unique ecosystem that has the largest fresh water fishery in the continent. However, increased anthropogenic activities has increased the potential pollution of the lake especially the heavy metal pollutants which may be toxic to humans and aquatic fauna. There is need therefore for continuous monitoring of pollution levels in the lake. Samples of water, soil sediments and algae were collected in dry, long and short rainy periods of 2008 and analyzed for heavy metal by Atomic Absorption Spectrophotometry. The highest concentration of trace metals were found in sediment samples with Zn having the highest mean concentration values in both Winam (1.019 ppm) and Mwanza gulf (0.889 ppm). The mean concentration of Pb was higher in water samples from Winam gulf (0.823 ppm), while Hg in microalgae samples from Winam gulf had a mean concentration of 0.000148 ppm. The highest concentration of Zn (1.589 ppm) was determined in the sediment samples from Kirumba bay of the Mwanza gulf and the lowest was in sediments from Kishimba bay (0.327 ppm). Levels of trace metals in microalgae were not significant in different sites of the Mwanza Gulf. Like in the Mwanza gulf, levels of Zn was high in sediments from all the sites sampled in Winam Gulf, the highest recorded at Kisat. Pb levels were highest in the water samples from Hippo point, whereas concentration levels of Cd, Cr and Hg were lowest in all the four sites sampled. The maximum biomass of micro- algae occurred at Kisat during the short rain season (November-December) followed by Kamito in the same season.","PeriodicalId":344616,"journal":{"name":"The Open Environmental Engineering Journal","volume":"377 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132166122","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-09-23DOI: 10.2174/1874829501104010162
K. Kotut, Victor G. Nganga, F. Kariuki
In recent years concerns over dwindling reserves of ground water and overloaded or costly sewage treatment plants has generated much interest in the reuse or recycling of greywater. Re-use of greywater offers several advantages including a reduction in the demand on potable water supplies. Despite the prevalent direct reuse of greywater, especially in water scarce areas, its quality is not well documented. This study determined the physico-chemical and microbial quality of greywater produced by households in Homa Bay town. Most of greywater generated had a higher electrical conductivity and salinity and lower concentration of dissolved oxygen. Greywater pH values varied widely but were mostly higher than that of clean water. Biological oxygen demand varied widely (410-6250 mg L -1 ). Total coliform (TC) counts in greywater samples ranged from 1.3 to 7.6 colony forming units (CFU)/ 100 mL while fecal coliform (FC) counts varied between 3000 and 7.4 million CFU/ 100 mL. Field observations showed that the variation in TC and FC counts resulted from differences in the level of households' personal hygiene, difference in the intensity of greywater reuse and duration of storage. Among the potentially pathogenic bacteria investigated, Salmonella was the most frequent, occurring in 31% of all the greywater samples collected. Vibrio occurred in the least number of samples (9%). The study concludes that greywater produced is most likely to be contaminated by pathogenic bacteria and should therefore be disinfected prior to reuse.
