One of the most critical sources of environmental issues in shopping centers is the food court, with its greasy wastewaters. Our long term experience and a conducted survey came to prove that the majority of malls and shopping centers have serious compliance problems with waters coming from grease traps. Since grease traps are designed to retain wastewaters for a certain period, often they generate bad odors and increase organic loads. These aﬀect the downstream treatment plant and are many times not complying with the reject limits established by local authorities. Thus, approaching solutions for shopping malls wastewater treatment is essential.
What do they do?
A major South American shopping mall, with dozens of restaurants in the food court and thousands of daily meals to prepare and serve, was facing the more and more compliance problems with local authorities, especially regarding COD and O&G limits. Besides, this shopping center was also struggling with bad odors coming from grease traps in the parking lot.
What are they trying to achieve?
Replacing standard and also sophisticated (with limited performance) grease traps by chemical treatment units, with ﬂotation devices (DAF). This change intends to give a proper chemical treatment to shopping malls waste water treatment, removing all solids, fats, and greases, avoiding bad odors, and reducing drastically its organic loads. At the end of the day, these wastewaters are to be prepared for a ﬁnal disinfection and filtration, which will allow them to be reintroduced into an internal feed line to ﬂush waters and irrigation.
Coming up with an efficient treatment solution for this shopping mall wastewaters, VentilAQUA brought to the process an advanced oxidation technology, called electrocoagulation and electro-oxidation. This wastewater treatment solution, based on electricity, allows a more intense and eﬃcient organic matter removal without chemicals, managing to reduce contamination to very low levels, and allowing to use common multimedia ﬁlters with longer lifetime. At the end of the day, thanks to the use of the oxidation technology in wastewater, the waters are ready to be reused.
Under one year’s payback time, the shopping mall observed a great reduction in water consumption. Around 90% of food court wastewaters were being recovered into ﬂushing toilets, thus reducing dramatically water consumption in toilet rooms. Moreover, there was an elimination of complex removal and trucking of liquid wastes and greases, which were always highly loaded, and carried an extremely high cost.