http://41.89.164.27:8080/xmlui/handle/123456789/255 2026-04-03T15:35:51Z http://41.89.164.27:8080/xmlui/handle/123456789/2535 ANTIOXIDANT AND ANTIDIABETIC PROPERTIES OF Mondia whitei ROOT EXTRACT IN STREPTOZOTOCIN-INDUCED DIABETIC WISTAR RATS GITAU, KENNEDY KAMAU The rising global prevalence of diabetes mellitus (DM) and its complications presents a major health challenge and is exacerbated by the lack of a definitive cure and the side effects of existing treatments, thus, highlighting the need for safer and more sustainable anti-diabetic agents. This study investigated Mondia whitei root extract as an alternative therapeutic option for DM. While traditional medicine suggests that M. whitei possesses antioxidant and anti-diabetic properties, scientific validation is limited. This research aimed to address this gap. Qualitative phytochemicals analysis of crude root extract of M. whitei was done and it’s in vitro antioxidant properties evaluated through 2,2- diphenyl-1-picrylhydrazyl (DPPH) scavenging activity and ferric reducing antioxidant power (FRAP) assays. DM was induced in twenty-four male Wistar rats by a single intraperitoneal injection of 65 mg/Kg body weight (bwt) of streptozotocin (STZ). Animals were randomly assigned to five groups each containing six subjects; Group I (normal control, saline), Group II (diabetic control, saline), Group III (diabetic rats 200 mg/Kg bwt extract treatment), Group IV (diabetic rats 400 mg/Kg bwt extract treatment), and Group V (diabetic rats 100 mg/Kg bwt metformin treatment). Treatments were orally administered for 21 days. Fasting body weights and blood sugar levels were measured weekly. After 21 days, animals were sacrificed and their blood and liver tissue samples collected followed by serum lipid profile, liver and kidney function indices analysis. Liver malondialdehyde (MDA) levels were measured, and liver and plasma’s ferric-reducing capacity were evaluated. Statistical analysis was performed using R software, with paired Student’s t-test and ANOVA determining statistical significance at 95% confidence level. The qualitative phytochemical analysis of the crude M. whitei root extract revealed the presence of saponins, phenols, tannins, alkaloids, flavonoids, glycosides, coumarins, steroids, and terpenoids, while anthraquinones were not detected. The extract significantly scavenged DPPH radical and reduced ferric ions in vitro. M. whitei also showed significant hypoglycemic, hypolipidemic and significantly reduced serum gamma-glutamyl transferase (GGT), alanine aminotransferase (ALT) and alkaline phosphatase (ALP). M. whitei treatment also significantly increased liver and blood plasma capacity to reduce ferric ions as well as protected liver tissues from lipid peroxidation as indicated by significantly reduced levels of MDA. However, M. whitei showed no significant serum urea and creatinine levels decrease. In conclusion, the phytochemical-rich M. whitei root extract demonstrated anti-diabetic, antioxidant, hypolipidemic and hepatoprotective effects in STZ-induced diabetic rats, highlighting its potential as a natural candidate for the management of DM and its complications. 2025-01-01T00:00:00Z http://41.89.164.27:8080/xmlui/handle/123456789/2406 ENVIRONMENTAL OCCURRENCE AND ECOTOXICOLOGICAL RISKS OF CONTAMINANTS OF EMERGING CONCERN IN THE RIVER ATHI BASIN, KENYA: ANALYTICAL AND KINETIC ADSORPTION STUDIES USING AGRICULTURAL WASTE BIOCHARS CHEBII, FAITH JELAGAT Globally, the environmental occurrence of Contaminants of Emerging Concern (CECs) including Active Pharmaceutical Ingredients (APIs), Personal Care Products (PCPs) and pesticides has raised ecological and human health concerns. However, as the developed world make efforts to establish regulatory measures to mitigate their effects, developing nations including Kenya are lagging, partly due to unavailability of adequate data. Remediation of CECs in water can be achieved via photodegradation, advanced oxidation process, bioremediation, chemical degradation and activated carbon utilization. Adsorption, a cheaper and convenient alternative using the available agricultural wastes products, as biosorbent materials have not been fully explored. The objectives of this study were to determine multi-class CECs load and concentrations, determine ecotoxicological risks towards algae, Daphnia magna and fish, and potential point-of-use technologies