Pilot studies on the river water treatment using coagulation-UF membrane filtration and direct UF membrane filtration

Abstract

The pilot tests of UF membrane filtration for river surface water were carried out with coagulation as a pre-treatment (test 1) and without coagulation (test 2). Both UF membrane filtrate water of the test 1 and the test 2 met drinking water quality standard in Vietnam. Additionally, the TMP and the filtration flow rate were kept stably during test periods without changes in operation conditions although the river water turbidity was varied due to heavy rain. It was indicated that the water treatment system can be simple by skipping coagulation and/or sedimentation as pre-treatments. The filtration flux of the test 1 and the test 2 were 138 L/m2 h and 93 L/m2 h, respectively. The flux was higher than the reported reference value indicating that the module number of modules required for the water treatment plant can be reduced by using the FG module. The test data of the test 2 was theoretically analysed by the equations based on Darcy’s low. The estimated TMP correlated highly with measured value (R2=0.71). The optimized parameters were used for the simulation of the operation. The simulation results indicated that the TMP before backwashing is increased around 35 kPa when the river water turbidity increased up to 500 NTU. It was indicated that the CIP interval should take into account the TMP increasing by turbidity variation.