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PROF. NJOROGE BERNARD N. K. CV

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Publications


2014

Njoroge, BNK, N. GA, O. OJP.  2014.  Effects of Water Application Levels on Growth Characteristics and Soil Water Balance of Tomatoes in Greenhouse. International Journal of Engineering Innovation & Research . Volume 3(Issue3):ISSN:2277-5668.

2013

Njoroge, BN, Githere PG.  2013.  Removal of colouration from Textile wastewaters.
Njoroge, BN, Ochieng B, Ngari SK.  2013.  B. Ochieng, S.K. Ngari, B.N.K.Njoroge (no title provided). Abstract

Performance and effectiveness of anaerobic process with biomass recycle, analogous to activated sludge process, in the treatment of high-strength brewery wastewater was investigated. This was achieved by using laboratory bench scale anaerobic digester, at organic loading rate in the range of 0.29 to 10kg Chemical Oxygen Demand (COD) m-3d-1 which was much higher than the theoretical values in the conventional anaerobic process (continuous stirred tank reactor), that ranges between 0.25 to 3.00 kg COD m-3d-1. The study was undertaken using brewery wastewater collected from Thika Brewery Limited in Kenya. The experimental results showered that the recycled process achieved a percentage COD removal of between 86% and 95% while the conventional anaerobic process achieved between 66% and 84% for the same range of volumetric loading rate at a hydraulic retention time (HRT) of 10 days. The recycled process had a shorter start-up time and responded much better to changes in both hydraulic and organic loading rates. Gas production was higher in the recycled process than in the conventional process. The methane yield at standard temperature (20 C) ranged between 0.25 and 0.32 m3/kg COD removed foe the recycled process while it was between 0.19 and 0.30m-3kg COD for conventional process. The experimental result showed that most of the COD removed was converted to methane as opposed to biomass synthesis. This has an added advantage in that there is less sludge production for the recycled process. The results of the study show that anaerobic process with biomass recycle holds potential for treatment of high-strength industrial wastewater, like brewery effluent. Such a process could result in savings, in reduced sludge to be disposed and better effluent than is possible with the conventional anaerobic digestion process.

2012

Njoroge, BNK, Gitau AN, Gakungu NK, Kimani MW.  2012.  Solid Waste Management in Kenya: A case study of Public Technical Institution. ICASTOR Journal of Engineering. Vol. 5( No. 3 (2012) ):127–138.gakungu_paper.pdf

