Recycling and reuse of waste streams in the dairy processing industry
ESAS Project 10.10
Background | Less water, less salt at two dairy processors | Notable achievements at Burra Foods | Notable achievements at Warrnambool Cheese and Butter | Research Projects| Biomarker research | Reed bed research | Further information
This project aims to assist Victorian dairy companies to use less water and to produce less trade waste during their processing operations.
The project was established under Action 10.10 of the Environmental Sustainability Action Statement (ESAS) (external link) and is supported by the Victorian Government Sustainability Fund.
Background
Dairy food processing plants traditionally use large volumes of water when processing milk and cheese. In times of drought this puts a lot of pressure on the urban water systems that supply those plants. Current processes can also generate large volumes of salty wastewater. These salt loads are difficult to treat in conventional urban wastewater treatment plants.
To facilitate water savings and trade waste reduction in the dairy processing industry, the Victorian Government Sustainability Fund has invested $4 million in this project over the period 2006-2010.
Less water, less salt at two dairy processors
ESAS project 10.10 has established pilot water reduction and waste recycling programs at two regional dairy processors. The technology and process improvements developed at these pilot sites will be disseminated to other dairy processors throughout Victoria, enabling them to develop more sustainable production systems.
- The pilot dairy processors involved are:
- Burra Foods Pty Ltd at Korumburra in South Gippsland
- Warrnambool Cheese and Butter Company Holdings Ltd at Allansford in south-west Victoria.
Sample cartridges being extracted - DPI
Warrnambool Cheese and Butter (WCB) is Australia’s fourth largest milk processor, with revenue of approximately $510 million in 2007/08. It employs about 300 permanent and up to 100 casual staff in the Warrnambool region during peak production. It exports approximately 40% of its cheeses and the majority of its milk powder and whey protein concentrate to Japan, China, South East Asia, Europe and the USA. The company has established a dedicated R&D division to enhance its export product range, and to assist in waste management and input cost control.
The different scale of each operation will provide a wide range of learnings to dairy processors in Victoria.
Both companies were selected for the pilot study because of their commitment to waste prevention, minimisation and water use efficiency. WCB was also involved in the project ‘Closing the Loop: An holistic approach to the management of dairy processor waste streams (2003-06)’.
Notable achievements at Burra Foods
- Burra Foods (BF) no longer discharges wastes into Venus Bay. Process improvements mean that wastes are now treated to a level where they can be disposed of as trade waste to the sewerage system.
- BF has implemented a range of processing efficiency and recycling measures which saved approximately 150 million litres (ML) of water from the town supply in 2008. The long term goal of this system is to become water neutral.
- Energy savings have also been achieved through avoided water heating.
- The factory has provided over 10 ML of treated water for watering of local community recreational grounds during 08/09. A proposal to recycle treated sludge back to local farms is currently waiting EPA approval.
- Burra Foods have disseminated the learnings from this project to the wider dairy processing industry via a presentation by Dr Karl Wild to the Australian Institute of Food Science Technology (AIFST) Convention in July 09. A number of other dairy and food processors have already been to the Burra Foods site to observe and learn from the work.
Fosters Creek
Notable achievements at Warrnambool Cheese and Butter
- Warrnambool Cheese and Butter (WCB) completed a substantial investigation on the use of electro-dialysis bipolar membrane (EDBM) technology for salt removal from the waste streams in its cheese making plant. This technology has not been used routinely in the dairy processing industry before, so the concept was quite innovative. The investigation found that:
- EDBM technology is not financially viable for WCB at this stage, principally due to the high electricity operating costs.
- Under current electricity supply arrangements, the technology would also produce high levels of carbon dioxide equivalent (CO2e). If substantial levels of relatively cheap renewable energy could be accessed nearby, this assessment could be reversed.
A paper on the learnings from this work is currently under preparation, and is expected to be published in the Australian Journal of Dairy Technology.
- WCB has subsequently completed the planning and design for an alternative salt removal and water reduction strategy which focuses on chemical recovery from its Cleaning in Place (CIP) waste streams. Cleaning chemicals are conventionally used once and then dumped to the sewer, so the systematic collection and treatment of CIP waste streams at a multi-process, site-wide level is not routinely practised by dairy processors in Victoria. This initiative has been assessed as financially viable for WCB. Construction has commenced, and the new plant is expected to be operational by February 2010.
- When operational the CIP Chemical Recovery project is expected to:
- save an estimated 50 ML of water per year from the domestic water supply system
- reduce the salt load in its trade waste stream by approx 500 tonnes per year
- reduce greenhouse gas emissions by 428 t CO2e (chemical full life cycle).
- The learnings from this work are expected to be disseminated to the wider dairy processing industry via a paper to conferences such as the Australian Water Association or the AIFST conference.
CIP nan-filtration plant at WCB
DPI has also established two complementary R&D projects, one at Ellinbank which is working with BF to optimise opportunities for wastewater recycling, and the second at WCB to explore the effectiveness of removing nutrients and organic material from saline dairy wastewater using reed bed technology.
Biomarker research
Organic contaminants in dairy processing wastewaters may limit options for re-use both within the factory and in the wider environment. DPI Future Farming Systems Research (FFSR) Division, in collaboration with Monash University, has established equipment and laboratory procedures which are being used to examine organic species, particularly those that exhibit environmental persistence and/or toxicity, in Burra Foods wastewaters. This research has assisted Burra Foods in developing new re-use opportunities. For example, data from the project has been used to support approval to use erstwhile wastewaters to supplement flows in nearby Foster creek, after the Burra Foods plant is upgraded in 2010.
Reed bed research
The common reed, Phragmites australis, is commonly used in constructed wetlands used for pollution control. The giant reed, Arundo donax, has been less often used, despite it producing considerably more biomass than P. australis. If A. donax can be shown to survive in, and perform as well as, P. australis in constructed wetlands designed to remove organics and nutrients from highly saline dairy processing waste water, the large quantities of biomass generated may provide a useful source of bio-energy for the dairy processing plant or other users. The aims of this work are therefore to demonstrate:
- the ‘proof of concept’ that A. donax performs as well as P. australis in constructed wetlands designed to remove biochemical oxygen demand from highly saline dairy waste water
- the formula for the % removal of organic wastes classically used in the design of horizontal subsurface flow wetlands is applicable to this situation.
Highlights of the DPI reed bed research are:
- The research group at Queenscliff has established trial plots of A. donax and P. australis at WCB’s Allansford site. This is enabling field testing of the reeds at salinity levels which are commonly found in dairy wastewaters (i.e. an EC of ~ 2500 mS). Testing is expected to continue until April 2010.
- A parallel series of laboratory experiments has also been established. This will enable the viability of A. donax to be tested at other salinity levels.
Further information
Information on developments at each factory and DPI research site is available from:
- DPI
- Dairy Manufacturers Sustainability Council (external link)
- Warrnambool Cheese and Butter (external link)
- Burra Foods (external link)
© The State of Victoria, 1996 - 2012.
This document was last reviewed on 27/10/2011