Quantitative Assessment of Hazardous Inorganic Pollutants in Wastewater Sources: Implications for Water Quality and Environmental Health

Abstract

This study presents a quantitative assessment of hazardous inorganic pollutants in wastewater sources from four distinct locations A, B, C  and D within the study area in Ikot Ekpene city in Akwa Ibom State, Nigeria. The analysis focused on evaluating both physical  parameters—pH, temperature, dissolved solids (DS), suspended solids (SS)—and the concentrations of various ions, including heavy metals (Ca²⁺, Fe³⁺, Cu²⁺, Co²⁺, Pb²⁺, Cd²⁺) and anions (NO₃⁻, Cl⁻, SO₄²⁻, CO₃²⁻). Physical parameters revealed a pH range of 6.5 to 6.8,  indicating slightly acidic to neutral conditions. DS and SS values varied across locations, with the highest recorded at 10.6 mg/L and 4.4  mg/L, respectively, at location C, reflecting potential contamination. Heavy metal analysis showed notable variations among the locations.  The average concentrations of Fe³⁺ ranged from 1.373 mg/L in location A to 3.763 mg/L in location D, with the highest levels in  location C (3.594 mg/L), indicating potential industrial contributions. Lead (Pb²⁺) concentrations were highest in location D (2.231 mg/L)  and lowest in location B (0.9934 mg/L), exceeding the World Health Organization's (WHO) permissible limit of 0.01 mg/L for drinking  water, suggesting a health risk. Cadmium (Cd²⁺) concentrations varied, with a peak of 0.975 mg/L in location D, also surpassing WHO's  limit of 0.003 mg/L.Anion analysis revealed that nitrate (NO₃⁻) levels were highest in location C (80.919 mg/L), while chloride (Cl⁻) levels  were most elevated in location B (15.467 mg/L). Sulfate (SO₄²⁻) concentrations ranged from 12.779 mg/L in location C to 211.257 mg/L in  location A, highlighting differences in potential sources of pollution across the study area. Statistical analysis using ANOVA showed  significant differences (p < 0.05) in pollutant concentrations between locations, emphasizing spatial variations in contamination levels.  The findings indicate that some of the sampled locations contain hazardous pollutants at concentrations above recommended limits,  posing potential risks to human and environmental health. This study underscores the need for targeted wastewater management  strategies and continuous monitoring to mitigate the impact of industrial discharges on local water quality.