2008

N.K., PROFNJOROGEBERNARD.  2008.  Murigi, Mwangi Peter and B.N.K. Njoroge Efficacy of Polyaluminium Chloride as a substitute for Alum in Water Treatment. University of Nairobi. : Boniface Kavoi, Andrew Makanya, Jameela Hassanali, Hans-Erik Carlsson, Stephen Kiama Abstract
Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} Olfactory acuity differs among animal species depending on age and dependence on smell. However, the attendant functional anatomy has not been elucidated. We sought to determine the functional structure of the olfactory mucosa in suckling and adult dog and sheep. Mucosal samples harvested from ethmoturbinates were analyzed qualitatively and quantitatively. In both species, the olfactory mucosa comprised olfactory, supporting and basal cells, and a lamina propria containing bundles of olfactory cell axons, Bowman’s glands and vascular elements. The olfactory cells terminated apically with an expanded knob, from which cilia projected in a radial fashion from its base and in form of a tuft from its apex in the dog and the sheep respectively. Olfactory cilia per knob weremorenumerous in the dog (19±3) compared to the sheep (7±2) (p < 0.05). In the dog, axonal bundles exhibited one to two centrally located capillaries and the bundles were of greater diameters (73.3±10.3_m) than those of the sheep (50.6±6.8_m), which had no capillaries. From suckling to adulthood in the dog, the packing density of the olfactory and supporting cells increased by 22.5% and 12.6% respectively. Surprisingly in the sheep, the density of the olfactory cells decreased by 26.2% while that of the supportive cells showed no change. Overall epithelial thickness reached 72.5±2.9_m in the dog and 56.8±3.1_m in the sheep. These observations suggest that the mucosa is better structurally refined during maturation in the dog than in the sheep.
N.K., PROFNJOROGEBERNARD.  2008.  Mwangi, Faith Wanjiru and B.N.K. Njoroge, Alternative Solid Waste Management Model for the Nairobi City. University of Nairobi. : Boniface Kavoi, Andrew Makanya, Jameela Hassanali, Hans-Erik Carlsson, Stephen Kiama Abstract
Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} Olfactory acuity differs among animal species depending on age and dependence on smell. However, the attendant functional anatomy has not been elucidated. We sought to determine the functional structure of the olfactory mucosa in suckling and adult dog and sheep. Mucosal samples harvested from ethmoturbinates were analyzed qualitatively and quantitatively. In both species, the olfactory mucosa comprised olfactory, supporting and basal cells, and a lamina propria containing bundles of olfactory cell axons, Bowman’s glands and vascular elements. The olfactory cells terminated apically with an expanded knob, from which cilia projected in a radial fashion from its base and in form of a tuft from its apex in the dog and the sheep respectively. Olfactory cilia per knob weremorenumerous in the dog (19±3) compared to the sheep (7±2) (p < 0.05). In the dog, axonal bundles exhibited one to two centrally located capillaries and the bundles were of greater diameters (73.3±10.3_m) than those of the sheep (50.6±6.8_m), which had no capillaries. From suckling to adulthood in the dog, the packing density of the olfactory and supporting cells increased by 22.5% and 12.6% respectively. Surprisingly in the sheep, the density of the olfactory cells decreased by 26.2% while that of the supportive cells showed no change. Overall epithelial thickness reached 72.5±2.9_m in the dog and 56.8±3.1_m in the sheep. These observations suggest that the mucosa is better structurally refined during maturation in the dog than in the sheep.

