Performance evaluation of combined Ultrasonic-Persulfate Processes in Organic Matter Reduction of synthetic Dairy Wastewater

Among the industries the dairy of the industry to recognize one of the most polluting Sources due to the presence of a high percentage of organic matter in the effluent. Recently, advanced oxidation processes, including Ultrasonic-persulfate with production of free radical such as sulfate and hydroxyl radicals is the efficient processes in wastewater treatment. Therefore, the aim of this study was evaluation efficiency of US-persulfate processes in treatment synthetic dairy wastewater. This research was an experimental-laboratory study. In this study, dry milk was used to make synthetic dairy wastewater and effect of pH (3, 5, 7, 9, 11), persulfate concentrations (50, 100, 250, 500, 750 mg/L), contact time (10, 30, 45, 60, 90 min) and intensity of waves US (35, 37, 130 kHz) was investigated on efficiency and the process efficiency was measured by calculating the residual chemical oxygen demand using spectrophotometrically at a wavelength of 600 nm. According to the results, the efficiency increased by decreasing the pH value, increasing the concentration of hydrogen peroxide to an optimal level and increasing the contact time and ultrasound intensity and also was found that the efficiency of US-persulfate process at pH 3, concentration of persulfate500 mg/L, intensity of US 130 kHz and contact time 60 min had the highest efficiency that the amount of this efficiency was 74/53% and 61/1% for synthetic dairy wastewater and actual dairy sewerage respectively.  According to the results, the acoustic-activated peroxylate process can be a good and high-performance method for removing organic matter from dairy wastewater.