Why high-strength industrial wastewater is increasingly treated as a resource rather than a cost factor

In 2026, industrial wastewater treatment is shifting noticeably – away from pure pollutant removal toward resource and energy recovery. For planners and operations engineers in the food, beverage and processing industries, this has concrete consequences for process selection. This article frames the market drivers and shows when anaerobic processes are technically and economically superior.

The market trend in figures

The food and beverage segment is the largest field of application for industrial wastewater treatment in 2026 – driven by high organic loads as well as fats, oils and suspended solids. It is precisely these properties that make the wastewater attractive for anaerobic processes: the anaerobic segment is growing faster than average because it combines two advantages – energy recovery in the form of biogas and significantly lower sludge production than aerobic processes. At the same time, the pressure toward water reuse is rising; in water-scarce regions, closed water-loop concepts are increasingly coming into focus.

The key terms

• COD (chemical oxygen demand): a measure of the organic load in mg O₂/l. The higher the COD, the more usable energy the wastewater contains.
• Anaerobic: breakdown of organic matter in the absence of oxygen; the end product is methane-rich biogas.
• Aerobic: breakdown under aeration; effective at low to medium loads, but energy-intensive.
• MBR (membrane bioreactor): biological stage plus membrane filtration; delivers very clear, reusable effluent.

When anaerobic, when aerobic?

As a rough guideline: from an influent COD of about 2,000 mg/l, anaerobic pre-treatment becomes attractive in both energy and economic terms, because the biogas yield increasingly covers the plant's own energy demand. Around 1 kg of degraded COD produces about 0.35 m³ of methane – equivalent to roughly 3.5 kWh of usable primary energy. Aerobic processes (activated sludge, SBR, MBR) remain relevant for polishing lower residual loads. In practice, the combination of an anaerobic high-load stage with aerobic or MBR post-treatment is often the most robust concept for high-strength food-industry wastewater.

What this means for each industry

Meat and slaughterhouse operations: slaughterhouse wastewater averages around 6,000 mg/l COD, and exceeds 10,000 mg/l in the influent to the in-house treatment – plus fat and suspended solids. A classic case for an anaerobic high-load stage with upstream flotation.

Dairies and milk processing: the mixed wastewater is around 3,000 mg/l COD; whey, a by-product of cheese-making, reaches 50,000–70,000 mg/l. High COD loads mean high biogas potential.

Beverage producers: wastewater from wine and sparkling-wine production reaches a COD of around 12,000 mg/l – a strong energy potential.

Biowaste recovery: here, wastewater treatment can be coupled with the recovery of organic residues – both feed the same anaerobic process.

The ROI logic in one sentence

Anaerobic processes cut costs twice over: disposal and wastewater costs go down, while usable energy is generated at the same time. The COD load is converted via the CHP unit into electricity and heat that can be used directly on site.

Calculating it concretely

How much energy is in your wastewater depends on the volume flow and the COD load. Our project calculator gives a rough estimate for your own operation – a first basis for the economic assessment. Industry-specific calculation examples can be found on the respective industry pages.