2004

2002

M, MRWANJAUDIONYSIUS, N.K. PROFNJOROGEBERNARD.  2002.  Treatment of Textile Wastewater(Synthetic Dye, Congo Red)Using Charcoal. University of Nairobi. : Boniface Kavoi, Andrew Makanya, Jameela Hassanali, Hans-Erik Carlsson, Stephen Kiama
N.K., PROFNJOROGEBERNARD.  2002.  B.N.K.Njoroge and S.G. Mwamachi . University of Nairobi. : Boniface Kavoi, Andrew Makanya, Jameela Hassanali, Hans-Erik Carlsson, Stephen Kiama Abstract
Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} Olfactory acuity differs among animal species depending on age and dependence on smell. However, the attendant functional anatomy has not been elucidated. We sought to determine the functional structure of the olfactory mucosa in suckling and adult dog and sheep. Mucosal samples harvested from ethmoturbinates were analyzed qualitatively and quantitatively. In both species, the olfactory mucosa comprised olfactory, supporting and basal cells, and a lamina propria containing bundles of olfactory cell axons, Bowman’s glands and vascular elements. The olfactory cells terminated apically with an expanded knob, from which cilia projected in a radial fashion from its base and in form of a tuft from its apex in the dog and the sheep respectively. Olfactory cilia per knob weremorenumerous in the dog (19±3) compared to the sheep (7±2) (p < 0.05). In the dog, axonal bundles exhibited one to two centrally located capillaries and the bundles were of greater diameters (73.3±10.3_m) than those of the sheep (50.6±6.8_m), which had no capillaries. From suckling to adulthood in the dog, the packing density of the olfactory and supporting cells increased by 22.5% and 12.6% respectively. Surprisingly in the sheep, the density of the olfactory cells decreased by 26.2% while that of the supportive cells showed no change. Overall epithelial thickness reached 72.5±2.9_m in the dog and 56.8±3.1_m in the sheep. These observations suggest that the mucosa is better structurally refined during maturation in the dog than in the sheep.
N.K., PROFNJOROGEBERNARD.  2002.  B.N.K. Njoroge and J. K. Wairuri . University of Nairobi. : Boniface Kavoi, Andrew Makanya, Jameela Hassanali, Hans-Erik Carlsson, Stephen Kiama Abstract
Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} Olfactory acuity differs among animal species depending on age and dependence on smell. However, the attendant functional anatomy has not been elucidated. We sought to determine the functional structure of the olfactory mucosa in suckling and adult dog and sheep. Mucosal samples harvested from ethmoturbinates were analyzed qualitatively and quantitatively. In both species, the olfactory mucosa comprised olfactory, supporting and basal cells, and a lamina propria containing bundles of olfactory cell axons, Bowman’s glands and vascular elements. The olfactory cells terminated apically with an expanded knob, from which cilia projected in a radial fashion from its base and in form of a tuft from its apex in the dog and the sheep respectively. Olfactory cilia per knob weremorenumerous in the dog (19±3) compared to the sheep (7±2) (p < 0.05). In the dog, axonal bundles exhibited one to two centrally located capillaries and the bundles were of greater diameters (73.3±10.3_m) than those of the sheep (50.6±6.8_m), which had no capillaries. From suckling to adulthood in the dog, the packing density of the olfactory and supporting cells increased by 22.5% and 12.6% respectively. Surprisingly in the sheep, the density of the olfactory cells decreased by 26.2% while that of the supportive cells showed no change. Overall epithelial thickness reached 72.5±2.9_m in the dog and 56.8±3.1_m in the sheep. These observations suggest that the mucosa is better structurally refined during maturation in the dog than in the sheep.
N.K., PROFNJOROGEBERNARD.  2002.  B.N.K.Njoroge and Githere P.G. . University of Nairobi. : Boniface Kavoi, Andrew Makanya, Jameela Hassanali, Hans-Erik Carlsson, Stephen Kiama Abstract
Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} Olfactory acuity differs among animal species depending on age and dependence on smell. However, the attendant functional anatomy has not been elucidated. We sought to determine the functional structure of the olfactory mucosa in suckling and adult dog and sheep. Mucosal samples harvested from ethmoturbinates were analyzed qualitatively and quantitatively. In both species, the olfactory mucosa comprised olfactory, supporting and basal cells, and a lamina propria containing bundles of olfactory cell axons, Bowman’s glands and vascular elements. The olfactory cells terminated apically with an expanded knob, from which cilia projected in a radial fashion from its base and in form of a tuft from its apex in the dog and the sheep respectively. Olfactory cilia per knob weremorenumerous in the dog (19±3) compared to the sheep (7±2) (p < 0.05). In the dog, axonal bundles exhibited one to two centrally located capillaries and the bundles were of greater diameters (73.3±10.3_m) than those of the sheep (50.6±6.8_m), which had no capillaries. From suckling to adulthood in the dog, the packing density of the olfactory and supporting cells increased by 22.5% and 12.6% respectively. Surprisingly in the sheep, the density of the olfactory cells decreased by 26.2% while that of the supportive cells showed no change. Overall epithelial thickness reached 72.5±2.9_m in the dog and 56.8±3.1_m in the sheep. These observations suggest that the mucosa is better structurally refined during maturation in the dog than in the sheep.

