Department of Biological and Environmental Sciences

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Student learning impact on science teachers’ teaching: The case of a form 3 science case in Kenya .
(201) Nashon, SM.; Anderson, D.; Okemwa, P.; Kelonye, Festus.; Ooko, Selline.; Ombogo, Peterson.
This paper reports on the study that investigated the following question: How do Kenyan science teachers perceive the impact of students’ contextualized science learning on their pedagogy, roles and Views about previously modeled pedagogy in an integrated classroom-local Jua Kali curriculum unit? A case study approach in which narrative and teacher change were respectively employed as methodological and analytical frameworks revealed that the teachers: 1) gained an increased awareness of and understood better their students’ science learning abilities that allowed them to take increased responsibility for own learning, 2) developed and accepted new understanding of their teaching roles, and 3) became more critical of how science pedagogy was modeled for them as students and continuing practitioners.
Species abundance, food preference and nutritive value of goat diets in the semi-arid lands of east-central Kenya
(ILRI, 1996) Osolo, N.K.; Kinuthia, J.N.; Gachuiri, C.K.; Okeyo, A.M.; Wanyoike, M.M.; Okomo, M.
The key forage species and nutrient composition of forage species preferred by free-ranging East African goats in rangelands of eastern-central Kenya were determined. One hundred and five forage species were identified including 30 tree, 29 shrub, 20 grass and 25 forb species. Shrubs and short trees were the most preferred forage species and thus formed the bulk of the goat diets. Ironically the forage species most preferred by the goats were not necessarily the most abundant on the ground, indicating that ease of accessibility and palatability may be important determinants for choice of a forage specie. That grasses and forbs were the least preferred could be largely explained by the fact that goats are naturally browsers.
Community participation in afforestation and agroforestry programmes in kenya: the influence of biophysical environmental in the case of Teso district
(2000) Ekisa, Tom George
On global scale, community participation in various activities is the core in the quest for sustainable development and environmental protection related issues. Community involvement in tree planting in Kenya is as old as modern agroforestry that started in 1971. However, certain biophysical environmental factors have not worked against the concept of community participation in tree planting. Although deforestation and resultant problems such as woodfuel shortage and reduced other forest based products, climate change, and soil erosion, have occurred world-wide, the worst hit areas are in developing countries of the Sub-Saharan Africa. Teso District falls in this region and therefore not an exception; the district inhabitants encounter these environmental problems. The study revealed that both biophysical environmental factors were major disincentives to community participation in tree planting. Among the biophysical aspects, soil and landscape characteristics, and entomological incidences were quite significant. However, the study also discovered that water availability and pathological factors were not significant obstacles to tree planting in the district
Analysis of manual and centralised supervisory control operations to improve level of service: a case study of pyramid hill no 1 channel, Victoria, Australia
(Kluwer Academic Publishers, 2001-02) Malano, Hector M.; Mutua, Benedict M.
The current challenge facing irrigation inAustralia is tofind ways to improve the operationalperformance of existing systems rather thanconstructing new ones. Unsteady flowsimulation models are often used as keytools to study and test improvedoperational scenarios for existing systems.While these models are generally notrecommended for real-time control, researchhas shown that they are able to simulatecanal response for different test scenariosfor operations planning. This paperpresents the results of two alternativemodes of operation for the Pyramid Hill No.1 Channel in northern Victoria, Australia.The channel is currently under manualoperation. Centralised control is the mostimmediate option considered by theirrigation authority to enable remotesupervision and control of the canal toimprove the channel operation and level ofservice standards. This type of control istermed Supervisory Control and DataAcquisition (SCADA). The two alternativeoperational scenarios were simulated andanalysed using the unsteady flow-simulationmodel DUFLOW. Specific performanceindicators were defined to compare the twomodes of operations based on the simulationresults. The results show that SCADAoperation has considerable potential toclosely match the discharges at thedownstream regulator with those ordered byfarmers while maintaining the water surfaceelevations within allowable fluctuationtolerance throughout the length of thecanal.
