Lemons are one of the best known products of Sicily. Eurofood in Sicily is a world leader in lemon juice, producing 22 tons per day. To ensure that its waste is disposed of properly, the company now has an industrial wastewater treatment solution that uses Xylem’s energy-efficient technology.
Given the high production capacity of Eurofood, the company needed to find a smart way to treat more than 3,000 cubic meters of wastewater every day. As can be imagined, the wastewater has a high level of acidity. This cannot be handled by the treatment plant of the municipality of Capo D’Orlando, where Eurofood is located. The municipality’s system is designed for 30,000 people, and is already stressed in the summer season. Eurofood needed to build its own industrial wastewater treatment plant.
In addition, the company wanted to maintain its high environmental standards. Giuseppe Ingrillì, the last descendant of the family that founded the company, and the current head of sales, explains: “The environment is part of our philosophy. We come from a family of farmers, and we know that only by taking care of the environment can you have trees that produce the citrus fruit that has made us unique in the world.”
State-of-the-art industrial wastewater treatment
Eurofood set out to build a treatment plant that was able to minimize energy consumption during periods of limited production and that met all environmental regulations. The wastewater from the plant includes water used to wash the outside of the lemons, clean the equipment, and wash and sterilize the bottles.
The company Manutambiente was contracted to construct the new treatment plant and adopt the most innovative and reliable technologies offered by the market.
“This could not have been done without the use of the solutions designed by Xylem,” says the owner Francesco Ingrillì, grandson of the founder. “Xylem offers a complete range of technologies for industrial wastewater treatment, some of which we were already using. We appreciate Xylem’s technical quality and local support. ”
First treatment step: lowering acidity
In the first stage of treatment, all wastewater is conveyed to a tank where the acidity is balanced. The wastewater is also screened to remove any solids, where a submersible Flygt NP 3127 MT pump is used. Although the drains may contain fibers or rags, the non-clog design of the Flygt pump ensures that the treatment process is not interrupted.
The second step: biological treatment
Bacteria are used in the biological treatment step and require an environment with the right amount of acidity and oxygen. Rather than using one large tank, to save costs and energy two tanks were used, with 2,500 m3 capacity each.
In the low load phases, the bacteria are only found in one of the tanks. When an increase in load is expected, the bacteria are transferred by a submersible Flygt NP3085 pump to the second tank. This non-clog pump is designed to save energy and can handle up to 15 liters of slurry per second.
Maintaining the right amount of oxygen
The biological treatment step can use a lot of energy compared to the other steps. The bacteria need an adequate amount of oxygen at any depth, however, providing too much oxygen could increase energy use and costs. The bacterial activity also varies depending on the weather, which can vary significantly in Sicily.
To optimize oxygenation, Sanitaire diffusers from Xylem were installed on the bottom of each tank. These diffusers produce micro-bubbles that evenly distributes oxygen throughout the slurry. The tanks were also equipped with a submerged Flygt mixer. Its three slowly rotating blades allow the waste to be constantly mixed, thus preventing sediment while ensuring that energy consumption is minimized.