2001

M, MRWANJAUDIONYSIUS, N.K. PROFNJOROGEBERNARD.  2001.  Treatment of Daily Wastewater by physical-chemical methods. on Construction Technology (Contec 2001). : Boniface Kavoi, Andrew Makanya, Jameela Hassanali, Hans-Erik Carlsson, Stephen Kiama Abstract
This study investigated the effectiveness of three physical-chemical methods namely; pH adjustment, precipitation with alum and the use of polyelectrolytes. In the treatment of diary wastewater from Brookeside milk processing plant. It also investigated the drainability of the sludge produced by each of the three methods. Laboratory tests were carried out in three different batches, one for each of the three methods. In the alum method enough alum was added to the wastewater samples to cause precipitation by sweep floc. In the pH adjustment method, the pH of samples were lowered to the iso-electric point of the casein proteins of approximately pH 4.5 leading to their precipitation as a result of solubility changes. The polyelectrolytes method involved the use of two polyelectrolytes, Sudfloc 3820 and Sudfloc 3860 each of which was used to coagulate the dirty wastewater. For each of the three methods, the samples were taken in one-litre beakers and subjected to Jar tests to determine the optimum dosages. After one hour of settling the supernatants were decanted and subjected to standard Chemical Oxygen Demand (COD) tests, turbidity and pH measurements. The settled sludge was subjected to drainability studies. Results showed the treatment of dairy wastewater by the three physical-chemical methods to be effective. There were COD removals of between 60% and 90% and turbidity reduction of over 90%. The use of the sudfloc polyelectrolytes was found to be the least demanding in terms of effluent quality control as no pH adjustments of either the wastewater or the effluent was required. The use of polyelectolytes produced the least volumes of sludge and also the better drainability and solids concentration. Sudfloc 3820 was found to achieve better results than Sudfloc 3860 in terms of COD reduction and the drainability of sludge produced although both achieved the same drainability studies. This study showed that each of the three physical-chemical methods can be used effectively to remove the white colour of dairy wastewater as well as the bulk of the proteins and fats, hence, enabling the discharge of the effluents into natural waters to be of good assimilative capacity.
N.K., PROFNJOROGEBERNARD.  2001.  JN Mukabi, BN Njoroge and N Shimizu . on Construction Technology (Contec 2001). : Boniface Kavoi, Andrew Makanya, Jameela Hassanali, Hans-Erik Carlsson, Stephen Kiama Abstract
Performance and effectiveness of anaerobic process with biomass recycle, analogous to activated sludge process, in the treatment of high-strength brewery wastewater was investigated. This was achieved by using laboratory bench scale anaerobic digester, at organic loading rate in the range of 0.29 to 10kg Chemical Oxygen Demand (COD) m-3d-1 which was much higher than the theoretical values in the conventional anaerobic process (continuous stirred tank reactor), that ranges between 0.25 to 3.00 kg COD m-3d-1. The study was undertaken using brewery wastewater collected from Thika Brewery Limited in Kenya. The experimental results showered that the recycled process achieved a percentage COD removal of between 86% and 95% while the conventional anaerobic process achieved between 66% and 84% for the same range of volumetric loading rate at a hydraulic retention time (HRT) of 10 days. The recycled process had a shorter start-up time and responded much better to changes in both hydraulic and organic loading rates. Gas production was higher in the recycled process than in the conventional process. The methane yield at standard temperature (20 C) ranged between 0.25 and 0.32 m3/kg COD removed foe the recycled process while it was between 0.19 and 0.30m-3kg COD for conventional process. The experimental result showed that most of the COD removed was converted to methane as opposed to biomass synthesis. This has an added advantage in that there is less sludge production for the recycled process. The results of the study show that anaerobic process with biomass recycle holds potential for treatment of high-strength industrial wastewater, like brewery effluent. Such a process could result in savings, in reduced sludge to be disposed and better effluent than is possible with the conventional anaerobic digestion process.
N.K., PROFNJOROGEBERNARD.  2001.  J.N.Mukabi, B.N.Njoroge, T.Toda . Proceedings 14 th Road World Congress, Paris. : Boniface Kavoi, Andrew Makanya, Jameela Hassanali, Hans-Erik Carlsson, Stephen Kiama Abstract
