Physico-Chemical Parameters, Selected Heavy Metals and Nutrients in Water, Fish and Sediments from Lake Turkana, Turkana County, Kenya
| dc.contributor.author | Munene, Paul Murimi | |
| dc.date.accessioned | 2024-09-26T08:07:56Z | |
| dc.date.available | 2024-09-26T08:07:56Z | |
| dc.date.issued | 2024-06 | |
| dc.description | A Thesis Submitted in Partial Fulfillment of the Requirements for the Award of the Degree of Master of Science in Applied Analytical Chemistry in the School of Pure and Applied Sciences of Kenyatta University, June 2024 | |
| dc.description.abstract | The degradation of aquatic ecosystems by ever-increasing pollutants from anthropogenic activities aggravates health problems, safe water and food scarcity globally. Lake Turkana is an important resource for water, food and recreation in Turkana County, Kenya. However, wastes from urban areas, residential areas, transportation and agriculture could alter physico-chemical parameters, heavy metal and nutrient levels in its water, fish and sediments. This study determined physico chemical parameters, selected heavy metals and nutrients in water, fish and sediments from Lake Turkana, Turkana County, Kenya. Water physico-chemical quality parameters: temperature, pH, electrical conductivity (EC), dissolved oxygen (DO), salinity, total dissolved solids (TDS) and oxidation-reduction potential (ORP) levels using YSI Pro 1030 Multiparameter electrode were determined. The study also analyzed lead, cadmium and chromium in water, Oreochromis niloticus and sediments using Flame Atomic Absorption Spectroscopy (iCE3300 AA System). Similarly, the study investigated nitrates and phosphates in water using visible spectrophotometer (Vis 130 Spectrophotometer). Water and sediments from Napasinyang’ River Mouth, Impressa Beach, Long’ech Beach, Lobu Beach and Turkwel/Kerio River Mouth were sampled and analyzed for lead, cadmium and chromium. Additionally, flesh and liver samples from Oreochromis niloticus in the lake were analyzed. The mean analyte levels were compared across the sampling sites using ANOVA and also with WHO and USEPA standards as appropriate. Heavy metal levels were also compared between fish and water and between water and sediments using student’s T-test. The results indicated physico-chemical parameters of the lake water as follows: temperature (28.24±0.96 to 28.86±0.38°C), pH (9.04±0.21 to 9.46±0.06), electrical conductivity (281.57±0.41 to 289.46±3.95 Ωcm-1 ), dissolved oxygen (6.3±0.79 to 7.04±0.05 mg/L), salinity (1.67±0.00 to 1.70±0.01 ppt), TDS (2093.4±0.39 to 2135.8±4.86 mg/L) and ORP (-54.22±0.12 to 588.14±0.51 mV). The results also showed lead (0.11±0.01 to 0.12±0.00 mg/L), cadmium (0.00±0.00 to 0.03±0.00 mg/L) and chromium (0.01±0.00 to 0.03±0.01 mg/L). The water nutrient levels were: nitrates (5.52±0.31 to 10.04±1.82 mg/L) and phosphates (0.47±0.06 to 0.72±0.15 mg/L). The levels of studied heavy metals in Oreochromis niloticus’s flesh and liver were: lead (0.57±0.08 and 3.34±1.26 mg/Kg), cadmium (0.02±0.00 and 0.32±0.15 mg/Kg) and chromium (0.12±0.01 and 0.51±0.18 mg/Kg). The results of sediment heavy metal analysis were: lead (0.56±0.11 to 1.01±0.03 mg/Kg), cadmium (0.02±0.00 to 0.24±0.10 mg/Kg) and chromium (0.11±0.03 to 0.2±0.05 mg/Kg). The pH and TDS in Lake Turkana’s water exceeded the WHO standards of 6.5-8.5 and 600.0 mg/L respectively. The water lead levels exceeded WHO standard of 0.01 mg/L. Water cadmium levels surpassed WHO standard of 0.003 mg/L in Impressa Beach and Long’ech Beach. The Lake Turkana’s water nitrate levels complied with WHO standard of 50.0 mg/L. The phosphate levels were beyond USEPA standard of 0.024 mg/L. The levels of lead in the Oreochromis niloticus’s flesh and liver exceeded WHO limits of 0.5 mg/Kg and were considerably loftier (p < 0.05) than in the water column. Furthermore, the levels of lead, cadmium and chromium in Lake Turkana’s sediments complied with USEPA standards of <40.0, <6.0 and <25.0 mg/Kg respectively. However, the lead, cadmium and chromium levels in sediments were appreciably higher (p < 0.05) than in the overlying water. The study did not consider seasons, time, tides, other fish organs and species. The study recommends that water for human use be treated for pH, TDS, lead, cadmium and phosphates. Detoxification of heavy metals in Oreochromis niloticus to be done. The sediments to be protected from accumulating lead, cadmium and chromium beyond USEPA standards. | |
| dc.description.sponsorship | Kenyatta University | |
| dc.identifier.uri | https://ir-library.ku.ac.ke/handle/123456789/28887 | |
| dc.language.iso | en | |
| dc.publisher | Kenyatta University | |
| dc.title | Physico-Chemical Parameters, Selected Heavy Metals and Nutrients in Water, Fish and Sediments from Lake Turkana, Turkana County, Kenya | |
| dc.type | Thesis |