Batch Electrocoagulation Reactor for Natural Organic Matter Removal from Synthetic and Real Water Samples

Abstract

The aim of this study was to evaluate the treatability of natural organic matters (NOM) from different origins-synthetically prepared humic acid solution and real water samples- by electrocoagulation (EC) process in batch mode using aluminium electrodes. Two main electrochemical EC parameters, pH and current density (j), were investigated. The removal efficiency of EC process was determined with respect to dissolved organic carbon (DOC) and UV absorbance at 254 nm. The initial pH (pH_i) and current density parameters were studied in the range from 4 to 7.3 and 0.4 to 4.5 mA/cm², respectively.

The highest treatment efficiency for humic acid (HA) was 87.5% (DOC treated 2.01 mg/L) at pH_i 4 with aluminium electrodes after twenty five minutes of process time. The short term best UV-abs-254% removal performance was obtained after 2 min at the same operation conditions. For Lake Saimaa samples, DOC removal was achieved as 71.1% with final DOC concentration of 4.29 mg/L and 86.2% UV-abs-254 removal was obtained after 25 min at pH_i 4 and at current density of 3 mA/cm². The results indicated that EC process is effective for the removal of NOM from water.