Synthetic Textile Wastewater Treatment using Potassium Ferrate(VI) - Application of Taguchi Method for Optimisation of Experiment

The article attempts to assess the usefulness of the Taguchi method to optimise the purification process of synthetic textile wastewater (pH 6.7 - 7.2, Conductivity = 6.71 - 6.84 mS/cm, Salinity = 3581 - 3648 mg NaCl/l, Colour = 560 - 4710 mg Pt/l, COD = 2220 - 2290 mg O-2/l, TOC = 394 - 551 mg/l) using K2FeO4. The research was conducted using 3 types of wastewater containing, anionic detergent (sodium laurel sulfate, 100 mg/l) and differing only in the concentration of azo dye Acid Green 16 (AG 16). Technical K2FeO4 was used as an oxidiser, which was subjected to physico-chemical analysis (purity, UV-VIS spectrum, surface characteristics and chemical composition using SEAT and EDX methods). For planning and optimising the wastewater treatment process, the Taguchi method was used for four input parameters: pH (2, 7, 12), reaction time (10, 30, 50 min), AG 16 concentrations (20, 120, 220 mgl) and K2FeO4 concentrations (25, 125, 225 mg/l), for which 9 experiments were performed in accordance with the plan adopted. Test result analysis allowed to indicate the optimal values for individual input parameters (pH 2, time = 50 min, AG 16 = 20 mg/l, K2FeO4 = 125 mg/l). Under these conditions, visual discoloration of wastewater was obtained (AG 16 = 0.4 mg/l, down arrow 98%), colour removal (66 mg Pt/l, down arrow 88%) and DOC (249 mgl, down arrow 37%).