Characterization and treatment of a petrochemical wastewater for reuse
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Saudi Digital Library
Chracterization and treatability studies on a bench scale were carried out for the petrohemical wastewater of Saudi Petrochemical Company (SADAF) at Al-Jubail, Saudi Arabial. During wastewater quality survey, hourly samples were collected for the phosphate stream and the final effluent of the plant. The results of the analysis indicate that the wastewaters are low in organic content but variable in concentrations. The average total organic carbon for the phosphate stream and the final effluent were 73 mg/L and 65 mg/L, respectively. Batch scale granular activated carbon adsorption studies conducted on phosphate stream wastewater indicated that low values of initial pH and temperatures are favorable for adsorption. A nonadsorbable portion of organics was found to be ubiquitious to this specific wastewater. Bench scale ozonation studies were also conducted by varying the experimental conditions such as, detention time, gas flowrate, initial pH and temperature. The maximum reduction in terms of total organic carbon was 32.5 percent at a pH of 11.4 and temperature of 60?-C. The experimental data fitted well to a first order equation. Furthermore, the combined ozone/activated carbon was found to remove upto 81 percent of total organic carbon from the phosphate stream wastewater. Biological treatment of the final effluent in sequencing batch reactors (SBRs) removed 94 percent of biological oxygen demand. The optimum total suspended solids concentration was less than 5 mg/L for the effluent of SBRs. The introduction of fill and anoxic react periods into an SBR cycle was found to improve the quality of the biologically treated effluent.