Multidisciplinary Journal of Technical University of Mombasa

Editorial Note

Munga Cosmas Nzaka — 2025-12-30

Editorial Note

We would like to thank all our authors and co-authors who contributed to the successful release of this Issue 2 of Volume 4, 2025 of MJTUM. There are a total of 7 publications from different authors and co-authors, out of these 5 are research articles and 2 are review articles. These published articles cover a diverse array of fields ranging from Chemistry, Marine and Fisheries Sciences, Architecture and Built Environment, Biotechnology, to Mechanical and Automotive Engineering. The content of all the articles is as a result of dedicated research works from the authors and co-authors. MJTUM is hereby providing a platform to share the contents of these research and review works in contributing to knowledge dissemination to the scientific community and to all students in their quest to advance knowledge in their respective fields. MJTUM will continue to provide a platform for dissemination of high quality scholarly articles. It is my sincere hope that you will enjoy reading the wide scope of these published articles in this current issue as we prepare you for the release of Volume 5 of 2026.

Prof. Cosmas Nzaka Munga

Chief Editor, MJTUM

Treatment of selected Halogenated Organic Compounds in Water using Colloidal Silver Nanocatalysts under Reducing Borohydride Conditions

Tadicha Adan — 2025-12-30

Halogenated organic compounds (HOCs) are frequently encountered water contaminants. They are widely used as solvents or feed stocks in the production of paints, adhesives, lacquerers, pharmaceuticals and veterinary drugs, cosmetics, pesticides and herbicides. Most HOCs are recalcitrant, toxic and possible carcinogens. HOCs treatment in water may involve physical, biological and chemical processes. Chemical treatment via oxidation or reduction processes are preferred due to their ability to transform HOCs into environmental benign products. Compared to reduction, oxidation may produce toxic byproducts and thus for complete mineralization, huge amounts of redox equivalents are needed. Reductive dehalogenation is selective and more suited for HOCs treatment. It may employ electrocatalysts, metal catalysts and reagents. Nanoscale zero valent iron (nZVI) as an electron-releasing reagent is environmentally compatible but ineffective for transformation of saturated aliphatic HOCs containing < 2 Cl-atoms. Noble metals such as Pt, Rh and Pd are excellent hydrogenation catalysts for HOCs reduction but are expensive and susceptible to deactivation in water. Metallic Ag (Ag⁰) is a promising electrocatalyst for dechlorination of saturated aliphatic HOCs. Ag is relatively cheaper than the noble metals and is sparingly stable in water. Despite this potential, colloidal Ag⁰ catalysts have received less attention for HOCs treatment. In this study, optimal conditions were established for synthesis of colloidal Ag⁰ catalyst using sodium borohydride (NaBH₄). Calculated Ag⁰ activities for reduction of dibromomethane, monobromomethane, perchloroethylene, trichloroethylene and vinylbromide were 86.92 ± 2.61, 3.45 ± 0.17, 2.38 ± 0.07, 1.16 ± 0.05 and 3.21 ± 0.10, respectively. The reduction of diclofenac and bromocresol blue by Ag⁰+NaBH₄ was slow and incomplete due to catalyst deactivation. Thus, Ag⁰+NaBH₄ is more appropriate for reduction of aliphatic and olefinic C—Cl and C—Br bonds.

Different fishing vessel-gear combinations confirm resource-use overlap in small-scale fisheries of south coast Kenya

Bandari Samuel — 2025-12-30

Fish consumption globally has increased due to the rise in human population making fisheries resources vulnerable to overexploitation. The open access fisheries in Kenya coupled with the multi-fleet, multi-gear and multi-species nature of the fisheries make its management more difficult. A closer observation into the scenario proves the existence of resource use overlap among different vessel-gear combinations. This study assessed the resource use overlap among different vessel-gear combinations for the multi-gear and multi-fleet small-scale fishery in selected fishing areas in south coast Kenya. We conducted shore-based catch assessment from January 2019 to December 2021covering both the cool south east monsoon (SEM) season and the warm north east monsoon (NEM) season at Mkunguni fish landing site in Msambweni area and Shimoni fish landing site in Shimoni area. The data was analyzed for total fish landings and species composition by vessel-gear combinations, as well as analyzed for resource-use overlap. A total weight of 52.32 tons of fish was recorded over the study period, and this was higher in the NEM season (26.52 tons) than in SEM season (25.32 tons). An overall total of 321 species in 88 fish families were sampled. Mkunguni recorded more species (n = 253) than Shimoni (n = 186) and species richness was significantly higher in Mkunguni than Shimoni (p = < 0.0001). The most effective and preferred vessel-gear combinations overall were footfisher-speargun and dhows-handline. Seasonal species diversity also indicated an overlap in resource-use where different vessel-gear combinations landed multiple species with the highest number of species recorded by gears used in combination with canoe being handline (120 ± 8 species) and basket trap (87 ± 6 species). Fishing gears used with dhows being handlines which recorded the highest mean number of species caught (73 ± 4 species) and gillnet (58 ±5 species). The observation made in the presence of similar fish species in different vessel-gear combinations that had been used in different fishing grounds is a clear indication of resource-use overlap in the small-scale fishery.

