Winery wastewater treatment: a practical guide for wine producers

Wine production is the beating heart of Italy’s agri-food industry. But behind every bottle lies a crucial technical challenge: managing winery wastewater. If you work in the wine sector, you know how important it is to approach this issue with expertise, foresight, and tailored solutions.

Winery effluents: a seasonal but strategic challenge

During harvest season, wineries generate the bulk of their annual wastewater. These are cleaning waters from vats, floors, equipment, and processing areas, with highly variable organic loads. Then, during wine transfers, volumes decrease. During bottling and packaging, discharges nearly disappear. On average, 70% of annual wastewater is produced between harvest and transfers.

For every 2,000 kg of grapes processed, approximately 1 m³ of wastewater is generated. Small wineries tend to use more water per quintal than larger ones—a key factor when designing efficient and scalable treatment systems.

What’s in winery wastewater?

Winery effluents are not toxic, but they contain high levels of organic matter:

• Sugars, organic acids, and processing residues
• Phenols and sulfites (from wine and lees)
• Surfactants and caustic soda (used for cleaning and sanitization)

The BOD₅/COD ratio ranges from 0.4 to 0.7, indicating good biodegradability. During harvest, COD levels can exceed 20,000 mg/L; in quieter months, they drop below 1,000 mg/L. These effluents are low in nitrogen and phosphorus, which often need to be supplemented (e.g., with urea and phosphoric acid) to maintain biological balance in treatment systems.

How to treat winery wastewater

An effective treatment system combines physical and biological stages:

1. Fine screening – removes skins, seeds, and coarse solids
2. Balancing and pre-aeration tank – homogenizes and stabilizes organic loads
3. Low-load activated sludge treatment – reduces odors and excess sludge
4. SBR reactor (Sequencing Batch Reactor) – adapts biological cycles to variable loads
5. Horizontal subsurface flow constructed wetland – final polishing, ideal for surface discharge or agricultural reuse

Every winery is unique: custom treatment required

There’s no one-size-fits-all solution. Your wastewater treatment system must be tailored to:

• Water volumes used
• Production calendar
• Type of wine produced
• Local environmental conditions and regulations

Like a tailored suit, the treatment system must fit your production needs perfectly—ensuring sustainability, efficiency, and environmental compliance.

From waste to resource: circular economy in the winery

Thanks to modern technologies, winery wastewater is no longer just a problem—it’s an opportunity:

• Treated water can be reused for irrigation
• Stabilized sludge can become agricultural soil amendments
• Organic residues can be sent to anaerobic digestion for biogas production

Smart wastewater management in wineries is not just a regulatory obligation—it’s a chance to innovate and make viticulture more sustainable. Investing in effective, customized treatment systems means protecting the environment, reducing costs, and unlocking hidden value.

Tell us about your production process: we’ll help you turn wastewater into value with efficient, scalable treatment systems aligned with circular economy principles.