The removal of oil from water is of increasing importance in many industries, such as oil and gas, petrochemical and food industries, because of the large volumes of oily wastewater they produce. The aim of this work is to evaluate and compare the performance of ferrous and aluminium sulfate coagulations and to compare between sand filter, coagulation and a hybrid coagulation/sand filter process when used as pretreatment options. When the concentration of oil was low in the oil-water emulsion, the treatment by sand filter alone was adequate (oil ≤ 50 mg/L). On the other hand, when the oil concentration was greater than 50 mg/L, advanced treatments such as coagulation are required as post-processes to reach good water quality. Aluminium sulfate was observed to be more efficient (about 5% to 7% higher than the use of ferrous sulfate) and less costly than ferrous sulfate to remove oil from oil-water emulsion using coagulation. The optimal technology for pre-treatment to remove oil from oil-water emulsion was found to be a coagulant dosage of aluminium sulfate combined with sand filter at pH 8 during various concentrations as hybrid. Optimal conditions were found to occur at mixing duration and speed of 120s and 250 rpm respectively.

Many industries produce oil-water emulsions as major waste streams, which require specialised treatment, including the petrochemical, oil and gas and some food industries. One method to remove oil droplets from wastewater is using ceramic tubular microfiltration membranes. However, such membranes are vulnerable to fouling, which causes operational impairment. The aim of this work is to reduce ceramic membrane fouling by exploring the combination of ceramic membranes with several pre-treatment options. We have compared direct oil-water emulsion treatment using a ceramic microfiltration (MF) membrane with a hybrid system of coagulation/ sand filtration pre-treatment prior to ceramic membrane MF. Superior permeate flux was obtained using the hybrid coagulation/sand filter-MF process due to a reduction of membrane fouling by reducing the oil concentration in the inlet emulsion to the ceramic membrane. Moreover, the oil removal efficiency for hybrid coagulation/sand

Oil-water emulsions are one of the most serious pollutants because of the large quantities produced by various industries, such as the petrochemical, oil and gas industries. One of the major methods to remove oil from wastewater is filtration using ceramic tubular microfiltration membranes. However, such membranes are vulnerable to fouling, which causes operational impairment. The aims of this work are to study the influence of membrane pore size on permeate flux and oil removal efficiency at different operating parameters and the reduction in fouling when used in combination with hybrid Coagulation/sand filter-MF pre-treatment process. The droplet size of the oil-water emulsion has an interaction with the pore size of the ceramic membrane. Therefore, each pore size may be optimal, depending upon the concentration of oil in the emulsion, and hence droplet size. Steady-state flux and oil removal efficiency were found to b highest for hybrid coagulation/sand filter-MF due to a reduction of membrane fouling by reducing the oil concentration in the inlet emulsion to the ceramic membrane.