The study of the effectiveness of the removal of anionic natural organic matter (fulvic acids-FA and humic acids-HA) and inorganic anions (F-, Br-, NO3-) in MIEX®DOC process was performed. The influence of physico-chemical parameters of feed water on the process performance was investigated. The ion exchange process was carried out using strongly basic, macroporous polystyrene resin MIEX® by Orica Watercare. The synthetic feed waters differ in composition, i.e. concentration of FA and HA (ca. 6 and 12 mg/L), anions content (F-, Br-, NO3-) and of various alkalinity (ca. 20 and 120 mg/L as CaCO3) were used. The study confirmed the possibility of application of MIEX®DOC process for removal of anionic contaminants from water. It also showed the significant impact of feed water parameters on the process effectiveness. Moreover, the strong dependence of anions (F-, Br-, NO3-) removal, FA and HA concentration on the resin dose was revealed.
A number of inorganic compounds, including anions such as nitrate(V), chlorate(VII), bromate (V), arsenate(III) and (V), borate and fluoride as well as metals forming anions under certain conditions, have been found in potentially harmful concentrations in numerous water sources. The maximum allowed levels of these compounds in drinking water set by the WHO and a number of countries are very low (in the range of µg/l to a few mg/l), thus the majority of them can be referred to as charged micropollutants. Several common treatment technologies which are nowadays used for removal of inorganic contaminants from natural water supplies, represent serious exploitation problems. Membrane processes such as reverse osmosis (RO), nanofiltration (NF), ultrafiltration (UF) and microfiltration (MF) in hybrid systems, Donnan dialysis (DD) and electrodialysis (ED) as well as membrane bioreactors (MBR), if properly selected, offer the advantage of producing high quality drinking water without inorganic anions. I