via adsorption using Rice Husk Biochar (RHB), Avocado Seed Biochar (ASB)and Banana Peel Biochar (BPB). Water samples were collected from 24 sites across the River Athi basin area, Kenya. Extraction of water samples was done using Solid-Phase Extraction (SPE) and the CECs were analyzed using Ultra-High-Performance Liquid Chromatography coupled to High Resolution Orbitrap Mass Spectrometry (UHPLC-HRMS). The equilibrium adsorption isotherm studies were conducted for 86 CECs using ASB, BPB and RHB and the data was correlated using the non-linear curves of Langmuir and Freundlich rate equations. RHB was used in the adsorption kinetic studies for 86 CECs and the kinetic data acquired were correlated with the non-linear curves of Pseudo-First Order (PFO), Pseudo Second Order (PSO), Elovich and the Weber-Morris intraparticle diffusion models. The fitting performance of each model onto the kinetic data was guaranteed using adjusted R2 and the chi square values. The results of this analysis indicated that 57 CECs comprising 31APIs (0.4 ng L-1 – 142 µg L-1), 6 PCPs (0.7 – 570 ng L-1) and 20 pesticides (0.3 ng L-1 – 8.3 µg L-1) were detected. The maximum loads varied from 217 g day-1 (APIs) to 46 g day-1 (PCPs). Individually, Carbamazepine, Nevirapine, Sulfamethoxazole and DEET were the most ubiquitous CECs, with detection frequencies (DF) higher than 80%. The highest concentrations were observed at river sites that are heavily impacted by informal settlements, highlighting the critical role of slums in pollution of urban rivers. At least 8 CECs including Acetamiprid, Alachlor, Atrazine, Diuron, Nevirapine and Paracetamol showed potential risk to algae, Daphnia magna and fish, as exemplified by Risk Quotients (RQ) up to 174. Similarly, potential risk of antibiotic resistant bacteria development is evident due to exposure to Metronidazole, Sulfamethoxazole and Trimethoprim (RQ up to 64). Comparison of removal efficiencies of the CECs using the ASB, BPB and RHB showed that ASB and RHB had impressive % Removal efficiencies (94.0% - 98% and 87% - 99%) respectively compared to BPB (87% -93%). The lower %RE (% Removal Efficiencies) at lower concentrations for all the selected biochars is attributed to formation of bulky water clusters which may not be accommodated in the micropores on the surfaces of the biochars. The adsorption mechanism may be attributed to π-π electron donor- acceptor interaction, pore filling, ionic interactions and hydrogen bonding between the CECs molecules and the surfaces of the biochars. The kinetic adsorption analysis revealed that the kinetic data acquired for virtually 80% of the compounds were best described by the Elovich kinetic model, indicating that chemisorption was more pronounced on a heterogenous adsorbent surface as to physisorption and the intra – particle diffusion mechanisms. The R2 values approached unity and low Chi-square values approached zero. The equilibrium isotherm data fitted well both with Langmuir and Freundlich models with R2 approaching unity in most instances. However, Freundlich model had higher rate constants as to Langmuir models, an indicator that adsorption process was best described with a multilayer structure than the monolayer. There is a need to sensitize communities in informal settlements on proper waste disposal methods and the government agencies should include CECs in their monitoring schedule. ASB and RHB should be considered in the development of point-of-u 2024-01-01T00:00:00Z http://41.89.164.27:8080/xmlui/handle/123456789/2285 HEAVY METALS IN WATER, SOIL AND PUMPKIN (Cucurbita maxima) LEAVES FROM SHIYALU-LURAMBI AREA KAKAMEGA COUNTY KENYA: CONTAMINATION LEVELS AND SPECIATION ANALYSIS NEKESA, DOREEN MESO Pollution of the environment by heavy metals is a major global concern. Arsenic (As), cadmium (Cd), lead (Pb), nickel (Ni), copper (Cu), and zinc (Zn) present the greatest environmental threat because of their widest distribution and known toxic effects in humans, plants, animals and lower biota. The study was designed to assess the level of selected heavy metals in potable water, soils and Pumpkin leaves (Cucurbita maxima) samples to determine their availability and potential accumulation along the food chain. Samples for the field investigation were collected from randomly selected sites, transported to the research laboratory where they were treated and analyzed for