On-site sludge treatment technology is offering big food and drink manufacturing companies the opportunity to make major cost savings, improve environmental performance and achieve significant operational benefits – and all with a payback of less than two years.

Commenting on a recent project by technology specialists HUBER Technology, Elaine Coles, Managing Editor of Waterbriefing said:

“With the potential to make huge savings on expensive road tanker costs, reduce waste disposal, deliver significant improvements in environmental performance and as an added bonus, produce a biomass by-product which can be used to generate electricity, the technology looks set to be the focus of growing interest from the big food and drink companies.”

And with the ability to achieve all this within a payback time of under two years, more of the key players in the sector will no doubt be beating a path to HUBER’s door.”

Single ready meal site in London saves £120,000 per year

HUBER Technology recently completed a sludge dewatering project for a large ready meal manufacturer in London. The site prepares ready meals for most of the UK supermarkets, producing large amounts of sludge as a result of the on-site wastewater treatment plant. With installation of a Huber Q-Press, the site now saves an estimated £120,000 per year, as well as achieving a number of operational benefits.

Before approaching HUBER, the site had an existing Dissolved Air Flotation (DAF) unit and were paying for the sludge to be removed in road tankers. This was both expensive and a logistical problem because of the restricted access around site, which is via a single-track road. Any time a tanker was on site, no other vehicles could make deliveries of ingredients or collections of manufactured ready meals.

DAF sludge thickens over time when stored in an un-mixed tank and it is common practice to decant clear water to reduce tanker volumes. Knowing this, the site operator decanted clear liquid from the sludge tank into the return well, to feed back to the DAF. However, since the sludge on site stratifies into both dense and light layers, with clear water between, sludge was frequently (accidentally) fed back to the DAF unit. This overloaded the DAF and caused the treated water quality to deteriorate, increasing the site’s Mogden charge as a result.

The site manager identified the potential for savings and contacted HUBER to evaluate treatment options. As part of a large multinational, he had to be sure of the financial viability of the project before making an application for capital from head office. There were a number of aspects to consider, such as:

• Equipment capital cost
• Operating and maintenance costs of the new equipment
• Existing disposal cost of the sludge
• Reduced disposal cost of the dewatered cake

Month-long on-site trial to assess equipment performance and ease of use

HUBER were able to offer an on-site trial using a containerised HUBER Screw Press Q-Press® unit, which was operated by site over the course of a month. This allowed the site manager to confidently assess not only the performance of the machine but the ease of operation and minimal amount of time required from site operatives. Following the trial, the client was issued with a detailed report, so that they could evaluate capital and operating costs.

Solution – “the investment was an obvious decision for the customer”

HUBER provided the full equipment scope to site, including:

• Q-Press Q440.2 screw press - sludge dewatering unit
• Automated polymer batching plant to flocculate the DAF sludge
• All feed and polymer pumps
• Twin conveyors to elevate dewatered cake and automatically distribute between three Dolavs
• Pre-programmed control panel to automate operation of the plant

As a result of the installation, the client no longer has to remove sludge in expensive road tankers and have moved to a free alternative. The dewatered cake is transported to a local Anaerobic Digestion plant and used to generate electricity. As well as saving money, the change has allowed the site to further reduce its environmental impact.

James Tucker, HUBER’s Industrial Business Development Manager commented:

“Our sludge dewatering press was commissioned in October last year, so has seen quite a bit of run time. Over the first 5 months, our client estimated they had already saved over £50k. It's an interesting installation. As there was no access for a trailer, we also provided the conveyor system, which distributes cake between Dolavs automatically based on level. It’s not easy to divert investment away from production, but with payback easily achieved within the 2 year target, making the investment was an obvious decision for the customer.”

For more information contact James Tucker on 07720 086808

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Visit the HUBER Technology website www.huber.co.uk