When choosing a dairy water purification system, several factors to consider. First, a typical water treatment system may not handle peak demand, but a dairy needs a system that can handle high volume. The system should be able to reduce undesirable constituents to acceptable levels and meet the needs of the dairy throughout its useful life. The provider of the system should be able to guarantee these two conditions.

Dairy Water Purification Systems

Acidogenic

Acidogenic dairy water purification system are good for cleaning unbalanced milk effluents. Dairy effluents are acidic, containing 2.5 g/L CaCO3. The use of sanitizers to maintain the pH of the wastewater can help prevent contamination. Typically, dairy facilities use large amounts of chemicals to maintain the cleanliness of their production facilities. In many cases, spent lye is discharged as wastewater. By filtering this wastewater, the salts can be reduced and reused, which reduces the number of salts being discharged into the environment.

In a recent trial, an ambient temperature anaerobic reactor was used to treat real dairy wastewater at a milk processing plant. The reactors were designed to achieve COD removal efficiencies of 50 to 70% for total and soluble COD. The reactor biomass included stable populations of Methanothrix species, which represented up to 47% of the relative abundant active species in the wastewater. In the final test, the effluent from the process was of good quality.

Methanogenic

Methanogenic bacteria can be used for biogas production. The wastewater of dairy operations contains many compounds relevant to the biorefinery. These include lactose, lactic acid, acetic acid, and citric acid. Additionally, these wastewaters contain amino acids, organic acids, and volatile carbon compounds. The bacteria that can produce methane include Lactobacillus.

Reverse osmosis

Reverse osmosis is a highly effective method for water treatment. Reverse osmosis removes up to 99% of dissolved minerals, organics, and particles. This method utilizes a semi-permeable membrane and is the opposite of natural osmosis. The water passes through the membrane under pressure, creating a product called product water.

Anaerobic or hybrid processes are used to treat wastewater in dairy facilities. The two types have their advantages and disadvantages. Anaerobic processes are more cost-effective and produce less odor. The latter type is more appropriate for high-strength wastewater. The latter, on the other hand, uses high-pressure nozzles to minimize water consumption and maximize effluent recovery. Aside from eliminating turbidity and odor, these systems also remove phosphorus, nitrate, and nitrates.