Cd, Pb, Ni, Cu, and Zn using Atomic Absorption Spectroscopy (AAS). Arsenic was determined calorimetrically using Arsenic Test Kit (ATK). Inductive coupled plasma atomic emission spectroscopy (ICP-AES) was used to perform speciation studies for Cd and Pb in soil samples. It was found that whereas the As, Ni, Cu, and Zn concentrations in water, soil and plants were well within the respective World Health Organization (WHO) limits, both the Pb and Cd levels water (Pb -0.0925-0.5680 Cd -0.3911-0.5541); soil (Pb -1.2252-1.9279; Cd -0.6153- 0.7674-) and plants (Pb -1.0482-1.3892); Cd 0.1070-0.11833) respectively exceeded the permissible WHO standards for studied media, respectively. The Soil Pb and Cd were present in the bioavailable exchangeable fractions (0.42 mg/kg, 0.21 mg/kg) and reducible fraction (0.99 mg/kg, 0.28 mg/kg), respectively. Lead (Pb) and Cd in the soils posed significant risk of overexposure because of their high levels and speciation resulting in bioaccumulation and magnification in the plant tissues investigated. Because the overall toxic consequences of excessive exposure to these metals, it is recommended that the levels of heavy metals in plants, water, and soil in the affected areas need to be routinely assessed and measures taken to avert potential environmental and public health damage. 2024-01-01T00:00:00Z http://41.89.164.27:8080/xmlui/handle/123456789/2236 BACTERIOLOGICAL QUALITY OF FRESH MEAT SOLD WITHIN ELDORET TOWN KOECH, EDWIN CHERUIYOT Meat is the primary source of proteins in many parts of Africa. In many cases however, it is major point of entry of many zoonotic diseases. Further, due to the long and many procedures involved in the meat industry, it is also implicated with many diseases associated with poor hygiene. The present study was carried out to assess the general microbiological quality of meat (beef, chevon and mutton) sold in Eldoret Town of Uasin Gishu County. The objectives of the study were; to investigate the physiological conditions of the meat, assessing the bacterial load of the meat, and biochemical characterization of selected bacterial pathogens found on the meat. Five major abattoirs were sampled for this study; Kaburwo in Langas, Maili Nne in Huruma, Cyrus in Munyaka, Eldoret main, and Teresia in Moiben representing all the major peri-urban centres of the Town. Five butcheries in the town were also selected for the study. The pH and temperatures of the carcasses were the physiological parameters measured and were recorded at the sampling sites. Meat samples were aseptically collected and taken in sterile bags and kept at 4˚C. One gram of each meat sample was mixed with 0.4 ml of 0.1% of buffered peptone water for 2 minutes. Serial dilutions were carried out and followed by plating via pour plate technique. The plates were incubated for 24 hrs at 37 ˚C after which total plate count was done to determine the bacterial load of the meat samples. Biochemical typing was done on pure isolates to determine the presence of Escherichia coli, Staphylococcus aureus, and Proteus vulgaris. PH values ranged from 5.5 to 6.77 with the pH of the meat obtained from butchery consistently registering low values compared to the ones from the abattoirs. Temperatures of the carcasses ranged from 23 ˚C to 26.95 ˚C. The lowest temperatures were obtained from the carcasses from Teresia abattoir. Statistical analysis of variance was used to determine level of signifance between the microbial load and factors; temperature and PH on meat sample collected. Correlation regression analysis was used to determine the influence of the physiological factors measured on the numbers of colony forming units(cfus). Statistical analysis was done using Ms Excel 2013. The meat in all the samples sites were found to be of poor bacteriological quality as the bacterial load was found to be higher than the recommended levels. The highest bacterial load was found in the carcasses in the butchery with an average of 19.8 cfus g/ml while the lowest was from the Maili Nne abattoir with an average of 4.9 cfus g/ml. Among the abattoirs, Teresia had the highest bacterial load of 9.2 cfus. Temperature was found to be positively correlated with cfu albeit weak (0.177) while pH was negatively correlated with the same (-0.478). Staphyloccocus aureus was the major pathogenic bacteria isolated from all the carcasses being at 26% of the isolated bacteria. Proteus vulgaris was at 11% and Escherichia coli at 8%. These differed from one sampling site to another but the order of abundance remained uniform. More public health education on the appropriate hygienic practices ought to be rolled out to help achieve a better microbiological quality status of the meat sold in Eldoret Municipality. 