Brewery Wastewater Management
Beer is about 95 percent water in composition; however, the amount of water used to produce a container of beer is far greater than the amount of water contained in the beer that is actually packaged and shipped out. In addition to the water used in production, wastewater generation and disposal is another concern with brewers. Most breweries discharge 70 percent of their incoming water as effluent. Effluent is defined as wastewater that is generated and flows to the sewer system. In most cases, brewery effluent disposal costs are much higher than water supply costs.
Sources of Brewery Wastewater
Brewery wastewater is usually voluminous with high moisture content. This wastewater usually has high chemical oxygen demand (COD) and BOD due to the presence of organic components (sugars, soluble starch, ethanol, volatile fatty acids). Its pH levels are variable and dependent on the amount and type of chemicals used in cleaning and sanitizing (e.g., caustic soda, phosphoric acid, nitric acid, etc.). Nitrogen (N) and phosphorus (P) levels present are also dependent on the handling of raw material and the amount of yeast present in the effluent. Some of these materials found in brewery wastewater are:
Wastewater is one of the most significant waste products of brewery operations. Water contributes directly as an ingredient to beer. It is used in wort production and for standardization to target alcohol content (as in high-gravity brewing). Some of the biggest water uses in a brewery include bottle and keg washing, cooling, pasteurization, CIP equipment, line and filler flushing water. Water is also used for boiler feed (i.e., steam rinsing).
Monitoring Wastewater Volume
It is highly recommended that wastewater volume be monitored and recorded throughout the year. Monitoring of wastewater volume is an essential tool in wastewater planning and management, as well as allowing measurement of water use in the brewery.
Discharge of Wastewater
Wastewater from a brewery may be discharged into either a waterway (rivers, streams, or lakes), directly into a municipal sewer system, or into the municipal sewer system after the wastewater has undergone some treatment. If discharged into a waterway, the brewery will more than likely be subject to the Clean Water Act’s National Pollution Discharge Elimination System (NPDES) permit program.
Publicly Owned Treatment Works
If the brewery discharges wastewater directly into a public sewer system, the publicly owned treatment works (POTW) will usually set limits on the composition, volume, rate of flow, temperature, and pH of the wastewater effluent. POTWs are designed to treat domestic sewage as well as wastewater from industrial users. Pretreatment regulations are in-place to control discharge of pollutants from industrial users that might pass through or interfere with POTW treatment processes, or that might contaminate sewage sludge.
Brewery effluents characterization is essential in order to limit variability in terms of a properly designed effluent management system, check proper functioning of an operational plant, or wastewater quality monitor after treatment. The most common parameters for wastewater characterization and control of the treatment system are detailed below:
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