A Review of the Role of Actinobacteria as a Source of Bioactive Compounds

Keroro Kelvin — 2025-12-30

A systematic review of 57 peer-reviewed studies published between 2015 and 2024 was conducted to provide information on the role of Actinobacteria as a source of bioactive compounds. Study emphases included ecological distribution, metabolite diversity, research approaches, and publication trends. The reviewed papers covered soil, marine, freshwater, plant-associated, and extreme environments. Soil-derived isolates accounted for 42% of reports, followed by marine (28%), extremophilic (15%), freshwater (10%), and plant-associated (5%) strains. Streptomyces and Micromonospora were the most frequently reported genera. In terms of production of bioactive compounds, 65% of studies confirmed production of antibacterial, antifungal, anticancer, antiviral, and anti-inflammatory metabolites. 20% presented preliminary but promising results and 15% reported no significant activity. 40% of studies employed genomic-based strategies such as genome mining and metagenomics, 35% applied chemical profiling techniques, and 25% used classical isolation and culture methods. Publication trends indicated steady global growth with a peak in 2021, while African contributions represented less than 5% of studies. The most commonly reported metabolites were antibiotics, antifungals, and biosurfactants, with aminoglycosides and macrolides being the most cited classes. The findings show that Actinobacteria is a potential resource for drug discovery therefore there is need for further bioprospecting.

Hydraulic Modeling and Flood Risk Assessment in the Hola and Bura Basins, Kenya: HEC-RAS-Based Simulation of the March 2024 El-Niño Event

Janga Joseph Tinga — 2025-12-30

This study presents a comprehensive hydraulic modeling and flood risk assessment of the Hola and Bura basins in Tana River County, Kenya, using the HEC-RAS 6.7 software. The model simulated the March 2024 El-Niño flood event, a climate-induced extreme rainfall episode, using a two-dimensional (2D) approach to capture complex flow dynamics across floodplains. Coupled with hydrologic inputs from HEC-HMS, the simulation produced detailed flood inundation maps and depth classifications, delineating shallow m), moderate (0.5–1.5 m), and deep m) flood zones across a total inundated area of 197.0 km²—representing 39% of the modeled basin. The analysis revealed critical floodplain features such as relict meanders and paleochannels that significantly influenced lateral water spread, emphasizing the importance of preserving natural floodplain connectivity. Validation using Sentinel-1 SAR imagery confirmed strong agreement between observed and simulated flood extents. The present study also assessed the vulnerability of key infrastructure assets, including roads, schools, hospitals, boreholes, and electric transformers. Findings indicate that critical services were either directly inundated or rendered inaccessible due to surrounding flood conditions, with power installations and boreholes particularly at risk due to exposure to deep, high-velocity flows. Based on the spatial hazard classification and exposure overlay, the study proposes targeted design improvements including elevated road embankments, flood-resilient water supply systems, and raised platforms for public utilities. The results demonstrate the value of integrating hydrodynamic modeling with satellite data and infrastructure mapping for informed disaster preparedness, climate adaptation, and land-use planning in flood-prone regions of East Africa.