2024-01-01T00:00:00Z http://41.89.164.27:8080/xmlui/handle/123456789/2069 COMPUTER-BASED LABORATORY SIMULATIONS AND DEVELOPMENT OF INQUIRY SKILLS IN ELECTRO-CHEMISTRY IN SECONDARY SCHOOLS INSTRUCTION IN BOMET COUNTY CHEPKORIR, SALOME Computer technology has advanced to the point where it can significantly enable inquiry learning to be used at various levels, and offer new tools for representing the nature of science in the classroom. Traditional education approaches which are teacher- centered are inadequate in developing scientific skills. The aim of this research was to examine the use of Computer-Based Laboratory Simulations (CBLs) in development of inquiry skills in electro- chemistry in secondary school chemistry instruction, Bomet County. Philosophical paradigm adopted in the study was positivism. It originated in the natural sciences and focuses much on scientific method of testing hypotheses which paves way for further investigations. The study was guided by constructivist theory of learning as advocated by Jean Piaget where learner participates actively in learning process to make meaning out of it. The study used Quasi-Experimental Research Design. Solomon-Four Non-equivalent Groups Design was applied. Four secondary schools in Bomet County were purposively sampled on the basis of availability of computers. Three hundred and sixty-nine subjects took part in the investigation. The four schools were allocated to control and treatment groups by simple random sampling method. All groups of students were taught similar chemistry content (electro-chemistry). However, experimental groups used CBLs approach while the control groups used regular teaching methods (RTM) including teacher demonstrations and lecture. The control group II and experimental group I were pre-tested prior to the implementation of the CBLs treatment. After four weeks, all the groups (four) were post-tested using the Students’ Chemistry Achievement Test (SCAT) which was authenticated by education experts and pilot tested before using to validate its reliability. Data was analysed using ANCOVA and one-way ANOVA at a significant level of coefficient alpha (α) equal to 0.05. The findings indicated that computer-based laboratory simulations assisted students in acquisition of scientific inquiry skills (P<0.05). These skills were hypothesis formulation, experimental design, data collection and analysis, critical thinking and problem-solving, collaboration, and communication. Computer based laboratory simulation had significant effect on chemistry achievement (P<.0.05). CBL was more effective and efficient method as opposed to traditional method. CBLs strategy as well as RTM had no significant difference based on gender (P>0.05). CBLs also had significant influence on attitude of students which enhanced performance in chemistry (P<0.05). The study concluded that CBLs had significant influence on achievement in chemistry since it assisted the learner to develop inquiry skills than RTM. The study recommended teacher training colleges and universities to include CBLs as part of their training programmes to empower teachers on the use of new digital approaches. The findings of this investigation will be beneficial to the curriculum developers, Kenya Institute of Curriculum Development (KICD) as well as chemistry instructors on the use of CBLs in teaching chemistry at secondary school level. There is need for a comparative study on learners’ motivation and self-concept in chemistry instruction through CBLs approach verses those taught through traditional methods. 