The authors regret that Figure 1 was incorrect in the online version of their paper and wish to apologise for any inconvenience caused. The correct version of Figure 1 is shown below:
Figure 1

Experimental setup (1: pressure gauge; 2: pressure regulator; 3: filtration cell; 4: magnetic stirrer; 5: weighing balance; 6: PC).

Figure 1

Experimental setup (1: pressure gauge; 2: pressure regulator; 3: filtration cell; 4: magnetic stirrer; 5: weighing balance; 6: PC).