UPGRADING BPR BY ADDITION OF RAW AGRO-FOOD WASTEWATERS

The aim of this work was to study the feasibility of the dose of the agro-food wastewaters, generated in the nearby of the Ciudad Real WWTP (Spain), to enhance the biological phosphorus removal from the urban sewage. The main objectives were to select the best agro-food wastewater and to determine the optimum dose for their use in the full scale WWTP in order to fulfill the EU regulations. The biological phosphorus removal potentials of the agro-food wastewaters studied were always lower than that of the acetate. However, the dose of agro-food wastewaters raised significantly the phosphorus removal capacity of the urban sewage because of the significant increase of easily biodegradable substrates in the influent. The wastewaters from tomato and potato processing presented the highest phosphorus removal capacity. The addition of these agro-food wastewater to the urban sewage yielded a lower biological phosphorus removal potential than the typical obtained adding acetate, however the agro-food wastewater were originated from wastes so it was economical and environmentally sound.