Reusing citrus wash water

Water is essential in agriculture. The development, production, and quality of the final agricultural product depend directly on this resource, and farmers know it. However, the importance of water does not end in the field, as it extends throughout the entire value chain and plays an essential role in the quality of the final product that reaches the consumer.

The excessive consumption of water in the post-harvest process is one of the sector's biggest concerns due to the environmental repercussions and costs it entails. In addition, there are other aspects that must be taken into consideration, such as the use of fungicides (Imazalil among others) that cannot be discharged along with residual waters. Control over these compounds and the associated fines have been increasing in recent years, which has affected many companies in the sector.

To reduce this water consumption, a leading Valencian company in the citrus sector started a pioneering project advised by Azud and Sanifruit: reusing water from its citrus washing processes.

It was impossible until we did it
This company had an ozone generator that it used to remove Imazalil from the water used to wash the fruits. However, the cost of the operation was very high because they needed to use a large amount of ozone to guarantee the complete elimination of the high load of suspended solids, BOD5, and COD that the waters had. This washing water contained dust, soil, silt, plant debris, and organic matter due to the rotting of citrus fruits, etc., so it was also unfeasible to reuse the water in the washing process.

The company, advised by Sanifruit, contacted Azud to design a washing water treatment line that integrated several stages to achieve the necessary water quality for reuse: decantation, filtration, refining, and disinfection.

The design of this solution took into account that the company staff would be in charge of the operation and maintenance of the plant, so the design was optimized so that inspection and maintenance could be carried out easily, without the need for qualified personnel.

The return on investment in this facility has taken less than 3 years and, due to the easy operation and great cost savings, they decided to carry out a second project to reuse their washing water in another of their processing centers.

In this second plant, the large use of reused water has allowed them to obtain a return on their investment almost immediately while achieving a much more sustainable water management and minimizing their water footprint.

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