{"title":"Physico-Chemical and Microbial Quality of Greywater from Various Households in Homa Bay Town","authors":"K. Kotut, Victor G. Nganga, F. Kariuki","doi":"10.2174/1874829501104010162","DOIUrl":"https://doi.org/10.2174/1874829501104010162","url":null,"abstract":"In recent years concerns over dwindling reserves of ground water and overloaded or costly sewage treatment plants has generated much interest in the reuse or recycling of greywater. Re-use of greywater offers several advantages including a reduction in the demand on potable water supplies. Despite the prevalent direct reuse of greywater, especially in water scarce areas, its quality is not well documented. This study determined the physico-chemical and microbial quality of greywater produced by households in Homa Bay town. Most of greywater generated had a higher electrical conductivity and salinity and lower concentration of dissolved oxygen. Greywater pH values varied widely but were mostly higher than that of clean water. Biological oxygen demand varied widely (410-6250 mg L -1 ). Total coliform (TC) counts in greywater samples ranged from 1.3 to 7.6 colony forming units (CFU)/ 100 mL while fecal coliform (FC) counts varied between 3000 and 7.4 million CFU/ 100 mL. Field observations showed that the variation in TC and FC counts resulted from differences in the level of households' personal hygiene, difference in the intensity of greywater reuse and duration of storage. Among the potentially pathogenic bacteria investigated, Salmonella was the most frequent, occurring in 31% of all the greywater samples collected. Vibrio occurred in the least number of samples (9%). The study concludes that greywater produced is most likely to be contaminated by pathogenic bacteria and should therefore be disinfected prior to reuse.","PeriodicalId":344616,"journal":{"name":"The Open Environmental Engineering Journal","volume":"66 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123608962","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-09-22DOI: 10.2174/1874829501104010133
A. Makokha, Leonard R. Mghweno, H. Magoha, Amina Nakajugo, John M. Wekesa
In this paper, a study was conducted to determine lead contamination levels in the environment (soil and water) and foods. The foods targeted were maize, beans and fish which are among the major staple foods common to Kenya, Tanzania and Uganda. Water, food and soil samples were taken in 2007 and 2009. The study sites were located in Kisumu (Kenya), Mwanza (Tanzania), and Kampala (Uganda). From the results of 2009, the mean lead content in tap water, was within the WHO maximum safe limits of 1.0 � g/100 ml for all the samples from the three cities. For all water samples ob- tained from similar sources from the three cities, the lead content during 2007 was significantly higher than that of 2009. For the soil samples from Kisumu and Kampala the lead content in the 2009 samples was significantly lower (p< 0.05) than that of samples from similar sources during 2007, indicating a decreasing trend of lead pollution in soil in the two cit- ies. In 2009 in all the three cities, the mean lead content in all the maize and bean samples was below the WHO maximum limits of 20.0 � g/100 g. For the maize the lead content in 2009 was significantly lower (p< 0.05) than that of 2007. The mean lead content in all the fish samples was below the WHO maximum limits of 20.0 � g/100 g in 2009. For all similar fish samples from the three cities, the lead content in the samples of 2009 was significantly lower than that of the samples of 2007. The results indicate that for all the samples of food, tap water and soil from the three cities, the lead content was within the WHO maximum levels in 2009, and showed a decreasing trend from 2007 to 2009.
{"title":"The Effects of Environmental Lead Pollution in Kisumu, Mwanza and Kampala","authors":"A. Makokha, Leonard R. Mghweno, H. Magoha, Amina Nakajugo, John M. Wekesa","doi":"10.2174/1874829501104010133","DOIUrl":"https://doi.org/10.2174/1874829501104010133","url":null,"abstract":"In this paper, a study was conducted to determine lead contamination levels in the environment (soil and water) and foods. The foods targeted were maize, beans and fish which are among the major staple foods common to Kenya, Tanzania and Uganda. Water, food and soil samples were taken in 2007 and 2009. The study sites were located in Kisumu (Kenya), Mwanza (Tanzania), and Kampala (Uganda). From the results of 2009, the mean lead content in tap water, was within the WHO maximum safe limits of 1.0 � g/100 ml for all the samples from the three cities. For all water samples ob- tained from similar sources from the three cities, the lead content during 2007 was significantly higher than that of 2009. For the soil samples from Kisumu and Kampala the lead content in the 2009 samples was significantly lower (p< 0.05) than that of samples from similar sources during 2007, indicating a decreasing trend of lead pollution in soil in the two cit- ies. In 2009 in all the three cities, the mean lead content in all the maize and bean samples was below the WHO maximum limits of 20.0 � g/100 g. For the maize the lead content in 2009 was significantly lower (p< 0.05) than that of 2007. The mean lead content in all the fish samples was below the WHO maximum limits of 20.0 � g/100 g in 2009. For all similar fish samples from the three cities, the lead content in the samples of 2009 was significantly lower than that of the samples of 2007. The results indicate that for all the samples of food, tap water and soil from the three cities, the lead content was within the WHO maximum levels in 2009, and showed a decreasing trend from 2007 to 2009.","PeriodicalId":344616,"journal":{"name":"The Open Environmental Engineering Journal","volume":"163 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116267747","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-09-22DOI: 10.2174/1874829501104010147
