DETERMINATION OF SOME INORGANIC CONSTITUENTS AND TREATMENT OF ELOBEID PETROLEUM REFINERY FEED WATER

The aim of this study is determination of some inorganic constituents of Elobeid petroleum refinery feed water before and after treatment. Four samples of feed water were collected for this study, three samples from refinery wells; (A, B, and C) and one sample from Bara Basin (D). The Parameters were analyzed include; temperature, pH, electrical conductivity (EC), total dissolved solids (TDS), total hardness (TH), total alkalinity (TA) total iron (TI), total suspend solid (TSS), total solid (TS), major cations (Na+, K+, Ca++ and Mg++) and anions (F-, Cl-, SO4-2, NO3-, NO2- and PO43-). The heavy metals content of Bara Basin water were analyzed by using atomic absorption spectrometer. The results showed that the temperature values ranged from 25-28.3ºC and after treatment from 22.2-28.2ºC within acceptable limits. pH values from 6.7 to 7.4 and after treatment from 6.5 to 6.9 all samples in agreement with permissible level reported by World Health Organization WHO and Sudanese Standards and Metrology Organization SSMO. Electrical conductivity (EC) for all samples between 638.0 to 1075µs/cm and after treatment between 105.4 to 432.2µs/cm except samples A and C were out of permissible limits before treatment. The total dissolved solids (TDS) values for all samples ranging between 319.3 to 548.75mg/l and after treatment between 53.80 to 93.15 mg/l. All water sources within specifications of WHO an SSMO. The concentrations of sodium (Na+) arranged between 11.5 to 17mg/l and after treatment between 0.0 to 0.1mg/l. All samples are below the permissible drinking water levels of WHO and SSOM (20 to 200 mg/l). The concentrations of Potassium (K+) was 0.48 mg/l and after treatment was 0.23mg/l in Bara Basin sample. Calcium (Ca++) ranging from 64.1 to 147.7mg/l and after treatment from 5.5 to 6.8 mg/l. All samples showed low concentration levels of calcium below the permissible drinking water levels of WHO 200mg/l. Magnesium (Mg++) concentrations levels, ranged between 30.8 to 69.11 mg/l and after treatment 4.3-2.2 mg/l. Fluoride concentrations range of 0.76 to 0.88 mg/l and after treatment 0.25mg/l to 0.48mg/l almost all samples within the permissible limits. Chloride ranges from 36.3 to 166 mg/l and after treatment from 16.3 to 66.7 mg/l almost all samples are within permissible limits. The Sulphate concentration was observed between 42 to 102 mg/l and after treatment between 17 to 46 mg/l all samples within acceptable limits. Nitrate concentrations between 0.75 to 24.4 mg/l and after treatment between 0.22 to 3.7 mg/l. That means all samples within acceptable limits of WHO and SSMO. The Nitrite concentrations between 0.00 to 1.36 mg/l and after treatment between 0.00 mg/l to 0.32mg/l within acceptable limit WHO and SSMO. Phosphate concentrations between 0.20 to 3.92 mg/l and after treatment between 0.00 to 0.87 mg/l most samples within acceptable limits of WHO. In Bara basin water the concentrations of heavy metals; Barium (Ba), Manganese (Mn), Copper (Cu), Zinc (Zn) and Chromium (Cr) were (0.13, 0.01, 0.03, 0.01 and 0.006) within acceptable limits of WHO (0.13, 0.08, 2.0, 4.0 and 0.05) respectively. With exception of Nickel (Ni), Cadmium (Cd) and Lead (Pb) were (0.24, 0.02 and 0.27) higher than the permissible limit of WHO (0.07, 0.003 and 0.01) respectively.