Watermark Projects and Cotteswold Dairy Limited have recently completed the first project for our Trial DAF Unit.
Where our usual trials would be an opportunity for our potential customers to test the effectiveness of the DAF system, Catteswold Dairy was in a unique position to provide an in-depth review of both the financial impact and the usability of the unit itself which was hugely beneficial for us to develop the system further.
Dairy Industries Magazine have featured the project in their August issue, based around waste water treatment. Below is the extended article which details the financial findings of Cotteswold Dairy Limited.
Dairy Industries Magazine Aug 2014:
Watermark Projects specialise in the design and manufacture of industrial wastewater treatment systems. One of the products in which we specialise is the Dissolved Air Flotation (DAF) process.
The DAF system is designed primarily for the efficient removal of suspended solids and COD from the majority of waste water streams.
The DAF process is both simple and effective; it uses a proportion of treated water which is uniquely saturated with air under pressure. When the air saturated water solution is released in the base of the DAF cell, there is an immediate pressure drop creating a mass formation of micro bubbles.
These bubbles attach themselves to solid particles flowing through the DAF cell and effectively float them to the surface of the cell. An automated scraper system then skims the surface of the water removing the floated solids leaving the clear water to flow out of the DAF unit.
Following feedback from a number of our clients regarding their interest in the DAF process, we decided to develop a trial unit which would allow our potential and current clients to see first hand how efficient and cost effective our DAF process is.
Using their experience in this field our design team subsequently put together a high quality, extremely versatile and easily transportable mobile unit incorporating pH control, chemical coagulation, flocculation and a Dissolved Air Flotation system.
This unit not only demonstrates how the DAF process works but also how effectively it would treat the wastewater at source on the customer’s site.
Having worked with us in the past, Cotteswold Dairy Limited showed particular interest in the project and invited us to test the system at their Tewkesbury site. This would allow them to see a small scale DAF process in operation and work out the potential cost savings available when comparing influent against final effluent quality.
About Cotteswold Dairy
Project manager: Luke Beckingham
Cotteswold Dairy Ltd is a milk and cream only processing facility based in Tewkesbury, Gloucestershire. It is a family owned business processing 78 million litres of milk per annum and in 2013, celebrated its 75th anniversary of trading. For the last 3 years the company has invested heavily in 2 of its staff (Chris Walden and myself), for the development of key dairy industry skills through a foundation degree in Dairy Technology at Reaseheath college, better known as project Eden. The degree covered many modules over the 3 years but in year 3 there was a big final project to undertake. The project was to be of a technical nature with cost saving benefits to the company a key aspect. After looking at various possible ideas I chose to look at our effluent treatment system. Due to working with Watermark Projects in the past I got in touch with them and started the ball rolling on using their new pilot scale DAF unit for my project.
A four week feasibility trial was set up where by the system was delivered to site and quickly set up to effectively treat a representative portion of the sites waste water discharge.
Once installed it was found that the unit could treat 3,600 Liters per hour. This is below our current volume of effluent streams but all results taken were multiplied up to give a realistic figure. DAF units are at their most efficient when pH is used correctly to coincide with the chemistry that is needed. It was found that due to the high pH of effluent coming out of the dairy (12-14), a sulphuric acid dosing system had to be installed. Optimum efficiency for the unit was with pH 5.6-5.9. Once a week the whole factory CIP’s on acid rather than caustic which caused problems with the unit, this is because acid has a lower pH and there was no means of increasing it. A recommendation for the future would be to include a caustic dose in order to increase the pH, not just an acid dose to decrease. My overall opinion of the system however, is that it coped extremely well with our high levels of solids in effluent and did a fantastic job of decreasing COD levels.
After the four week trial period Cotteswold Dairies produced a feasibility & efficiency report based on the trial project.
Over the 4 week trial, results showed a significant decrease in total suspended solids and chemical oxygen demand. COD levels showed a marked reduction of approximately 50%. Unfortunately total suspended solids reduction is not yet calculated as the local water authority have not yet issued their latest statement, though huge improvement is expected. From the results gathered it was found that cost savings amounted to £144 per day, £864 per week and £44,928 per annum. There is also the total suspended solids to add to this saving so I would expect the figure to rise up to the £60,000 per annum mark overall.
From the results and figures collated, there is potential for huge savings and with investment of a full scale DAF plant, payback would be between 3-4 years. My final thoughts are that this would be highly beneficial to my company through cost savings, reducing our carbon footprint and setting up effluent resources ready for future expansion in production volume. Watermark Projects were a pleasure to work with. Any problems were dealt with immediately and Alistair Fielding (Watermark Projects Project Engineer) was always only a phone call away to assist in these matters. Due to the success of this project an excellent relationship between companies has developed and when the time comes for Cotteswold Dairy to invest in a full scale DAF unit Watermark Projects will be at the top of my list to contact.
Watermark Projects would like to take the opportunity to thank everyone at Cotteswold Dairies for working with us on this most valuable project. It was a pleasure working alongside Luke, Chris and the engineering team at Tewkesbury. They took great interest in the chemical treatment and DAF processes, assisting in all aspects of the set up and commissioning of the unit. Working with the team allowed us to quickly ‘iron out the kinks.’
We have taken on board their valuable comments and now our system has been refined to include two way pH control, so all eventualities for future trials are covered.
It will be a pleasure to offer our services to Cotteswold as and when they decide to move forward with the full scale project.
Thanks to the success of this project we have now developed a fleet of trial DAF systems to offer our clients.
For further information on see the Trial Equipment section of our website.
Visit the Watermark Projects website for more information on WATERMARK PROJECTS TRIAL DAF UNIT: DAIRY INDUSTRIES MAGAZINE