The comparison between two methods of membrane cleaning to control membrane fouling in a hybrid membrane photobioreactor (HMPBR).

In this study, the effect of two membrane cleaning methods, such as aeration and addition of granular particles in a hybrid membrane photobioreactor (HMPBR) including Spirulina sp. with the concentration of 1.5 g·L was investigated. Three different spargers [i.e., different diameters of orifice (): 0.5, 1, and 1.5 mm] and granular particles (i.e., three packing ratios of 0.5, 1, and 1.5%) were used. The results showed that with the increase in granular packing ratio, / decreased significantly. The best result was achieved by combining aeration with an orifice diameter of 1.5 mm and a granular packing ratio of 1.5%, which led to the lowest / value (0.38), while / value with a of 1.5 mm was 0.68 without particles. In contrast, the ratio of pore blocking resistance to total resistance (/) increased by 4.2% under the combined application of 1.5 mm of orifice diameter and 1.5% of granular packing ratio. The results from protein concentrations in the cake layer showed that as the d became larger, cake protein concentration decreased by 40%, whereas increasing the granular packing ratio from 0.5 to 1.5% increased protein concentration by 60% in the cake layer.