Solutions for water recycling in horticultural products

In this context, VAM WATERTECH offers solutions for the purification of up to 100% of the water from fruit and vegetable processing (Figure 1). For this purpose, it offers a wide range of purification techniques to create a unique solution adapted to the specific needs of the customer and the crop: potatoes, carrots, beetroot, salad, apples and pears. It is an intelligent solution that allows the system to work autonomously and save up to 95% of water consumption in the industry. Vam WaterTech's modular solutions are suitable for small to large industries, including major fruit and vegetable processors and packers in the Netherlands, Germany, Switzerland, France, England, USA and Canada, among others. The case of carrot cultivationCarrot cultivation is confronted with a wide range of diseases with serious consequences. The fungus Alternaria dauci, for example, can wipe out 80% of a crop. The fungus Pythium can even completely eradicate the crop. Other diseases, such as Sclerotinia sclerotiorum and Rhizoctonia, produce a persistent white, mouldy mycelium. Moreover, these micro-organisms can be active both in the field and during storage, before washing the carrots. Why does this happen?During the harvesting of carrots, a relatively large amount of soil containing spores and fungi is collected. Therefore, storage and handling at low temperatures is necessary for effective disease control. In general, carrots are stored almost immediately after washing and transported to supermarkets as quickly as possible so that the micro-organisms present do not have a chance to develop. However, if they are not cleaned properly or are washed with contaminated water, the cooling process becomes ineffective and favours the development of all kinds of fungi and bacteria (Figure 2). Carrots have a unique washing processThe washing process of carrots is different from that of e.g. potatoes as they require a higher volume of water to remove all adhering soil. Therefore, a higher residue load is introduced and more water circulation is required. If this is carried out in conventional water tanks or sedimentation pits, these must be relatively large and with considerable soil drainage capacity. In practice, the volume of the tanks is often too small and does not allow sufficient suspended matter to be captured. Also, they fill quickly with soil and are often open, which compromises water quality. In addition, the biological pollutant load (expressed as BOD and/or COD) in the carrot wash water is higher than in the potato wash water. Especially, when carrots are polished with brushes. This higher load leads to a higher bacterial pressure in the water, and therefore harmful substances can accumulate. To counteract this, aeration is necessary to promote the decomposition of the pollutants and to meet the requirements for discharge. Clean wash water reduces the concentration of micro-organisms in the carrots. However, rinsing with potable water is not sufficient: some sand and clay are removed, but the quality of the water used in the process leaves much to be desired. SolutionsVAM WATERTECH offers a practical solution to all these problems. With the VAM solution, the wash water does not have to be replaced every time. The components of the washing line remain cleaner because (contaminated) dirt does not accumulate and stick to them. The VAM water treatment system removes inorganic sludge and can be cleaned and disinfected regularly and effectively, even daily if necessary. It also requires less maintenance due to less wear and tear on the rotating parts of the washing line. It is a closed circuit so there is no spillage. Biological water treatment works most efficiently when the soil has been removed. With the removal of any suspended particles, part of the BOD, N and P can be captured. Sand and clay are removed, which reduces wear and tear on the washing installation. The separated sludge solidifies and can be deposited back into the soil. The sedimentation tanks can be replaced by a treatment plant that occupies much less (expensive) square metres, which means that the soil can be freed up and allows for a possible expansion of production. The VAM WaterTech system allows water to be reused in the washing process and for polishing the carrots. The water in the cooling systems is kept clean so that the products can be cooled more efficiently. The storage time after washing is extended, which is beneficial for the continuity in the delivery of your product. In short, VAM WaterTech systems ensure correct water quality and save millions of litres in a short time, without compromising hygiene. With this information, VAM WaterTech sponsors the article "Control of sanitisers in process water". Figures1. Percentage reduction of bacteria and spores with the VAM WaterTech air purification system.2. Carrot conditioning and washing lines