Dairy wastewater treatment plant design

As already discussed in a previous article, there are multiple discharge options available for treated dairy effluent. As a short summary, you can discharge to the public sewer, discharge to the environment or reuse your wastewater. Depending on your discharge route, you will have different cleaning standards to achieve. Correct process selection to remove these specific parameters is necessary for success with dairy wastewater treatment plant design. For a recap on dairy effluent discharge options please read more here. 

The range of pollutants in dairy wastewater varies significantly based on the product being produced. Some pollutants are soluble and some are insoluble. Pollutants and substances that are not dissolved in the wastewater can be removed by physical screening steps and separation technologies such as dissolved air flotation. However, to remove soluble pollutants such as nitrogen and ammonia, biological treatment of dairy wastewater is necessary. Below we will discuss the main treatment steps along with the pollutants they remove. 

Physical screening of wastewater is often the first pre-treatment step used in industrial wastewater treatment. Physical wastewater treatment is generally used to remove coarse or large insoluble particles from the wastewater. Screening protects downstream equipment from large particles that can block pipes and accumulate in downstream tanks. Screening is therefore an important step in dairy wastewater treatment plant design. The screen selection depends on the composition of the wastewater. Where very high concentrations of fat are present, typical of cheese processing, then an internally fed drum screen pay be selected with an automatic hot wash. In contrast, where the process water is mainly liquid with a lower pollutant load from milk processing, then a simpler screw screen may be used. Mechanical screening and pre-treatment of dairy wastewater can remove fat, total suspended solids [TSS] and some BOD and COD from dairy wastewater. But the percentage removal rate is normally low. 

Declaration of conformity

Screened wastewater is generally collected in an equalisation tank to balance daily hydraulic peaks of wastewater production. From here, how the wastewater is handled depends on the discharge route and on the composition of the dairy wastewater. 

For wastewater with a very high fat content, or a very high concentration of suspended solids, pressure release dissolved air flotation system is necessary in the dairy wastewater treatment plant design. This is because other process steps including biological wastewater treatment of dairy wastewater cannot handle very high suspended solids or fat content in the wastewater. So for these wastewater types a pressure release DAF is necessary. 

A pressure release dissolved air flotation system is a highly efficient cleaning step. When discharging dairy effluent to the public sewer, it is normally possible to meet all of the required cleaning values with this cleaning step only. This allows for a simple dairy wastewater treatment plant design. 

Due to our extensive experience in the dairy sector, we have an optimised pressure release dissolved air flotation system designed and optimised specifically for the dairy industry. 

We can achieve incredible cleaning efficiencies: 

ClearFox® FBBR

For wastewaters that do not have a high amount of fat or suspended solids, it is possible to consider biological treatment of dairy wastewater. A biological treatment step can be considered as an add on process step after a pressure release dairy dissolved air flotation system, or it can be used as a standalone wastewater treatment process if the wastewater composition is suitable. 

Biological dairy wastewater treatment is a natural treatment process that does not require the use of chemicals. Dairy wastewater is particularly suitable for biological wastewater treatment due to the high organic content. Also, the presence of nitrogen and phosphorous in many types of dairy wastewater also promote the use of biological dairy wastewater treatment.  

Natural bacteria used in the biological treatment process feed on and consume this organic material, thereby cleaning wastewater in a very natural way.

However, it is not that simple. There are a wide range of aerobic and anaerobic biological treatment technologies on the market. Due to the high variability of the flows and pollutant loadings in dairy wastewater, anaerobic treatment technologies that can be used to generate biogas are very difficult to manage. This is because the natural bacteria require very special conditions to work effectively.  

In addition, many aerobic process technologies used for biological treatment of dairy wastewater also struggle to deal with these variable flowrates and production changes.  

This is why we have developed, tested and implemented a special fixed film, cascaded biological wastewater treatment process specifically suited for industrial applications such as dairies. This FBBR process can handle a wide pH range, variations in flowrate and also big fluctuations in pollutant loadings. Our FBBR process has been tested at the leading independent wastewater test facility in Europe, and is proven to be highly effective for removing nitrogen, phosphorus, BOD, COD and ammonia from dairy wastewater. So if you are involved in dairy wastewater treatment plant design and you need biological treatment of dairy wastewater, FBBR is a guaranteed solution. 

Biological treatment of dairy wastewater can be used to achieve almost any cleaning standard required. We have completed projects for some of the best known dairies in Europe and have achieved the following cleaning standards: 

PIA FBBR approval document 

Speak to us about testing your wastewaster

Our main aim is to remove the risk for our customers. We make the design and procurement of a dairy wastewater treatment plant simple. 

With our in house laboratory that is staffed with expert chemists and biologists, we can run a complete range of tests on your wastewater and tell you exactly what process steps to use to meet your required cleaning standards.  

This is a totally no obligation service.  

We complete a range of custom tests developed for dairy customers, and then we issue a no obligation report clearly explaining what process technologies will work with your wastewater, and how effective each process step will be. 

This is a process that can be completed in less than one week and is available to clients anywhere in the world.  

For a no obligation discussion about testing, or to book your no obligation wastewater test, please fill out your details. We guarantee a response time of less than 1 working day.