Characterization of -soluble n-ethylmaleimide–sensitive fusion attachment protein in alveolar type ii cells implications in lung surfactant secretion
(2002) Abonyo, B. O.; Wang, Pengcheng; Narasaraju, Telugu A.; Rowan III, William H.; Zimmerman, Un-Jin; Lin Liu
N-ethylmaleimide–sensitive fusion protein (NSF) and soluble NSF attachment protein (α-SNAP) are thought to be soluble factors that transiently bind and disassemble SNAP receptor complex during exocytosis in neuronal and endocrine cells. Lung surfactant is secreted via exocytosis of lamellar bodies from alveolar epithelial type II cells. However, the secretion of lung surfactant is a relatively slow process, and involvement of SNAP receptor and its cofactors (NSF and α-SNAP) in this process has not been demonstrated. In this study, we investigated a possible role of α-SNAP in surfactant secretion. α-SNAP was predominantly associated with the membranes in alveolar type II cells as determined by Western blot and immunocytochemical analysis using confocal microscope. Membrane-associated α-SNAP was not released from the membrane fraction when the cells were lyzed in the presence of Ca2+ or Mg2+ATP. The alkaline condition (0.1 M Na2CO3, pH 12), known to extract peripheral membrane proteins also failed to release it from the membrane. Phase separation using Triton X-114 showed that α-SNAP partitioned into both aqueous and detergent phases. NSF had membrane-bound characteristics similar to α-SNAP in type II cells. Permeabilization of type II cells with β-escin resulted in a partial loss of α-SNAP from the cells, but cellular NSF was relatively unchanged. Addition of exogenous α-SNAP to the permeabilized cells increased surfactant secretion in a dose-dependent manner, whereas exogenous NSF has much less effects. An α-SNAP antisense oligonucleotide decreased its protein level and inhibited surfactant secretion. Our results suggest a role of α-SNAP in lung surfactant secretion.
Reorganization of cytoskeleton during surfactant secretion in lung type II cells: a role of annexin II
(Elsevier, 2003) Singh, Taran K.; Abonyo, B. O.; Narasaraju, Telugu A.
The secretion of lung surfactant requires the movement of lamellar bodies to the plasma membrane through cytoskeletal barrier at the cell cortex. We hypothesized that the cortical cytoskeleton undergoes a transient disassembly/reassembly in the stimulated type II cells, therefore allowing lamellar bodies access to the plasma membrane. Stabilization of cytoskeleton with Jasplakinolinde (JAS), a cell permeable actin microfilament stabilizer, caused a dose-dependent inhibition of lung surfactant secretion stimulated by terbutaline. This inhibition was also observed in ATP-, phorbol 12-myristate 13-acetate (PMA)- or Ca2 + ionophore A23187-stimulated surfactant secretion. Stimulation of type II cells with terbutaline exhibited a transient disassembly of filamentous actin (F-actin) as determined by staining with Oregon Green 488 Phalloidin. The protein kinase A inhibitor, H89, abolished the terbutaline-induced F-actin disassembly. Western blot analysis using anti-actin and anti-annexin II antibodies showed a transient increase of G-actin and annexin II in the Triton X-100 soluble fraction of terbutaline-stimulated type II cells. Furthermore, introduction of exogenous annexin II tetramer (AIIt) into permeabilized type II cells caused a disruption in the cortical actin. Treatment of type II cells with N-ethylmaleimide (NEM) resulted in a disruption of the cortical actin. NEM also inhibited annexin II’s abilities to bundle F-actin. The results suggest that cytoskeleton undergoes reorganization in the stimulated type II cells, and annexin II tetramer plays a role in this process. D 2003 Elsevier Inc. All rights reserved.
Soil erosion management at a large catchment scale using the RUSLE-GIS: the case of Masinga catchment, Kenya
(WIT Press, 2004-08-23) Mutua, Benedict M.; Klik, A.