Performance and effectiveness of anaerobic process with biomass recycle, analogous to activated sludge process, in the treatment of high-strength brewery wastewater was investigated. This was achieved by using laboratory bench scale anaerobic digester, at organic loading rate in the range of 0.29 to 10kg Chemical Oxygen Demand (COD) m-3d-1 which was much higher than the theoretical values in the conventional anaerobic process (continuous stirred tank reactor), that ranges between 0.25 to 3.00 kg COD m-3d-1. The study was undertaken using brewery wastewater collected from Thika Brewery Limited in Kenya. The experimental results showered that the recycled process achieved a percentage COD removal of between 86% and 95% while the conventional anaerobic process achieved between 66% and 84% for the same range of volumetric loading rate at a hydraulic retention time (HRT) of 10 days. The recycled process had a shorter start-up time and responded much better to changes in both hydraulic and organic loading rates. Gas production was higher in the recycled process than in the conventional process. The methane yield at standard temperature (20 C) ranged between 0.25 and 0.32 m3/kg COD removed foe the recycled process while it was between 0.19 and 0.30m-3kg COD for conventional process. The experimental result showed that most of the COD removed was converted to methane as opposed to biomass synthesis. This has an added advantage in that there is less sludge production for the recycled process. The results of the study show that anaerobic process with biomass recycle holds potential for treatment of high-strength industrial wastewater, like brewery effluent. Such a process could result in savings, in reduced sludge to be disposed and better effluent than is possible with the conventional anaerobic digestion process.
N.K., PROFNJOROGEBERNARD.  2001.  Nancy Macharia, B.N.K.Njoroge, D.M.Wanjau . University of Nairobi. : Boniface Kavoi, Andrew Makanya, Jameela Hassanali, Hans-Erik Carlsson, Stephen Kiama Abstract
Performance and effectiveness of anaerobic process with biomass recycle, analogous to activated sludge process, in the treatment of high-strength brewery wastewater was investigated. This was achieved by using laboratory bench scale anaerobic digester, at organic loading rate in the range of 0.29 to 10kg Chemical Oxygen Demand (COD) m-3d-1 which was much higher than the theoretical values in the conventional anaerobic process (continuous stirred tank reactor), that ranges between 0.25 to 3.00 kg COD m-3d-1. The study was undertaken using brewery wastewater collected from Thika Brewery Limited in Kenya. The experimental results showered that the recycled process achieved a percentage COD removal of between 86% and 95% while the conventional anaerobic process achieved between 66% and 84% for the same range of volumetric loading rate at a hydraulic retention time (HRT) of 10 days. The recycled process had a shorter start-up time and responded much better to changes in both hydraulic and organic loading rates. Gas production was higher in the recycled process than in the conventional process. The methane yield at standard temperature (20 C) ranged between 0.25 and 0.32 m3/kg COD removed foe the recycled process while it was between 0.19 and 0.30m-3kg COD for conventional process. The experimental result showed that most of the COD removed was converted to methane as opposed to biomass synthesis. This has an added advantage in that there is less sludge production for the recycled process. The results of the study show that anaerobic process with biomass recycle holds potential for treatment of high-strength industrial wastewater, like brewery effluent. Such a process could result in savings, in reduced sludge to be disposed and better effluent than is possible with the conventional anaerobic digestion process.
N.K., PROFNJOROGEBERNARD.  2001.  S. M.Njoroge, S.K.Ngari and B.N.K.Njoroge . University of Nairobi. : Boniface Kavoi, Andrew Makanya, Jameela Hassanali, Hans-Erik Carlsson, Stephen Kiama Abstract
Performance and effectiveness of anaerobic process with biomass recycle, analogous to activated sludge process, in the treatment of high-strength brewery wastewater was investigated. This was achieved by using laboratory bench scale anaerobic digester, at organic loading rate in the range of 0.29 to 10kg Chemical Oxygen Demand (COD) m-3d-1 which was much higher than the theoretical values in the conventional anaerobic process (continuous stirred tank reactor), that ranges between 0.25 to 3.00 kg COD m-3d-1. The study was undertaken using brewery wastewater collected from Thika Brewery Limited in Kenya. The experimental results showered that the recycled process achieved a percentage COD removal of between 86% and 95% while the conventional anaerobic process achieved between 66% and 84% for the same range of volumetric loading rate at a hydraulic retention time (HRT) of 10 days. The recycled process had a shorter start-up time and responded much better to changes in both hydraulic and organic