ABSTRACT
Produced water (also called formation water, brine or saltwater) is water from underground formations that is brought to the surface during oil or gas production and contains impurities that are harmful and detrimental to man and the environment when disposed from production platforms, both onshore and offshore. The disposal of this waste produced water in the Niger Delta has polluted land and water, causing damage to fisheries and agriculture, sabotaging human rights to adequate standard of living. The practice is often to treat the produced water before it is disposed to avoid public health issues for humans that could use the water from water bodies where produced water has been disposed. The pollutants in produced water range from Heavy metals, dissolved solids, dissolved oil, dispersed solids, dispersed oil, excess salinity etc. Some of the processes used in the treatment of produced water are in general, the gravity-based floatation separation, filtration-based separation techniques and biological process. Produced water sample gotten from an oil field in the Niger Delta region was tested for concentration of harmful impurities, total dissolved solids (TDS), total oil and grease (TOG), total suspended solids (TSS) gotten to be 1700mg/L, 0.71mg/L, 263mg/L respectively before treatment and 600mg/L, 0.5mg/L, 17mg/L respectively after treatment and then compared with the discharge limitation by the Department of Petroleum Resources which are 2000mg/L, 100mg/L, 30mg/L respectively for inland discharge and 5000mg/L, 100mg/L, 50mg/L respectively for offshore discharge. Filtration and n-Hexane Solvent extraction were the methods used in treating the produced water sample for TDS & TSS and TOG respectively and the EDTA titrimetric method for determination of Hardness, which had varying effectiveness, 65% for dissolved solids, 93% for suspended solids and 30% for total oil and grease. Alternate methods can be employed in improving effectiveness and successive repetition of the extraction and filtration process can improve overall treatment efficiency.