N. R. Kulabako, N. K. Ssonko, J. Kinobe
This study was undertaken to create an understanding of greywater characteristics and to demonstrate a low cost reuse option involving application of small tower gardens for Greywater treatment and reuse in a peri-urban settlement, Kawaala in Kampala city, Uganda. To realise this, field surveys, greywater and soil sampling and analysis and, tower garden installation at selected households were undertaken. The common sources of greywater in Kawaala were found to be kitchen, bathroom and laundry with the majority of the households (72%) pouring laundry water in open drains and spaces adjacent to their homes. The greywater generated in the area exhibited high BOD5 (71-873 mgL -1 ) and COD (140-4886 mgL -1 ) and E.Coli (<0-13900 cfu per 100 mL) values necessitating treatment prior to disposal in the environment. The greywater had low average BOD5/COD ratio (<0.5) meaning that it is not easily treatable by biological means. Greywater application to the tower gardens, had limited impact on the soil potassium, organic matter and nitrogen content but increased the phosphorus content. The vegetables grown in the greywater towers thrived but were attacked by pests necessitating pest control. The households with the tower gardens appreciated the simplicity of the technology. To create demand for it requires sensitization and social marketing within the community. There is need to determine the hydraulic load of a tower garden to guide the number and size for a particular quantity of generated greywater for optimum performance. Also further monitoring is needed to ascertain the vegetable yield per soil volume, impact on crop growth and people's livelihoods.
{"title":"Greywater Characteristics and Reuse in Tower Gardens in Peri-Urban Areas - Experiences of Kawaala, Kampala, Uganda","authors":"N. R. Kulabako, N. K. Ssonko, J. Kinobe","doi":"10.2174/1874829501104010147","DOIUrl":"https://doi.org/10.2174/1874829501104010147","url":null,"abstract":"This study was undertaken to create an understanding of greywater characteristics and to demonstrate a low cost reuse option involving application of small tower gardens for Greywater treatment and reuse in a peri-urban settlement, Kawaala in Kampala city, Uganda. To realise this, field surveys, greywater and soil sampling and analysis and, tower garden installation at selected households were undertaken. The common sources of greywater in Kawaala were found to be kitchen, bathroom and laundry with the majority of the households (72%) pouring laundry water in open drains and spaces adjacent to their homes. The greywater generated in the area exhibited high BOD5 (71-873 mgL -1 ) and COD (140-4886 mgL -1 ) and E.Coli (<0-13900 cfu per 100 mL) values necessitating treatment prior to disposal in the environment. The greywater had low average BOD5/COD ratio (<0.5) meaning that it is not easily treatable by biological means. Greywater application to the tower gardens, had limited impact on the soil potassium, organic matter and nitrogen content but increased the phosphorus content. The vegetables grown in the greywater towers thrived but were attacked by pests necessitating pest control. The households with the tower gardens appreciated the simplicity of the technology. To create demand for it requires sensitization and social marketing within the community. There is need to determine the hydraulic load of a tower garden to guide the number and size for a particular quantity of generated greywater for optimum performance. Also further monitoring is needed to ascertain the vegetable yield per soil volume, impact on crop growth and people's livelihoods.","PeriodicalId":344616,"journal":{"name":"The Open Environmental Engineering Journal","volume":"125 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127115714","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-09-22DOI: 10.2174/1874829501104010124
U. Wali, I. Nhapi, A. Ngombwa, N. Banadda, H. Nsengimana, R. Kimwaga, I. Nansubuga
In this paper, we to assess the level of pollution in the Akagera Transboundary River. The followings parame- ters namely NH4-N, NO3-N, PO4-P, Total Dissolved Solids (TDS), conductivity, pH, Temperature, and Turbidity were identified and quantified. Sampling was conducted a monthly basis from March 2008 to February 2009 at eleven sampling points on the Akagera River system. The landuse and land form characteristics were studied using satellite imagery and ground truthing. From this pollution reduction factors in terms of kg/ha.yr of pollution load were developed for each lan- duse type and used for developing the model. Rainfall and river flow data were obtained from gauging stations in and around the river. Water quality parameters particularly values of NH3-N changed from 0 to 2.36 mg/l, NO3-N from 1.8 mg/l to 314.4 mg/l and PO4-P from 0.02 mg/l to 19.3 mg/l. Field observations supported with computed export coefficient values showed that bare soils are the most influencing negative factor on water quality in the Akagera River.