loading rates. Gas production was higher in the recycled process than in the conventional process. The methane yield at standard temperature (20 C) ranged between 0.25 and 0.32 m3/kg COD removed foe the recycled process while it was between 0.19 and 0.30m-3kg COD for conventional process. The experimental result showed that most of the COD removed was converted to methane as opposed to biomass synthesis. This has an added advantage in that there is less sludge production for the recycled process. The results of the study show that anaerobic process with biomass recycle holds potential for treatment of high-strength industrial wastewater, like brewery effluent. Such a process could result in savings, in reduced sludge to be disposed and better effluent than is possible with the conventional anaerobic digestion process.
N.K., PROFNJOROGEBERNARD.  2001.  B. Ochieng, S.K. Ngari, B.N.K.Njoroge, . University of Nairobi. : Boniface Kavoi, Andrew Makanya, Jameela Hassanali, Hans-Erik Carlsson, Stephen Kiama Abstract
Performance and effectiveness of anaerobic process with biomass recycle, analogous to activated sludge process, in the treatment of high-strength brewery wastewater was investigated. This was achieved by using laboratory bench scale anaerobic digester, at organic loading rate in the range of 0.29 to 10kg Chemical Oxygen Demand (COD) m-3d-1 which was much higher than the theoretical values in the conventional anaerobic process (continuous stirred tank reactor), that ranges between 0.25 to 3.00 kg COD m-3d-1. The study was undertaken using brewery wastewater collected from Thika Brewery Limited in Kenya. The experimental results showered that the recycled process achieved a percentage COD removal of between 86% and 95% while the conventional anaerobic process achieved between 66% and 84% for the same range of volumetric loading rate at a hydraulic retention time (HRT) of 10 days. The recycled process had a shorter start-up time and responded much better to changes in both hydraulic and organic loading rates. Gas production was higher in the recycled process than in the conventional process. The methane yield at standard temperature (20 C) ranged between 0.25 and 0.32 m3/kg COD removed foe the recycled process while it was between 0.19 and 0.30m-3kg COD for conventional process. The experimental result showed that most of the COD removed was converted to methane as opposed to biomass synthesis. This has an added advantage in that there is less sludge production for the recycled process. The results of the study show that anaerobic process with biomass recycle holds potential for treatment of high-strength industrial wastewater, like brewery effluent. Such a process could result in savings, in reduced sludge to be disposed and better effluent than is possible with the conventional anaerobic digestion process.
N.K., PROFNJOROGEBERNARD.  2001.  D.M.Migwi, B.N.K.Njoroge and D.M.Wanjau . University of Nairobi. : Boniface Kavoi, Andrew Makanya, Jameela Hassanali, Hans-Erik Carlsson, Stephen Kiama Abstract
Performance and effectiveness of anaerobic process with biomass recycle, analogous to activated sludge process, in the treatment of high-strength brewery wastewater was investigated. This was achieved by using laboratory bench scale anaerobic digester, at organic loading rate in the range of 0.29 to 10kg Chemical Oxygen Demand (COD) m-3d-1 which was much higher than the theoretical values in the conventional anaerobic process (continuous stirred tank reactor), that ranges between 0.25 to 3.00 kg COD m-3d-1. The study was undertaken using brewery wastewater collected from Thika Brewery Limited in Kenya. The experimental results showered that the recycled process achieved a percentage COD removal of between 86% and 95% while the conventional anaerobic process achieved between 66% and 84% for the same range of volumetric loading rate at a hydraulic retention time (HRT) of 10 days. The recycled process had a shorter start-up time and responded much better to changes in both hydraulic and organic loading rates. Gas production was higher in the recycled process than in the conventional process. The methane yield at standard temperature (20 C) ranged between 0.25 and 0.32 m3/kg COD removed foe the recycled process while it was between 0.19 and 0.30m-3kg COD for conventional process. The experimental result showed that most of the COD removed was converted to methane as opposed to biomass synthesis. This has an added advantage in that there is less sludge production for the recycled process. The results of the study show that anaerobic process with biomass recycle holds potential for treatment of high-strength industrial wastewater, like brewery effluent. Such a process could result in savings, in reduced sludge to be disposed and better effluent than is possible with the conventional anaerobic digestion process.

