Separation and Purification Technology, Vol.154, 301-308, 2015
Investigation of high-intensity magnetic hydrogels in the application of membrane physical cleaning
A newly synthesized magnetic hydrogel was applied to physical cleaning of low pressure microfiltration (hollow fiber) membranes. MC(50%)-90-3 h was chosen from several kinds of high-intensity magnetic hydrogels for its superior performance. According to the properties of the hydrogels, membrane filtration and cleaning tests was conducted under a orthogonal experiment with different factors and levels. An optimal combination of factors and levels was got as particle size of 5 mm, aeration intensity of 1 L/min and volume percent of 10%. The comparison of traditional aeration cleaning, backwashing and the hydrogels cleaning showed the superiority of the hydrogels with the IMP recovery of 93.07%. The results of shear stress detection showed that the outlet of membrane module received the lowest shear stress in corresponding with the most serious fouling. Therefore, a new cleaning method containing enhanced cleaning in position was created to make the intensive cleaning to the position with severe fouling. The recovery of TMP reached up to 96.62% after cleaning of the new method which indicated that reversible fouling can almost be removed completely. This good cleaning effect was hoped to provide support for further membrane physical cleaning. (C) 2015 Elsevier B.V. All rights reserved.
Keywords:Physical cleaning;High-intensity magnetic hydrogels;Optimal combination of factors;Shear stress;Enhanced cleaning in position