Characterization of Produced Water from Hydrocarbon Terminals

Produced water is the largest volume of waste generated during oil and gas production. It contains a complex mixture of organic and inorganic contaminants, including hydrocarbons, salts, and heavy metals, which pose significant risks to environmental and public health. This study focused on the characterization of produced water from three hydrocarbon terminals in the Niger Delta region of Nigeria. Samples were collected and analyzed to determine physical, chemical, and heavy metal parameters, including pH, turbidity, electrical conductivity, total dissolved solids (TDS), biological oxygen demand (BOD₅), chemical oxygen demand (COD), total oil and grease (TOG), and heavy metals such as lead, mercury, and cadmium. A freshwater sample was used as a control. Analytical methods included gravimetric analysis, titrimetric procedures, spectrophotometry, and atomic absorption spectroscopy. Statistical analysis, including ANOVA, was applied to evaluate spatial variations and significance across sample sites. The findings revealed that while parameters like pH, TDS, EC, and salinity were within regulatory limits, others such as turbidity, COD, BOD₅, and TOG significantly exceeded permissible thresholds. Heavy metals including lead, zinc, barium, mercury, and cadmium were also found in concentrations far above acceptable limits, especially in Sample C. ANOVA results showed statistically significant differences among measured parameters but not among sampling locations, indicating consistent contamination across terminals. These findings emphasize the need for customized, multi-stage treatment systems to address diverse pollutant profiles. This study contributes to understanding produced water characteristics in Nigeria and supports regulatory compliance, treatment design, and improved environmental management strategies in the oil and gas sector.