1994

N.K., PROFNJOROGEBERNARD.  1994.  Njoroge, Bernard Kimani N.; Robert S. Cherry and William P. Ball . Proceedings of the American Chemical Society Symposium, Division of Environmental Chemistry, San Diego,California,. : Boniface Kavoi, Andrew Makanya, Jameela Hassanali, Hans-Erik Carlsson, Stephen Kiama Abstract
This study investigated the effectiveness of three physical-chemical methods namely; pH adjustment, precipitation with alum and the use of polyelectrolytes. In the treatment of diary wastewater from Brookeside milk processing plant. It also investigated the drainability of the sludge produced by each of the three methods. Laboratory tests were carried out in three different batches, one for each of the three methods. In the alum method enough alum was added to the wastewater samples to cause precipitation by sweep floc. In the pH adjustment method, the pH of samples were lowered to the iso-electric point of the casein proteins of approximately pH 4.5 leading to their precipitation as a result of solubility changes. The polyelectrolytes method involved the use of two polyelectrolytes, Sudfloc 3820 and Sudfloc 3860 each of which was used to coagulate the dirty wastewater. For each of the three methods, the samples were taken in one-litre beakers and subjected to Jar tests to determine the optimum dosages. After one hour of settling the supernatants were decanted and subjected to standard Chemical Oxygen Demand (COD) tests, turbidity and pH measurements. The settled sludge was subjected to drainability studies. Results showed the treatment of dairy wastewater by the three physical-chemical methods to be effective. There were COD removals of between 60% and 90% and turbidity reduction of over 90%. The use of the sudfloc polyelectrolytes was found to be the least demanding in terms of effluent quality control as no pH adjustments of either the wastewater or the effluent was required. The use of polyelectolytes produced the least volumes of sludge and also the better drainability and solids concentration. Sudfloc 3820 was found to achieve better results than Sudfloc 3860 in terms of COD reduction and the drainability of sludge produced although both achieved the same drainability studies. This study showed that each of the three physical-chemical methods can be used effectively to remove the white colour of dairy wastewater as well as the bulk of the proteins and fats, hence, enabling the discharge of the effluents into natural waters to be of good assimilative capacity.
N.K., PROFNJOROGEBERNARD.  1994.  Njoroge, Bernard N. Kimani . on Construction Technology (Contec 2001). : Boniface Kavoi, Andrew Makanya, Jameela Hassanali, Hans-Erik Carlsson, Stephen Kiama Abstract
This study investigated the effectiveness of three physical-chemical methods namely; pH adjustment, precipitation with alum and the use of polyelectrolytes. In the treatment of diary wastewater from Brookeside milk processing plant. It also investigated the drainability of the sludge produced by each of the three methods. Laboratory tests were carried out in three different batches, one for each of the three methods. In the alum method enough alum was added to the wastewater samples to cause precipitation by sweep floc. In the pH adjustment method, the pH of samples were lowered to the iso-electric point of the casein proteins of approximately pH 4.5 leading to their precipitation as a result of solubility changes. The polyelectrolytes method involved the use of two polyelectrolytes, Sudfloc 3820 and Sudfloc 3860 each of which was used to coagulate the dirty wastewater. For each of the three methods, the samples were taken in one-litre beakers and subjected to Jar tests to determine the optimum dosages. After one hour of settling the supernatants were decanted and subjected to standard Chemical Oxygen Demand (COD) tests, turbidity and pH measurements. The settled sludge was subjected to drainability studies. Results showed the treatment of dairy wastewater by the three physical-chemical methods to be effective. There were COD removals of between 60% and 90% and turbidity reduction of over 90%. The use of the sudfloc polyelectrolytes was found to be the least demanding in terms of effluent quality control as no pH adjustments of either the wastewater or the effluent was required. The use of polyelectolytes produced the least volumes of sludge and also the better drainability and solids concentration. Sudfloc 3820 was found to achieve better results than Sudfloc 3860 in terms of COD reduction and the drainability of sludge produced although both achieved the same drainability studies. This study showed that each of the three physical-chemical methods can be used effectively to remove the white colour of dairy wastewater as well as the bulk of the proteins and fats, hence, enabling the discharge of the effluents into natural waters to be of good assimilative capacity.