Kenya is one country suffering heavily from land degradation due to increasing anthropogenic pressure on its natural resources. As is common to many tropical countries, Kenya suffers from a lack of financial resources to research, monitor and model sources and outcomes of environmental degradation for large catchment domains. In order to evaluate viable management options, soil erosion modelling at the catchment scale needs to be undertaken. This paper presents a comprehensive methodology that integrates an erosion model, the Revised Universal Soil Loss Equation (RUSLE) with a Geographic Information System (GIS) for estimating soil erosion at Masinga catchment, which is a typical rural catchment in Kenya. The objective of the study was to map the spatial mean annual soil erosion for the Masinga catchment and identify the risk erosion areas. Current land use/cover and management practices and selected, feasible, future management practices were evaluated to determine their effects on average annual soil loss. The results can be used to advice the catchment stakeholders in prioritising the areas of immediate erosion mitigation. The integrated approach allows for relatively easy, fast, and cost-effective estimation of spatially distributed soil erosion and sediment delivery. It thus provides a useful and efficient tool for predicting long-term soil erosion potential and assessing erosion impacts of various cropping systems and conservation support practices.
Autoregulation of ccl26 synthesis and secretion in a549 cells: a possible mechanism by which alveolar epithelial cells modulate airway inflammation
(2005) Abonyo, B. O.; Alexander, M. S. Alexander; Heiman, A. S.
Abonyo, B. O., M. S. Alexander, and A. S. Heiman. Autoregulation of CCL26 synthesis and secretion in A549 cells: a possible mechanism by which alveolar epithelial cells modulate airway inflammation. Am J Physiol Lung Cell Mol Physiol 289: L478 –L488, 2005. First published April 29, 2005; doi:10.1152/ajplung.00032.2005.— Eotaxins (CCL11, CCL24, CCL26) originating from airway epithelial cells and leukocytes have been detected in bronchoalveolar lavage of asthmatics. Although the alveolar epithelium is the destination of uncleared allergens and other inflammatory products, scanty information exists on their contribution to the generation and regulation of the eotaxins. We envisioned a state whereby alveolar type II cells, a known source of other inflammatory proteins, could be involved in both the production and regulation of CCL24 and CCL26. Herein, we demonstrated that all three eotaxins are constitutively expressed in A549 cells. IL-4 and IL-13 stimulated a concentration-dependent secretion of CCL24 and CCL26. The cytokines did not act synergistically. Cycloheximide and actinomycin D abrogated IL-4- and IL13-dependent CCL26 but not CCL24 secretion. Both IL-13 and IL-4 stimulated CCL26 synthesis that was inhibited in a concentrationdependent manner by CCL26 but not CCL24. Only CCL26 reduced expression of CCR3 receptors by 30 – 40%. On the other hand, anti-CCR3 pretreatment reduced IL-4 IL-13-dependent CCL26 secretion, implying autoregulation. A CCR3-specific antagonist (SB328437) significantly decreased IL-4-dependent synthesis and release of CCL26. Eosinophils treated with medium from IL-4-stimulated A549 cells preincubated with anti-CCL26 showed a marked decrease of superoxide anion production compared with anti-CCL24 treated. These results suggest that CCL26 is a major eotaxin synthesized and released by alveolar epithelial cells and is involved in autoregulation of CCR3 receptors and other eotaxins. This CCL26-CCR3 ligandreceptor system may be an attractive target for development of therapeutics that limits progress of inflammation in airway disease
Cytokine-stimulated human lung alveolar epithelial cells release eotaxin-2 (CCL24) and eotaxin-3 (CCL26)
(Mary Ann Liebert, Inc, 2005) Heiman, Ann S.; Abonyo, B. O.; Darling-Reed, Selina F.; Alexander, Marilyn S.
