The use of membrane filtration for removal of aluminum from drinking water sources

Abstract

Drinking water sources contain a range of natural or anthropogenic substances, which even in relatively small concentrations need to be removed in order to complete sharpening drinking water standards. Among them, aluminum is one of the elements, which can migrate to drinking water sources by means of elution from natural rocks, as a result of discharge of wastewater containing it or as a result of aluminum-based coagulation treatment processes. In Polish regulation, the permissible amount of aluminum in drinking water is established at 0.2 mg Al/L. On the other hand, in Poland, there appear natural water sources of excellent water quality, which, however, are characterized by elevated aluminum content. In this paper, the research on the removal of aluminum by nanofiltration and ultrafiltration combined with coagulation is discussed. The obtained results suggest that either nanofiltration or ultrafiltration combined with coagulation may be used for effective removal of contaminant from drinking water, regardless of its initial concentration (up to 5 mg Al/L for nanofiltration feed, and up to 18 mg Al/L for ultrafiltration feed), the permeate parameters correspond to drinking water quality standards. The selection between suggested processes depends on the final economic effect related to membrane fouling and cleaning procedures and frequency, the investigation of which has not been the subject of the presented research.