1986

N.K., PROFNJOROGEBERNARD.  1986.  . Bernard N. Kimani Njoroge, William P. Ball, Robert S. Cherry . Proceedings of the American Chemical Society Symposium, Division of Environmental Chemistry, San Diego,California,. : Boniface Kavoi, Andrew Makanya, Jameela Hassanali, Hans-Erik Carlsson, Stephen Kiama Abstract
This study investigated the effectiveness of three physical-chemical methods namely; pH adjustment, precipitation with alum and the use of polyelectrolytes. In the treatment of diary wastewater from Brookeside milk processing plant. It also investigated the drainability of the sludge produced by each of the three methods. Laboratory tests were carried out in three different batches, one for each of the three methods. In the alum method enough alum was added to the wastewater samples to cause precipitation by sweep floc. In the pH adjustment method, the pH of samples were lowered to the iso-electric point of the casein proteins of approximately pH 4.5 leading to their precipitation as a result of solubility changes. The polyelectrolytes method involved the use of two polyelectrolytes, Sudfloc 3820 and Sudfloc 3860 each of which was used to coagulate the dirty wastewater. For each of the three methods, the samples were taken in one-litre beakers and subjected to Jar tests to determine the optimum dosages. After one hour of settling the supernatants were decanted and subjected to standard Chemical Oxygen Demand (COD) tests, turbidity and pH measurements. The settled sludge was subjected to drainability studies. Results showed the treatment of dairy wastewater by the three physical-chemical methods to be effective. There were COD removals of between 60% and 90% and turbidity reduction of over 90%. The use of the sudfloc polyelectrolytes was found to be the least demanding in terms of effluent quality control as no pH adjustments of either the wastewater or the effluent was required. The use of polyelectolytes produced the least volumes of sludge and also the better drainability and solids concentration. Sudfloc 3820 was found to achieve better results than Sudfloc 3860 in terms of COD reduction and the drainability of sludge produced although both achieved the same drainability studies. This study showed that each of the three physical-chemical methods can be used effectively to remove the white colour of dairy wastewater as well as the bulk of the proteins and fats, hence, enabling the discharge of the effluents into natural waters to be of good assimilative capacity.
N.K., PROFNJOROGEBERNARD.  1986.  Njoroge, B. N. K. . Proceedings of the American Chemical Society Symposium, Division of Environmental Chemistry, San Diego,California,. : Boniface Kavoi, Andrew Makanya, Jameela Hassanali, Hans-Erik Carlsson, Stephen Kiama Abstract
This study investigated the effectiveness of three physical-chemical methods namely; pH adjustment, precipitation with alum and the use of polyelectrolytes. In the treatment of diary wastewater from Brookeside milk processing plant. It also investigated the drainability of the sludge produced by each of the three methods. Laboratory tests were carried out in three different batches, one for each of the three methods. In the alum method enough alum was added to the wastewater samples to cause precipitation by sweep floc. In the pH adjustment method, the pH of samples were lowered to the iso-electric point of the casein proteins of approximately pH 4.5 leading to their precipitation as a result of solubility changes. The polyelectrolytes method involved the use of two polyelectrolytes, Sudfloc 3820 and Sudfloc 3860 each of which was used to coagulate the dirty wastewater. For each of the three methods, the samples were taken in one-litre beakers and subjected to Jar tests to determine the optimum dosages. After one hour of settling the supernatants were decanted and subjected to standard Chemical Oxygen Demand (COD) tests, turbidity and pH measurements. The settled sludge was subjected to drainability studies. Results showed the treatment of dairy wastewater by the three physical-chemical methods to be effective. There were COD removals of between 60% and 90% and turbidity reduction of over 90%. The use of the sudfloc polyelectrolytes was found to be the least demanding in terms of effluent quality control as no pH adjustments of either the wastewater or the effluent was required. The use of polyelectolytes produced the least volumes of sludge and also the better drainability and solids concentration. Sudfloc 3820 was found to achieve better results than Sudfloc 3860 in terms of COD reduction and the drainability of sludge produced although both achieved the same drainability studies. This study showed that each of the three physical-chemical methods can be used effectively to remove the white colour of dairy wastewater as well as the bulk of the proteins and fats, hence, enabling the discharge of the effluents into natural waters to be of good assimilative capacity.

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