Breweries commonly contribute which combination of wastewater characteristics, often requiring equalization?

• A. Low BOD and low TSS with neutral pH
• B. High BOD (1000-4000 mg/L), high TSS (200-1000 mg/L), nitrogen 25-80 mg/L, pH 4-12
• C. High BOD but low TSS and very stable flow
• D. Only high nitrogen with no organic load

Answer: (B)

Breweries produce wastewater that is both very strong in organic matter and solids and highly variable in composition and flow, so equalization is needed to smooth out these fluctuations before treatment. The high BOD indicates a large amount of organic material that consumes oxygen; values in the 1000–4000 mg/L range show a strong load. The elevated suspended solids, with TSS around 200–1000 mg/L, come from spent grains, yeast, hops, and cleaning residues. A wide pH range, from about 4 to 12, reflects acids and bases used in cleaning and processing, which can stress downstream operations. And since production is batch-based with CIP cycles, flow and load can swing dramatically, making a common basin to blend and even out concentrations essential. Equalization helps prevent shock loads, protects treatment efficiency, and provides a more consistent influent for subsequent treatment steps.

The other options don’t capture this combination. They either describe a weak organic and solids load, or miss the wide pH range, or ignore the variability in flow and load, which are all characteristic drivers for needing equalization in brewery wastewater.