Asthma is a complex inflammatory disease characterized by a prolonged underlying airway inflammation resulting from cytokine-orchestrated signaling between many types of cells, including airway epithelial cells. Trafficking, recruitment, and activation of cells in airway disease are, in part, modulated by the newly discovered CC subfamily of chemokines, eotaxin (CCL11), eotaxin-2 (CCL24) and eotaxin-3 (CCL26), which transduce signals by acting as agonists for the CCR3 receptor. The specific cytokine stimuli that modulate CCL24 and CCL26 release in airway epithelial cells remain poorly defined. Thus, human 549 alveolar type II epithelium-like cells were stimulated singly and with combinations of 1–100 ng/ml tumor necrosis-factor- (TNF- ), interleukin-1 (IL-1), and IL-4, cytokines known to be elevated in the airways of asthmatics. Release of CCL11, CCL24, and CCL26 was quantified by ELISA, and CCR3 receptors monitored by immunocytochemistry and FACS analysis. Results suggest that epithelial cells release CCL11 during the first 24 h of stimulation, in contrast to a significant increase in CCL24 and CCL26 release after 24–48 h of stimulation. Differential release of the eotaxins in response to cytokine combinations was noted. The alveolar type II epithelial cells were found to possess constitutive CCR3 receptors, which increased after proinflammatory cytokine stimulation. The airway epithelium CCR3 receptor/eotaxin ligand signal transduction system may be an important target for development of novel mechanism-based adjunctive therapies designed to interrupt the underlying chronic inflammation in allergic and inflammatory disorders.
Predictings sediment loading into Masinga reservoir and its storage capacity reduction
(2005-09-07) Mutua, Benedict M.; Klik, Andreas; Loiskandl, Willibald
It is estimated that the annual loss in storage capacity of the world’s reservoirs due to sedimentation is around 0.5 – 1.0%. For many reservoirs, however, annual depletion rates are much higher and can go up to 4% or 5%, such that they lose the majority of their capacity after only 25 – 30 years. The Masinga reservoir, one of the main reservoirs in Kenya, designed for hydropower generation, public water supply and irrigation is faced with severe sedimentation. The designed sediment load into this reservoir in 1981 was estimated to be 3.0 x 106 m3 per year (about 1% per annum reservoir reduction). By 2000, annual sediment loading had increased to over 11.0 x 106 m3 , nearly four times, thus reducing the designed capacity by more than 15%. As land degradation has become more evident with increasing land use change within Masinga catchment over the years, the operation and life span of Masinga reservoir is thus under imminent danger from erosion and sedimentation. There is need therefore to quantify spatially soil erosion and sediment yield reaching the reservoir with a view to reducing the sediment delivery. In this paper, a comprehensive procedure to predict spatial sediment yield and overall mean annual sediment volume delivered to Masinga reservoir is presented. Geographical Information System (GIS) technology as a tool to support soil erosion and sediment models is employed. Simulations of different land use and management scenarios are performed and their corresponding sediment yields estimated. Predictions show annual sediment loading into the reservoir of about 14.0 x 106 m3 for land use practices in 2003. By simulating the best feasible management practices (BMPs), the achieved results show that the sediment volume reaching the reservoir could be reduced to about 6.0 x 106 m3 per year.
Estimating spatial sediment delivery ratio on a large rural catchment
(2006-05-20) Mutua, Benedict M.; Klik, A.
Soil erosion and sediment yield from catchments are key limitations to achieving sustainable land use and maintaining water quality in streams, lakes and other water bodies. Controlling sediment loading requires the knowledge of the soil erosion and sedimentation. However, sediment yield is usually not available as a direct measurement but estimated by using a sediment delivery ratio (SDR). An accurate prediction of SDR is important in controlling sediments for sustainable natural resources development and environmental protection. There is no precise procedure to estimate SDR, although the USDA has published a handbook in which the SDR is related to drainage area. This paper presents a new approach for estimating spatial sediment delivery ratio (SDR) for large rural catchments. The SDR is predicted using a Hillslope Sediment Distributed Delivery (HSDD) model in conjunction with a physically distributed hydrological model in a GIS environment. The new approach was developed and tested on Masinga catchment, a rural large catchment in Kenya. The hydrological model was validated using predicted and observed daily stream flows and a performance criterion based on Nash Sutcliffe coefficient of model efficiency was used. The developed model is not only conceptually easy and well suited to the local data needs but also requires less parameters, which offer less uncertainty in its application while meeting the intended purpose.
