Performance of combination of treatment processes for food industry wastewater depuration

Food industry uses large amounts of water for various purposes, including refrigeration and cleanliness, as raw material, as sterile water for food, transportation, cooking and dissolution auxiliary water etc. In principle the water used in the food industry can be recycled as process water and cooling or boiler feed water. As a consequence of diverse consumption, quantity and composition of wastewater from food industry ranging significantly.The effluent characteristics consist in SST large quantities, several chemical forms of nitrogen, fats and oils, phosphorus, chlorine and organic matter. Generally, BOD5 and COD of wastewater food industryare10 or even 100 times higher than municipal wastewater. Odours are also a typical problem. In the present study, a combination of more treatment step processes was investigated at real scalefor wastewater from food industriesby employing a flotation, biological, advanced oxidation and ultrafiltration process.A process data collection was performed and integrated with a characterization of the process effluents in terms of treatability and reusability. In order to evaluate properly the wastewater loading, an analysis course was set. It was examined the efficiency of the pollutants degradation by analysing the parameters concentration of the usual contained organic compounds in effluents: chemical oxygen demand (COD), ammonia, nitrites, nitrates, surfactants, which have been 15 20% extra degraded by mixed aeration. COD decrease resulted in the integrated air-ozone aeration process up to 90% compared to only 75% that occurs in a conventional biological activated sludge process. Further membrane MBR ultrafiltration and ozonation entailed a values reduction from another 10 -15%.