Humic substances (HS) are hydrophobic parts of dissolved organic matter, which are hard to degrade using biological processes. When exposed to disinfection processes, the HS present in wastewater could lead to the formation of disinfection by-products (DBPs), which are harmful and dangerous to health. Thus, a chemical coagulation process is commonly used for HS removal. This work used a cylindrical galvanic cell (CGC) with an iron anode and a copper cathode, where the dissolution of the anode served as an alternative source of metal ions for HS coagulation. The galvanic cell current for CGC stabilized at around 0.6 mA, and the voltage fluctuated, ca. 0.5 V for all solutions. The peaks observed on cyclic voltammograms could be associated only with oxidation and dissolution of iron; no other process was identified. After the process, the structures and molecular composition of the anode surface suggest the loss of Fe mass and the formation of iron oxides due to corrosion. The initial pH of the tested solution influenced the total Fe concentration in the solution as well as colour and turbidity. The quantitative removal of HS by electrolysis and membrane filtration processes at initial pHi = 6.0 yielded 72% and 90%, respectively, after 6 and 10 min. The mechanism of sorption on the flocs of hydroxides as a primary factor in HA removal was suggested.

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.