DEFINITION
Water is a key resource for many applications in the food manufacturing process, generally used as primary production, cleaning and sanitation, processing operations, and food ingredients. [1]
Processing operations can include: washing, brining, transport of products, dissolving ingredients, treatment of product (pasteurization or sterilization), ice manufacturing, steam generation, cooling process. [1]
Sources of water in industries are essentially: potable source (used generally in direct contact with food) and well, for other uses.
When water is used as a component of food or as an ingredient, it must be free from undesirable color, odor, taste, and impurities that can be harmful.
The Emerging Need for Water Reuse
In recent years, the global concern over water scarcity has become a central issue in international discussions. With growing populations, the impacts of climate change, and increasing demands from agriculture, industry, and domestic use, the strain on freshwater resources has intensified. On World Water Day, March 23, 2023, the UN highlighted alarming data about global water scarcity, emphasizing the urgency of the issue.
In this context, water reuse—or the use of treated wastewater—has emerged as a critical strategy for preserving water resources. Although not a new concept, water reuse has been practiced around the world for many years. Historical records show its use in Ancient Greece for irrigation through the disposal of sewage. Today, the growing demand for water has made planned water reuse a vital and contemporary topic.
Treated sewage now plays a fundamental role in sustainable water resource management, serving as a substitute for freshwater in agricultural and irrigation applications, among others. By reserving high-quality water sources for public supply and other priority uses, treated sewage helps conserve resources and adds an economic dimension to water resource planning. This practice reduces the demand on freshwater sources by replacing drinking water with lower-quality water where appropriate. This approach is already in use in some countries, based on the principle of matching water quality to specific needs.
Large volumes of drinking water can be conserved through reuse, particularly when lower-quality water, such as post-treated effluents, is used for applications that do not require potable water [2]. Internal reuse of water for industrial purposes is also on the rise, with water quality standards typically determined by the type of use and equipment specifications. However, the costs associated with implementing reuse systems and the availability of low-cost conventional water sources for irrigation remain significant barriers to wider adoption.
To promote water reuse, it is crucial to establish guidelines and conduct studies to define the specific characteristics water must have for various applications, whether agricultural, industrial, or recreational. Many companies are exploring water reuse for non-food contact applications, and some are even considering reprocessed water as a potential food ingredient. In both cases, thorough analysis is essential for safe use. However, ideological issues may arise: will reused water be socially accepted for food contact, and will people recognize its sustainability value, assuming safety is assured?
Promoting water reuse requires a combination of technological innovation, economic incentives, and public education to ensure its widespread acceptance and implementation. By addressing these challenges, we can move towards a more sustainable and resilient water future.
