Submerged microfiltration coupled with physcio-chemical processes as pretreatment to sea water desalination

Abstract

A B S T R AC TIn this study, the critical fl ux of the submerged membrane system was experimentally evaluated when it was used for seawater with and without pre-treatment. In this study, different processes such as fl occulation with ferric chloride (FeCl 3 ) and different doses of PAC adsorption were used as a pre-treatment. The pretreatment of fl occulant of 2 mg/L of FeCl 3 and adsorption with the dose of 1 g/L PAC showed an improvement in the critical fl ux from 5 L/m 2 .h to 6.7 L/m 2 .h and 13.3 L/m 2 .h respectively. The performance of these pretreatments was also determined in terms of modifi ed fouling index using ultrafi lter membrane (UF-MFI). UF-MFI and SDI indicated that PAC adsorption was a better pretreatment than fl occulation for the seawater used in this study. Molecular weight distribution (MWD) of seawater organic matter was also examined after different pretreatments. MWD of the raw seawater was mainly in the range from 1510 to 130 Da. It is observed that FeCl 3 fl occulation and PAC adsorption as pretreatments partially removed the organic matter of 1510 Da and 130Da respectively.

Techno-economical approach of GAC and microfiltration as a coagulant-free pre-treatment of seawater desalination

“…Since it was previously suggested that the combination of membrane fi ltration with an activated carbon pre-treatment could be a promising improvement of the fi ltration performance (especially concerning the removal of organic matter [6,7]) it was decided to technically explore this method as well, again without coagulation, as a comparable case for the stand-alone MF.…”

Recovery of resources from industrial wastewater employing electrochemical technologies: status, advancements and perspectives

“…There are mainly three types of physical methods [Y. 47 ; 48 ], (1) Flow equalization: It is used to enhance the efficiency of secondary wastewater processes by flattening out operation characteristics like pollutants levels, temperature, and flow over a period [R. 49 ]. (2) Sedimentation: It is often known as settling, is the removal of particulate matter, grit in the primary settling basin, and the flow of chemicals when the chemical coagulation method is used [ 50 ].…”

“…Electrodialysis is a process of electrochemical separation technique in which anions and cations are transported in an electric field across an ion exchange membrane [ 82 , 49 ]. Ions with positive charges are pushed to the cathode, and ions with negative charges are moved to the opposite side of the anode.…”

Physico‐Chemical Processes

“…Air sparging improved the filtration flux at lower suspension and at lower air velocities and this enhancement depended on the size of the particles (Hwang and Wu, 2009 A study showed that PAC pretreatment was more efficient than flocculation-coagulation pretreatment for the seawater in terms of MFI-UF and silt density index (Zhang et al, 2009e). Another research showed that the addition of PAC could reduce the impact of fouling effect of high algae due to seasonal variation of algae numbers in surface water (Kweon et al, 2009).…”