DEVELOPMENT AND PERFORMANCE EVALUATION OF ALTERNATING CURRENT-DIRECT CURRENT DEVICE FOR ELECTROCHEMICAL TREATMENT OF WASTEWATERS

Abstract

This study presents a report on the performance of a locally developed power supply unit (alternating current, AC- direct current, DC device) for electrochemical treatment of water and wastewaters on a laboratory scale. The design of the power supply unit (AC-DC device) for electrochemical treatment of water and wastewater was based on the generation of 0 – 13.4 DC volts and 0 – 20 DC amperes from an AC source using a step-down transformer and 20 A diodes (as a full bridge rectifier. Output from the device was measured using standard analogue voltmeters. The effect of the input AC voltage supply on the output DC voltage of the device was studied. The results from the locally developed device were compared with output from two similar devices (a locally developed and a commercially available one). The results of the outputs from these three devices were analysed statistically using ANOVA, total error (Er²), coefficient of determination (C_D), and model selection criterion (M_SC). The study revealed that the Er², C_D and M_SC for the three devices were 27.215, 27.891, and 27.484; 0.090, 0.069, and 0.078; and -0.370, - 0.544 and -0.477, respectively. The study concluded that there was no significant difference between the DC output (F_{11, 44} = 1.2593 and p = 0.279) from the three devices. The inputs AC have substantial effects (F_{4, 44} = 1323.9 and p =3.0 x 10^-45) on the outputs of the three DC devices at a 95 % confidence level.