Characterization of surfactant pretreatment on the fouling mitigationduring direct membrane filtration of waste activated sludge: Experimentalanalysis

In this research, surfactant supplementation was investigated as a promising strategy for fouling mitigation to improve wastewater membrane filtration process. To do this, the effect of wastewater pretreatment with three different surfactants of cationic CTAB, non-ionic X۱۰۰ and anionic SDS on membrane performance were investigated in terms of flux variation, membrane rejection and fouling mechanisms. According to the results, CTAB addition at an appropriate dosage improved membrane performance, while SDS and X-۱۰۰ showed a negative impact at all dosages. The optimum dosage of CTAB was achieved as ۳۰۰ mg/L in which the water flux increased from ۱۹۵ to ۶۱۱ LMH and the rejection rate decreased from ۹۳ to ۸۵%, respectively. The results revealed that increasing TMP from ۵۰ kPa to ۲۰۰ kPa reduced the optimum dosage of CTAB from ۳۰۰ to ۱۰۰ mg/L. Although, CTAB addition increased the total EPS amount from ۵۶.۱۶ to ۱۱۹.۶ mg/L due to the surfactant solubilization Property, the total resistance decreased from ۰.۳۳×۱۰۱۰ to ۰.۱۱×۱۰۱۰ m-۱ which was attributed to the flock formation through charge neutralization and bridging mechanism.

کلیدواژه ها:

Surfactant ، Membrane fouling ، Extracellular polymeric substance