Assessment of Water Quality and Physico-Chemical Parameters of Omoku and Ikiri Rivers in Rivers State, Nigeria

Abstract

Introduction: Rivers provide the whole ecosystem with services that have attracted humans for several years. Water quality assessments serve as the foundation for effective water resource management, enabling the identification of impaired water bodies and informing the development of strategies to mitigate pollution and restore ecological health. Aim: The aim of this research was to determine the water quality and the physico-chemical parameters of Omoku and Ikiri Rivers in Rivers State, Nigeria. Study Design: The study used descriptive and observational methods with a variety of samples that were examined in a laboratory. Data from the two rivers designated for the study had to be noted, recorded, and described as part of this design. Methodology: Water samples were collected monthly from the two rivers for a period 12 months (February, 2023 to January, 2024) to determine the physico-chemical parameters of Omoku and Ikiri Rivers. This was achieved by collecting three replicate water samples from five Stations of Omoku River and one Station from Ikiri River (Control). They were analyzed in the laboratory using Standard Operating Procedures (SOP) methods. Result: The study revealed that Alkalinity of Stations 1 to 5 (Omoku River) ranged from 11.42 to 16.83 mg/L while the Ikiri River (Control) was much lower at 6.29 mg/L, suggesting less buffering capacity and possibly less pollution. For Total Suspended Solids (TSS), Stations 1 to 5 had a range of 16.8–18.9 mg/L, higher than control (4.09 mg/L), indicating more particulate matter in Omoku River. Chemical Oxygen Demand (COD) recorded in the study ranged from 5.12 – 6.17 mg/L in Stations 1-5 signifying moderate organic pollution. Control Station showed lower value (4.22 mg/L). Biological Oxygen Demand (BOD) in the five stations ranged from 1.30 – 2.14 mg/L, which indicated low to moderate pollution. Electrical Conductivity (EC) in the five stations recorded values between 28.44 and 33.04 µS/cm indicating low mineral content while control station was even lower (13.25 µS/cm), indicating fewer dissolved ions. For Total Dissolved Solids (TDS), Stations 1 to 5 recorded values from 14.17 to 16.29 ppm while Control station had 6.75 ppm indicating cleaner river water. Water temperature varied from 27.6°C – 27.9°C in all stations and control. The Salinity values of 0.02 - 0.03 ppt were recorded in stations 1 - 5 and corresponding with freshwater range though the Control station stood at 0.01 ppt, slightly purer. For Dissolved Oxygen (DO) in Stations 1 - 5 had values of 4.03–4.66 mg/L, slightly below the ideal >5 mg/L for aquatic life while Control recorded 5.81 mg/L, a healthier oxygen levels. In all the 5 stations, pH ranged from 8.51–8.82, slightly alkaline and the control had 8.38, closest to neutral. Turbidity at Stations 1 to 5 was 6.91 – 8.81NTU slightly above WHO’s <5 NTU recommended limit for portable water indicating reduced water charity and potential contamination risk. The control station in the other hand had a mean turbidity of 2.47 NTU which falls within acceptable limits and reflects comparatively better water quality. Conclusion: These findings underscore the urgent need for regular monitoring, pollution control measures, and sustainable water management strategies to safeguard water quality. Strengthening community awareness, enforcing environmental regulations, and implementing remediation efforts are critical to ensuring that the Omoku and Ikiri Rivers remain viable water resources that support both human livelihoods and ecological integrity.