Modelling soil erosion and sediment yield at a catchment scale: the case of Masinga catchment, Kenya
(John Wiley & Sons, Ltd., 2006-08-07) Mutua, Benedict M.; Klik, A.; Loiskandl, w.
Development of improved soil erosion and sediment yield prediction technology is required to provide catchment stakeholders with the tools they need to evaluate the impact of various management strategies on soil loss and sediment yield in order to plan for the optimal use of the land. In this paper, a newly developed approach is presented to predict the sources of sediment reaching the stream network within Masinga, a large‐scale rural catchment in Kenya. The study applies the revised universal soil loss equation (RUSLE) and a developed hillslope sediment delivery distributed (HSDD) model embedded in a geographical information system (GIS). The HSDD model estimates the sediment delivery ratio (SDR) on a cell‐by‐cell basis using the concept of runoff travel time as a function of catchment characteristics. The model performance was verified by comparing predicted and measured plot runoff and sediment yield. The results show a fairly good relationship between predicted and measured sediment yield (R2=0·82). The predicted results show that the developed modelling approach can be used as a major tool to estimate spatial soil erosion and sediment yield at a catchment scale. Copyright © 2006 John Wiley & Sons, Ltd.
Modulation of eotaxin-3 (CCL26) in alveolar type II epithelial cells
(2007)
Airway epithelial inflammation associated with emphysema, chronic bronchitis, chronic obstructive pulmonary disease (COPD) and asthma is regulated in part by alveolar type II cell chemokine signaling. Data suggest that resident lung cells use CCR3, CCR5 and CCR2 chemokine receptor/ligand systems to regulate the profile of leukocytes recruited in disease-associated inflammatory conditions. Thus studies were designed to test whether alveolar type II cells possess a Th1-activated CCR5-ligand system that modulates the Th2-activated CCR3/eotaxin-2 (CCL24), eotaxin-3 (CCL26) chemokine systems. The A549 alveolar type II epithelial-like cell culture model was used to demonstrate that alveolar type II cells constitutively express CCR5 which may be upregulated by MIP-1alpha (CCL3) whose expression was induced by the Th1 cytokines IL-1beta and IFN-gamma. Selective down-regulation of CCL26, but not CCL24, was observed in CCL3 and IL-4/CCL3 stimulated cells. Down-regulation was reversed by anti-CCR5 neutralizing antibody treatment. Thus, one mechanism through which Th1-activated CCCR5/ligand pathways modulate Th2-activated CCR3/ligand pathways is the differential down-regulation of CCL26 expression. Results suggest that the CCR3 and CCR5 receptor/ligand signaling pathways may be important targets for development of novel mechanism-based adjunctive therapies designed to abrogate the chronic inflammation associated with airway diseases.
Post-transcriptional silencing of CCR3 downregulates IL-4 stimulated release of eotaxin-3 (CCL26) and other CCR3 ligands in alveolar type II cells
(2008) Taka, Equar; Errahali, Younes J.; Abonyo, B. O.; Heiman, Ann S.
Trafficking and inflammation in airway diseases are, in part, modulated by members of the CC chemokine family, eotaxin-1 (CCL11), eotaxin-2 (CCL24), and eotaxin-3 (CCL26), which transduce signals through their CCR3 receptor. In this context, we hypothesized that transfecting alveolar type II epithelial cells with CCR3-targeted siRNA or antisense (AS-ODN) sequences will downregulate cellular synthesis and release of the primary CCR3 ligands CCL26 and CCL24 and will modulate other CCR3 ligands. The human A549 alveolar type II epithelium-like cell culture model was used for transfection and subsequent effects on CCR3 agonists. siRNAs were particularly effective. PCR showed a 60–80% decrease in mRNA and immunoblots showed up to 75–84% reduction of CCR3 in siRNA treated cells. CCR3-siRNA treatments reduced IL-4 stimulated CCL26 release and constitutive CCL24 release by 65% and 80%, respectively. Release of four additional CCR3 agonists RANTES, MCP-2, MCP-3 and MCP-4 was also significantly reduced by CCR3-siRNA treatments of the alveolar type II cells. Activation of eosinophils, assessed as superoxide anion generation, was reduced when eosinophils were treated with supernatants of A549 cells pretreated with CCR3-targeted siRNAs or AS-ODNs. Collectively, the data suggest that post-transcriptional regulation of CCR3 receptors may be a potential therapeutic approach for interrupting proinflammatory signaling.