2023-08-01T00:00:00Z http://41.89.164.27:8080/xmlui/handle/123456789/2059 INVESTIGATION OF Pavonia urens AS A POTENTIAL BIOSORBENT IN HEAVY METAL REMOVALTHROUGH COMPLEXATION RUTTO, SALINA Metal ion-related environmental pollution poses a possible risk to human life. This is a result of various chemical wastes being released into the environment after being treated in an affordable and effective manner. Several herbs have been reported for use in heavy metals removal in wastewater. This study aimed at investigating the phytochemicals present and demonstrating the possible use of Pavonia urens leaves as adsorbent material through formation of a complex with selected metals zinc (Zn), copper (Cu) and nickel (Ni) from aquatic environment. The plant was collected from Uasin Gishu County and air dried before crushing. The ground powder was soaked in organic solvents (hexane, ethyl acetate, and acetone) of increasing polarity each for 48 hours followed by filtration and drying. The Four fractions obtained were labelled 1A, 2A, 3A and 4A. The GC-Mass spectrometer (MS) identified compounds with functional groups hydroxyl (OH), amine (-NH), and (-COOH). The ability of Pavoniaurens to complex with bimetallic ions in aqueous solution was also investigated using UV-VIS spectrometry. The interaction of these ions with functional groups revealed by UV-VIS analysis showed higher complexation for copper ions and zinc was the least. Plant material containing known concentration of the given metal ions was prepared for analysis at a fixed pH of 6, temperature of 298 K and 300 K, dosage of plant material 1 g and agitation speed at 125 rpm. One gram (1 g) of plant material was introduced to every 100 mL solution. Change in concentration was noted at intervals of 20 minutes using Atomic Absorption Spectrometer (AAS) until the rate of biosorption was constant. With regard to contact time and temperature, the biosorption of Cu (II), Ni (II), and Zn (II) ions on Pavonia urens leaves in a batch system was examined. The first step of the biosorption, which was rapid, happened in two stages, with Zn being the least biosorbed while Cu was the most. Compared to the Freundlich and Temkin isotherms, the Langmuir isotherm more closely matched the experimental results. The adsorption reactions were demonstrated to be spontaneous because ΔG 0< 0, feasible and exothermic (ΔHo < 0). P. urens contains bioactive species and is a viable alternative as an economical, environmentally friendly bio-sorbent that may successfully complex with metal pollutants in aqueous solution. As a result, P. urens merits exploration in the search for key chemicals in drug discovery as well as for use as an adsorbent. 2023-09-01T00:00:00Z http://41.89.164.27:8080/xmlui/handle/123456789/2052 BIOGENIC SYNTHESIS AND CHARACTERIZATION OF ZnO AND CuO NANOPARTICLES FROM Entada abyssinica AND Warburgia ugandensis LEAF EXTRACTS FOR ANTI-BACTERIAL APPLICATIONS LEMEITARON, PETER NJENGA In this study, biosynthesis, structural characterizations, optical and bactericidal properties of copper oxide and zinc oxide nanoparticles have been documented. Copper oxide (CuO) and zinc oxide (ZnO) nanoparticles were prepared using Entada abyssinica (EA) and Warburgia ugandensis (WU) leaf extracts. EA and WU possessed various biomolecules identified in GC-MS and FT-IR analysis which acted as reducing, capping and stabilizing agents in the synthesis of ZnO and CuO nanoparticles. The two-plant species had total phenolic contents, total flavonoid contents and total tannins contents obtained by optical means in the range of 19-58 mg/g, 940-1400 mg/g and 0.6-4.9 mg/g of the acid equivalents, respectively. The total percentage contents of saponins and alkaloids were in the range of 0.94-1.33 % and 1.27-1.42 % respectively. The green route synthesized CuO and ZnO nanoparticles were characterized using UV-VIS (Ultra-Violet Visible Spectroscopy), FTIR (Fourier Transform Infra-red) spectroscopy and X-ray Diffraction (XRD) instrumental methods. The visual observation of color changes during synthesis, the maximum SPR (Surface Plasmon Resonance) peaks observed in the UV-VIS spectra at varied synthesis parameters and the well-developed FT-IR peaks of functional groups responsible for the formation of the nanoparticles confirmed fabrication of nanoscale materials. Time and pH variations were the experimental control parameters. The XRD calculation of average particles sizes confirmed that the synthesized CuO and ZnO NPs were within the nanoscale range. The evaluation of the anti-microbial activities of the biosynthesized nanoparticles against Escherichia coli and Staphylococcus aureus bacteria was significant since p-value was less than 0.05. In comparison with other test samples against the two bacterial strains selected, the copper oxide nanoparticles synthesized from EA leaf extracts had higher zones of inhibition of 12.0±1.0 mm against Staphylococcus aureus pathogen. The lowest inhibition was shown by CuO NPs synthesized using Warburgia ugandensis leaf extracts against Escherichia coli (7.3±0.6 mm). The research can therefore contribute to the use and documentations of several locally available plants in Kenya in the synthesis of beneficial CuO and ZnO nanoparticles in the treatment of various illnesses. 