Sustainable Concrete with Coir and Crushed Coconut Shells: Workability and Strength Performance

Kuta Joseph — 2025-12-30

The increasing demand for sustainable materials within the construction industry has heightened interest in alternative aggregates for concrete, motivated by escalating costs and environmental concerns associated with conventional natural aggregates. The overexploitation of these resources has led to scarcity and increased expenses, underscoring the necessity for cost-effective solutions that maintain concrete's performance and structural integrity. Furthermore, the improper disposal of agricultural by-products, such as coir and crushed coconut shells, exacerbates waste management challenges and poses environmental risks. This paper aimed to evaluate the workability and compressive strength of concrete incorporating coir fibers and crushed coconut shells as aggregate replacements. The study was conducted in the counties of Kilifi, Mombasa, and Kwale in Kenya, with a focus on the utilization of coir and crushed coconut shells in concrete mixtures. The experimental design involved the preparation of concrete mixtures with coir percentages of 0.1%, 0.2%, and 0.3%, along with crushed coconut shell aggregates at 10%, 20%, and 30% by volume. Key variables assessed included workability—measured through the Slump Test, Flow Table Test, and Vebe Consistometer. The mechanical properties, were evaluated via compressive strength and durability tests. A total of 72 concrete cubes and 72 short beams were prepared using locally sourced materials to ensure relevance to regional practices. Data collection adhered to standardized protocols, and the validity and reliability of measurement instruments were established through expert reviews and consistency checks. The study demonstrates that incorporating crushed coconut shell aggregates (CCSA) into concrete significantly reduces workability due to increased water demand and lower density. Conversely, adding coir fibers enhances workability, although excessive coir can negatively affect it. Compressive strength reduces making CCSA up to 20%, the minimum structurally usable mix, with, but further additions produces compression strength only suitable for non-structural use. The inclusion of 0.3% coir fibers further boosts compressive strength, especially with CCSA. This study recommends limiting coir to 0.3% for optimal workability and promoting CCSA use up to 20%, along with further research on their microstructural impacts.

Strategy Formulation and Organizational Performance in Dynamic Real Estate Markets: Evidence from Kenya

Katani Erastus Mwanjama — 2025-12-30

This paper empirically examines how strategy formulation influences organizational performance among real estate developers operating in Kenya’s turbulent and institutionally evolving markets. Grounded in the resource-based view, contingency, and dynamic-capabilities perspectives, the study tests a multidimensional framework incorporating environmental dynamics, strategic awareness and institutional support, and engagement. A census of 88 corporate members of the Kenya Property Developers Association (KPDA) was undertaken using a structured questionnaire analysed through multiple regression, moderated and mediated regression (PROCESS v 4.3), and multivariate analysis of covariance (MANCOVA). Results demonstrate that strategy formulation exerts a significant positive effect on organizational performance (β = 0.412, p < 0.001). Environmental dynamics significantly moderate this relationship (β = –0.203, p = 0.017), indicating that the strength of strategic influence diminishes under high turbulence. Strategic awareness and institutional support mediate the link between formulation and performance (indirect effect = 0.186, 95 % CI [0.072, 0.314]), while institutional engagement shows a direct positive effect (β = 0.337, p < 0.010). The overall model explains 68.9 % of variance in performance (R² = 0.689, F (5, 82) = 36.32, p < 0.001). MANCOVA tests confirm significant multivariate effects for role, organization type, and development focus (Wilks’ Λ = 0.558, F (1, 78) = 98.38, p < 0.001). Findings validate the complementarity of deliberate strategic planning, adaptive learning, and institutional connectivity. They extend strategic-management theory to emerging-market property sectors and provide a replicable, statistically robust blueprint for evaluating strategy–performance relationships under environmental turbulence.

Sustainable Hydrogen Production through Steam Methane Reforming and Water Electrolysis – A Review

Mwadhi William Mulewa — 2025-12-30

Nearly half of the hydrogen produced worldwide comes from the most popular and economical method of hydrogen synthesis, methane steam reforming (MSR). However, there are a number of challenges that must be conquered before MSR can be widely used, despite the fact that it is a well-established technique. The primary research gaps in the MSR process center around improving the catalyst longevity and efficiency, addressing the process's high energy consumption and carbon emissions, and enabling cost-effective small-scale hydrogen production. As an alternative, electrolysis of water could yield pure hydrogen. Nevertheless, hydrogen production from water electrolysis is synonymous with high costs (electricity, capital), as well as obstacles like the synthesis of more affordable and effective catalysts for the procedure, enhancing system intergration with renewables, and achieving true large scale manufacturing and scalability. In this review paper, both processes have been critically analyzed to give insights into current processes, the challenges faced, and prospects. Since both methane steam reforming and water electrolysis generate valuable hydrogen, optimization of the two could offer a more sustainable and reliable source of energy.