Title: Behaviors of dissolved organic matter in membrane desalination
 
Journal: Desalination
Authors: Sangho Leea, Jun-Seok Choia, Chung-Hak Leeb
Corresponding author: Sangho Lee
Institute:    a Department of Environmental Research, Korea Institute of Construction Technology, Gyeonggi-do, Korea
b  School of Chemical Engineering, Seoul National University, Seoul, Korea 

The original and creativity of paper: They studied the fouling phenomena of scale formation in the presence of dissolve organic matter (DOM). Interestingly, instead of synergistic effect, the presence of DOM during scaling formation can be reduced scaling formation.
 
Summary: 
In this paper, they studied the effect of humic acid on scale formation in RO membrane system. They performed fouling experiments using a laboratory scale filtration device and synthetic feed solution. According to this study, filtration data and image analysis results were obtained. The results will be explained as follows:

    Even though   DOM is one of foulants, however DOM can act like antiscalant by covering on the crystal growing site of crystal particles followed by retarding the rate of crystallization. 
-    Scale formation was greatly affected by DOM and there appeared to bea strong relationship between the rate of fouling and DOM concentrations. As the concentration of humic acid increases, the scale formation was retarded and higher flux was observed. 
    As the same as humic acid,  fulvic acid exhibited the inhibition effect on the crystal forming  as well. 
    The morphology of crystals grown in a presence of humic acid was observed.   Plate-like crystal particles were obtained at high concentration of humic acid. This plate-like crystal particles caused by adsorption of  humic acid on the active side of crystals particles                                  

     
Fig. 1 Effect of HA on the shape of CaSo4 crystal (magnification 200 times). (a) CaSO4 crystals formed without HA (b) CaSO4 crystals formed with HA (2 mg/L).
 
Application: The paper provides the fundamental of fouling mechanism of scale formation in a presence of dissolve organic matter. Since SWRO fouling is very complicate and hard to fully understand. Thus, it is very useful for students who studying on fouling mechanism to let them get more idea about fouling mechanism. 
  
By Monruedee Moonkhum
Email: moon@gist.ac.kr