2023-09-01T00:00:00Z http://41.89.164.27:8080/xmlui/handle/123456789/2033 ANTIDIABETIC PROPERTIES OF Tarchonanthus camphoratus IN FRUCTOSE-INDUCED DIABETIC WISTAR RATS NGENO, BENARD KIPROTICH Tarchonantus camphoratus (TC) has been used traditionally to manage several diseases such as diabetes mellitus (DM) including in Kenya but its anti-diabetic efficacy has not been scientifically evaluated. Therefore, this study aimed at evaluating the antidiabetic properties of Tarchonantus camphoratus crude leaf extract in fructose-induced diabetic Wistar rats. DM in rats was induced using high fructose (25% w/v) in drinking water in experimental groups for 12 weeks. Rats were divided after the DM induction into five groups (n=7 per group) as follows: Group I, normal control; Group II, diabetic untreated; Group III diabetic treated with metformin (100 mg/kg.bw/day), Groups IV and V; diabetic treated with 300 (low dose –LD) and 600 (high dose – HD) mg/kg.bw/day of TC extract respectively. Oral treatments were administered daily for 21 days. Changes in fasting body weights and blood glucose levels were monitored weekly. At the end of the treatment period, oral glucose tolerance test, skeletal muscle tissue weights and serum lipid profile parameters were analysed. For renal function, serum creatinine and urea were analysed while for liver function, serum alkaline phosphatase (ALP), aspartate aminotransferase (AST) and alanine aminotransferase (ALT), total proteins (TP), C-reactive protein (CRP) and albumin (ALB) were analysed. The skeletal muscle triglyceride (TG) mass was also analysed. Phytochemicals in the TC crude leaf extract were qualitatively analysed using standard procedures. Statistical analysis was done by Tukey’s test and one-way analysis of variance (ANOVA). Values with p < 0.05 were considered to be statistically significant. After 12 weeks, DM was successfully induced in the diabetic untreated group with rats having significantly higher body weights compared to all other groups (p ˂ 0.05). As compared to the untreated controls, there was a significant amelioration in fasting hyperglycemia in HD and LD groups (33.9% and 27.30% respectively). There was also increased glucose tolerance observed in both treatment groups. Further, TC extract significantly improved fructose-induced hypertriglyceridemia in the treatment groups compared with DM groups. The serum levels of ALP, ALT, and CRP were significantly reduced while TP and ALB were elevated in the extract-treated diabetic rats compared with unaltered DM rats. DM group also exhibited significantly higher skeletal muscle TG mass when compared to normal control and diabetic treatment groups. The observed hypoglycaemic and hypolipidemic activities in the diabetic treatment groups could be associated with the phytochemicals present in TC extract. TC crude leaf extract therefore possesses potential for alternative medicine for DM treatment and management. 2023-10-01T00:00:00Z http://41.89.164.27:8080/xmlui/handle/123456789/1765 QUANTIFICATION OF Cr +3, Cr +6, TOTAL CHROMIUM, AND PHYSICOCHEMICAL CHARACTERISTICS OF TANNERY WASTEWATER EFFLUENTS: A case study of Bata Tanneries, Kenya MARITIM, GEOFFREY KIPLANGAT Kenya's tanning industry is a key economic sector. Leather processing generates toxic effluents depending on the process. Bata leather industries in Kenya have been discharging effluent to nearby rivers leading to human and environmental pollution. The current study sought to carry out quantification of chromium and physicochemical characteristics of tannery wastewater effluents: “A case study of Bata Tanneries, Kenya”. Using grab sampler, water samples were obtained from four sites (S1 – Pre-tanning, S2 – Tanning, S3 – Post-tanning, and S4 – Drainage to the river). The samples were transported to the Tea Research Foundation of Kenya in a cold box for chemical analysis. Bis(salicylaldehyde) orthophenylenediamine reagent was used to complex Cr 6+ in non-ionic micellar media to dertermine