The ROSA project–a new approach to sustainable sanitation in Eastern African cities
(2008-09) Langergraber, Guenter; Meinzinger, Franziska; Lechner, Markus; Mutua, Benedict M.
The ROSA project promotes resources-oriented sanitation concepts as a route to sustainable and ecologically sound sanitation. These concepts shall be applied in four cities in Eastern Africa, namely Arba Minch (Ethiopia), Nakuru (Kenya), Arusha (Tanzania) and Kitgum (Uganda). The project consortium comprises two partners from each of these countries, a university and the municipality as an end-user. For the pilot cities Strategic Sanitation and Waste Plans (SSWPs) will be developed for the whole city area. These SSWPs will come up with the best solution for the city combining several techniques according to the local requirements. Research topics addressed within ROSA are targeting the gaps for the implementation of resource-oriented sanitation solutions in peri-urban areas. They include an implementation study of the updated WHOguidelines for use of wastewater and excreta, the improvement and adaptation of resource-oriented sanitation technologies and the development of community based operation and management strategies. For the implementation of the complete SSWPs the ROSA consortium will develop strategies for further financing. The paper describes the general outline of the ROSA project and the situation in the four pilot cities based on the outcomes of completed baseline studies.
Classification of catchment risk areas using spatially distributed event-based soil erosion: a case of upper Njoro river catchment, Kenya
(WIT Press, 2008-12-19) Wambua, R.M.; Mutua, Benedict M.; Nyaanga, D.M.; Kundu, P.M.
Human-induced soil erosion and drastic change in land use practices have adversely infl uenced the land degradation and surface runoff response in upper Njoro River catchment. The drainage area is approximately 127 km2. Due to human activities, the land has been exposed to accelerated erosion and low land productivity, water scarcity, decline in ground water recharge, siltation of Lake Nakuru and other sediment sinks. This study was conducted to establish event-based risk areas for prioritized conservation within the catchment. Spatially distributed soil erosion map was created as a ratio of sediment yield to sediment delivery ratio (SDR). Modifi ed Universal Soil Loss Equation (MUSLE) integrated within a Geographical Information Systems environment was used to create the sediment yield map. Spatial data layers for the MUSLE were derived from a 20-m resolution Digital Elevation Model, soil property, land use maps and climatic data of the catchment. Land use map was derived from Landsat imagery via its processing using Integrated Land and Water Information Systems software. The results show that the spatially distributed soil erosion ranged from 0.06 to 0.51 t/ha for a 43.2-mm rainfall event. Spatially distributed SDR ranged from 0.09 to 0.82, while the average SDR for the whole catchment was 0.72. These values were derived using an empirical equation. A new contribution was made by developing spatially distributed slope length factor, SDR, runoff volumes, MUSLE parameters and classifi ed erosion risk areas for prioritized catchment conservation. This means that the event-based soil erosion classifi cation can be adopted for prioritized soil and water conservation within Njoro catchment.
CCL26-targeted siRNA treatment of alveolar type II cells decreases expression of CCR3-binding chemokines and reduces eosinophil migration: implications in asthma therapy
(2009) Errahali, Younes J.; Taka, Equar; Abonyo, B. O.; Heiman, Ann S.
