Reducing waste is a key goal for any business, whether it’s simply using less stationery or optimising steel manufacturing, but it is often far more literal in the dairy industry. In general, creating a kilogram of dairy produce requires somewhere between two and four litres of water, but it can generate anything from just half a litre of wastewater up to over 20 litres. To some extent, this will depend on the dairy product being made, but there are still huge variations in wastewater generation between dairies, even when making the same product.
Another waste material for dairies is acid whey, a by-product generated in the production of fresh cheeses and certain yoghurts such as Greek yoghurt. Considered to have no commercial value, acid whey is often disposed of through the agricultural sector, either by mixing it into cattle feed or spreading it onto land as a fertiliser. However, using large quantities of acid whey or other high COD liquid wastes in this way carries the risk of run-off into nearby waterways. This can lead to algal blooms which endanger the local aquaculture, and so understandably there is increasing regulatory pressure to limit the use of these high COD waste streams on farmland. As a result, many dairies are now looking at alternative solutions for the disposal of these waste by-products.
Unfortunately, this is being complicated by the fact that population growth is increasing the demand for dairy produce, leading to many dairies expanding their operations. This is putting increasing pressure on existing waste treatment facilities; many dairies are now at the edge of capacity for wastewater treatment, and must invest in new equipment to support continued growth. This combination of factors, not to mention the rising cost of wastewater discharge and growing consumer pressure on businesses to reduce their environmental impact, has created an opportunity for businesses to embrace new technologies that can reduce waste and costs, and even create new revenue streams.
There are a wide range of processing technologies which may be applicable for these high COD wastewater streams, from dissolved air flotation (DAF) to anaerobic membrane bioreactors (AnMBRs), depending on the exact requirements of the individual dairy. The composition of the waste stream will vary significantly between milk and ice-cream production, for example, and a multistep process is generally required to concentrate the wastewater, extract nutrient, biogas and other high value components, then make the effluent safe for discharge to the sewers or local water courses. Working with an experienced and trusted technology can help businesses to make the most of these technical innovations, reducing disposal costs and creating value-added products such as biogas, which can be used for on-site heating and electricity generation to further reduce costs, or sold back to the grid to provide an additional source of revenue.
At Veolia Water Technologies, we’re ideally positioned to help dairies wishing to reduce their wastewater costs or upgrade existing processing facilities, combining many years of experience in the sector with a broad spectrum of advanced solutions to suit virtually any business. Our latest offering, the state-of-the-art Memthane®, is an AnMBR system capable of transforming high strength wastewaters (8,000-75,000 mg/l COD) into crystal clear effluents that can be reused or discharged directly to sewer. This compact, easy to operate solution is ideally suited to the dairy industry, offering combined treatment of wastewater and organic waste to reduce disposal costs, while simultaneously generating valuable biogas. Veolia’s technology-led approach can help dairies to transform the way they handle waste, working towards a greener, more efficient and more sustainable future.
To find out more about generating value from dairy processing effluent, watch our on-demand webinar click here