Dr. Stefanie Tömmers of ADI Systems Asia Pacific presented a paper on the anaerobic treatment of dairy wastewater at the New Zealand Trade and Industrial Waste Forum held recently in Hamilton, New Zealand.
Stefanie discussed issues related to the expanding dairy industry, including increasing loads to industrial wastewater treatment plants and the need for additional power and process water. With changing environmental standards and discharge requirements forcing the industry to upgrade its treatment systems, adding anaerobic digestion can reduce the load to an existing treatment system, improve effluent quality, and enable energy recovery from the organic matter in the effluent.
In the anaerobic treatment process, the majority of the organic matter (COD and BOD) and solids (TSS) is digested, reducing the need for further treatment. An energy-rich biogas is produced, along with a small amount of waste biomass (sludge). The biogas produced can be used as a heat resource for the dairy process or can be fed into a generator to produce electrical energy. In addition, solids and fats are reduced within anaerobic digestion, reducing the load to subsequent processes. With more efficient treatment, the effluent is more likely to meet regulations for discharge into waterways, and it is more feasible to recover the wastewater for reuse in the dairy process.
The ADI-BVF® reactor is a long hydraulic residence time anaerobic digestion technology that provides a simple, efficient, low maintenance method of treating dairy wastewater. This technology has been successfully treating the wastewater at many dairies around the globe with several of them using the biogas to fuel boilers and generate electricity in-plant.