The underlying infl ammation present in chronic airway diseases is orchestrated by increased expression of CC chemokines that selectively recruit leukocyte populations into the pulmonary system. Human CCL26 signals through CC chemokine receptor 3 (CCR3), is dramatically upregulated in challenged asthmatics, and stimulates recruitment of eosinophils (EOSs) and other leukocytes. CCL26 participates in regulation of its receptor CCR3 and modulates expression of a variety of chemokines in alveolar type II cells. Utilizing the A549 alveolar type II epithelial cell culture model, we carried out studies to test the hypothesis that CCL26-siRNA treatment of these cells would ameliorate Th2-driven release of the eotaxins and other CCR3 ligands that would, in turn, decrease recruitment and activation of EOSs. Results demonstrate that CCL26-siRNA treatments decreased interleukin4-induced CCL26 and CCL24 expression by > 70%. CCL26-directed small-interfering RNA (siRNA) treatments signifi cantly decreased release of CCL5 (RANTES), CCL15 (MIP-1δ), CCL8 (MCP-2), and CCL13 (MCP-4). In bioactivity assays it was shown that EOS migration and activation were reduced up to 80% and 90%, respectively, when exposed to supernatants of CCL26-siRNA-treated cells. These results provide evidence that CCL26 may be an appropriate target for development of new therapeutic agents designed to alleviate the underlying infl ammation associated with chronic diseases of the airways.
Characterization of greywater from urban and peri-urban areas of Nakuru municipality, Kenya
(Loughborough University, 2009) Raude, James M.; Mutua, Benedict M.; Chemelil, Mathew C.; Sleytr, Kirsten
Kenya faces serious challenges regarding water and sanitation services. Despite many years of government investment, existing facilities continue to deteriorate and have also failed to meet the demand of increasing population. These challenges are particularly severe in rapidly growing settlements of urban poor. One such settlement is Nakuru municipality which has an average annual population growth of about 8%. The municipality’s sewerage connection is inadequate (11% coverage) and only serves middle and high income areas. This study used a semi-structured questionnaire aiming at characterizing and determining the composition of greywater, besides identifying existing water supply and lifestyle characteristics. The total suspended solids range in greywater was 200-3500 mg/l and faecal coliform (FC) count 105 -106 100mL-1. High values of FC concentration in greywater can be associated with life style characteristics and the settlement patterns. These results were used to develop site specific greywater treatment systems ideal for peri-urban areas.
Norms, attitudes and gender perspectives in ecological sanitation
(Loughborough University, 2009) Mugure, Agnes; Mutua, Benedict M.
In Kenya, the urban poor are residing in the Peri urban areas of Nakuru Municipality with inadequate sanitation facilities. This study investigated attitudes towards urine diverting toilets to popularize their use as viable alternative sanitation. Face to face interviews among 231 household respondents using a semi structured questionnaire, field observations, focused group discussions and key informant interviews were performed. Most of the respondents reported that the ecosan toilets are a viable option due to congested housing pattern, desire to own a toilet (for those who never had a toilet before), geo hydrological conditions, improved privacy, and convenience among other factors. Most respondents preferred squatting type of urine diverting toilet, and are willing to reuse sanitized urine and feacal matter. Among the challenges noted include forgetfulness by some people to spray ash after defecating, misplaced water entering the toilet vault during cleaning and confusion in using the two holes. The provision for squat hole covers; modification of design, commitment and household change of behaviors are fundamental for encouraging more adoption and replication of the toilets.
The linkage between settlement profile and choice of sanitation system in peri-urban areas: a case study of Nakuru municipality
(WEDC, Loughborough University, 2009-05-22) Moseti, Y.K.; Kimani, Sammy N.; Mutua, Benedict M.
Presently human settlements in developing societies do not effectively address problems in urban areas including inadequate housing, unreliable energy sources, inadequate water supply, poor sanitation systems and lack of access roads in informal settlements. Recently, Nakuru town water supply has been characterized by chronic shortages and this threatens sanitation in residential and industrial functions within the Municipality. “Flying toilets” and pit latrines are conspicuous in low income high density settlements, while flush toilets, sewer systems and septic tanks are common among middle and high income low density settlements. A study was carried out to assess and map linkages between sanitation technologies and settlements profile in the municipality and examine implications of resource-oriented sanitation technologies. Results showed that sanitation situation in low income settlements and choice of sanitation technology is limited to multi-factors. 70% of respondents indicated a strain economically as a determining factor in the choice of sanitation technology. The research recommended the adoption of ecological sanitation as a paradigm shift from conventional sanitation.

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