the concentration of Cr +6. Double beam uv/vis spectrophotometer (perkinelmer) was used in the analysis. Physiochemical parameters were determined from the collected samples and results were with compared with NEMA, KEBS and WHO set standards. Total Cr level was analysed using inductively coupled plasma atomic emission spectrometry (ICP-AES). The mean range levels obtained from (S1, S2, S3 and S4) Bata leather tanneries in Kenya were as follows; total dissolved solids (TDS) 137.70 and 270.00 mg/L, DO 8.40 and 10.60 mg/L, pH concentrations ranged between 1.52 and 8.20. EC 1348.8 and 1385.00 mS/cm at S3, temperature 22.70 and 27.90OC, biological oxygen demand (BOD) 3141.20 and 5477.70 mg/L, total suspended solids (TSS) 148.00 mg/L to 284.00 mg/L, total solids (TS) 286.00 and 554.00 mg/L. Chemical oxygen demand (COD) 5986.70 to 9093.20 mg/L, colour (Pt-Co) 488.50 and 787.20 Pt-Co. The mean levels of total chromium, Cr 3+and Cr 6+ in effluent samples were 573.71 and 72.370, 12.08 and 1.37, and 560.38 and 70.69 mg/L, respectively. It is evident from the results of this study that high percentage of 98.05 ± 0.15 % from the initial concentration, added and found concentration of 2.00 ± 0.00, 2 ± 0.00 and 2.25 ± 031, respectively. All values of physicochemical parameters exceeded WHO standards except for temperature which was within the range. In comparison with the two methods, UV spectroscopic did best in comparison with ICP- AES in a non-ionic micellar media though with no significant difference (t = 0.2222, p= 0.8350. The ministry of Environment should therefore enforce the law concerning water pollution and prosecute those who are found culpable. Polluter pay principle should be applied to the company. 2022-10-01T00:00:00Z http://41.89.164.27:8080/xmlui/handle/123456789/1752 WATER QUALITY OF ATHI RIVER AND ITS TRIBUTARIES BASED ON SELECTED PHYSICAL-CHEMICAL PARAMETERS, HEAVY METALS AND BACTERIAL LEVELS MASIME, SEWE PHILIP Pollution is one of the major challenges facing water resources management in Kenya. This study was carried out to assess and monitor water quality status of the Athi River and its tributaries based on selected basic physical-chemical parameters (electrical conductivity, pH, temperature, TDS, TSS, ammonia, sulphide, nitrate, orthophosphate, BOD and COD), heavy metals (Fe, Cu, Cd, Cr, Pb, Mn and Zn) and bacteria (total coliforms, E. coli, salmonella and shigella). This is because of the perceived high pollution in Athi River and its tributaries. One hundred and ninety-two (192) water samples were randomly collected employing grab technique. The parameters were analyzed using standard methods for the examination of water and wastewater. For example, heavy metal analysis was done by digestion of 100 mL of water sample by addition of 5 ml of concentrated nitric acid in a fume chamber. Then the digested samples were analyzed using atomic absorption spectrophotometer (AAS SHIMADZU 7000, Japan). The pH (6.4 to 9.78) was generally within the standards for natural portable water while the temperature varied between 17.1 oC and 31.8 oC. The electrical conductivity (EC) ranged from 32 µS/cm to 2005 µS/cm while total dissolved solids (TDS) recorded concentration ranging from 20 mg/L to 1243 mg/L. Total suspended solids (TSS, 4 - 840 mg/L), chemical oxygen demand (COD, 14 - 3360 mg/L and biochemical oxygen demand (BOD, 1 - 640 mg/L)) recorded wide concentration range. Other parameters measured include sulphide (<1 - 192 mg/L), nitrate (ND - 44 mg/L), orthophosphate (0.1 -18 mg/L) and ammonia (ND - 204 mg/L). Levels of analyzed heavy metals were detected in the overall range of ND – 7.6 mg/L with cadmium, copper and chromium not detected. Iron levels ranged from 0.01 – 7.6 mg/L, lead ND – 0.7 mg/L, zinc ND – 3.4 mg/L and manganese ND – 4.3 mg/L. High bacterial counts recorded in collected water samples were: Salmonella (1 – 1.01×102 ) counts, Escherichia coli (4 - 1.79×107 cfu/100 mL), Shigella (1 – 1.11×102 counts) and total coliforms (20 – 6.03×107 cfu/100 mL). Some of the physical-chemical parameters (such as, BOD and COD) values in effluent samples discharged into the rivers by the wastewater treatment plants were higher than the KEBS and WHO tolerable levels. Consequently, more effort should be put by the relevant government agencies and departments to address pollution challenges in the Athi River basin 2022-01-01T00:00:00Z