In order to practically use the acornic acid process for treating heavy metal contained wastewater, the pilot plant of 2.4 ton (wastewater)/day capacity was designed, constructed and operated. An electroplating wastewater originated from a company was treated with NaOH, acornic acid (60 ppm) and salt (1000 ppm) in this pilot plant. The COD, Cr, Fe and Zn cocentrations of treated water were 123, 0.08, 0.05 and 0.08 ppm, respectively. These values were all satisfied with the legal effluent limits. (Author).