| Abstrakt: |
Nowadays, reverse osmosis (RO) and nanofiltration (NF) membrane technologies are increasingly used for drinking water supply in small towns and settlements. One of the important tasks in the design and operation of a membrane plant is the correct choice of membranes type and their operation mode (permeate recovery, operating pressure, chemical cleaning intervals) to obtain standard quality water for a long time at minimal cost. The purpose of this research was to find out the dependences of some trace elements content in nanofiltration permeate on the mineral composition of the source water and the operating time of the membrane plant. The experiments were carried out on a laboratory unit worked in a circulating mode with gradual concentration of feed solution. The source water was modeled by adding solutions of the specified salts. Based on the experiments performed, the effect of the composition of the source water (the main salt composition) on the selectivity of membranes for fluorine and iron was established. Based on obtained dependence of scale amount accumulated in membrane module on the operating time, a prediction of a decrease in the selectivity of the nanofiltration membrane was done. A technique is proposed for predicting the quality of the NF filtrate over time, which will be useful in the design of nanofiltration plants. [ABSTRACT FROM AUTHOR] |