{"title":"Modelling of Nonpoint Source Pollution in Akagera Transboundary River in Rwanda","authors":"U. Wali, I. Nhapi, A. Ngombwa, N. Banadda, H. Nsengimana, R. Kimwaga, I. Nansubuga","doi":"10.2174/1874829501104010124","DOIUrl":"https://doi.org/10.2174/1874829501104010124","url":null,"abstract":"In this paper, we to assess the level of pollution in the Akagera Transboundary River. The followings parame- ters namely NH4-N, NO3-N, PO4-P, Total Dissolved Solids (TDS), conductivity, pH, Temperature, and Turbidity were identified and quantified. Sampling was conducted a monthly basis from March 2008 to February 2009 at eleven sampling points on the Akagera River system. The landuse and land form characteristics were studied using satellite imagery and ground truthing. From this pollution reduction factors in terms of kg/ha.yr of pollution load were developed for each lan- duse type and used for developing the model. Rainfall and river flow data were obtained from gauging stations in and around the river. Water quality parameters particularly values of NH3-N changed from 0 to 2.36 mg/l, NO3-N from 1.8 mg/l to 314.4 mg/l and PO4-P from 0.02 mg/l to 19.3 mg/l. Field observations supported with computed export coefficient values showed that bare soils are the most influencing negative factor on water quality in the Akagera River.","PeriodicalId":344616,"journal":{"name":"The Open Environmental Engineering Journal","volume":"293 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132278703","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-09-22DOI: 10.2174/1874829501104010141
C. Tungaraza, R. Chibunda, A. Pereka
Gold extraction by artisan miners in different parts of Tanzania is widely done by mercury amalgamation tech- nique. To the people living in and around the mining cites there is a potential for exposure to contamination through con- sumption of Hg contaminated food stuffs. Current studies on estimates of dietary human exposure to mercury in these ar- eas have been limited to contributions of Hg contaminated fish consumption centrally to WHO recommendation on the use of Total Diet Studies. In this study dietary Hg intake of people at Mugusu gold mining village was determined by us- ing a total diet study approach. Results indicate that 37 types of foods are consumed in this Village. Rice, maize, tubers and fish were the most consumed food categories with an average daily consumption of 134, 270, 113 and 97 g per person per day, respectively. The fish category contained the highest average content of total Hg (0.16 � g g -1 wet weight). The calculated average dietary intake of Hg was 41.05 � g/day, which is 2.6 times higher than the daily intake recommended by FAO/WHO (15.5 � g/day) for protection of the foetus and young children. It is therefore concluded that the current to- tal dietary intake of Hg in the studied area is at risk level to young children born to women living in this village. It is therefore recommended that, mercury intake in artisanal gold mining settlements should be monitored regularly.
在坦桑尼亚的不同地区，手工采矿者普遍采用汞汞合并技术来提取黄金。对于居住在采矿城市及其周围的人来说，通过食用受汞污染的食物，有可能暴露于污染中。目前关于这些地区人类膳食汞暴露估计的研究仅限于食用受汞污染的鱼类对世卫组织关于使用总饮食研究的建议的影响。本研究采用全饮食研究方法测定木谷苏金矿村居民膳食汞摄入量。结果表明，该村消费的食品有37种。水稻、玉米、块茎和鱼类是食用最多的食物类别，人均日食用量分别为134、270、113和97克。鱼类总汞平均含量最高(湿重0.16 μ g g -1)。计算得出的平均膳食汞摄入量为41.05 g/d，比粮农组织/世界卫生组织为保护胎儿和幼儿推荐的每日摄入量(15.5 g/d)高2.6倍。因此，我们得出结论，研究地区目前的汞摄入量对居住在该村的妇女所生的幼儿处于危险水平。因此，建议定期监测手工采金定居点的汞摄入量。
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