Biffa makes aggregate quality improvements at recycling plant

Biffa Waste Services is diverting 99% of road sweepings material from landfill at its new West Sussex Treatment Facility, aided by a new road sweepings recycling system, as explained in this case study from recycling equipment specialist CDEnviro.

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Clean sand and aggregates at Biffa’s treatment facility.

Biffa controls the largest volume of waste in the UK, placing the company at the centre of a dynamic and growing sector, providing indispensable services to all UK businesses. Recently the firm invested in a CDEnviro road sweepings recycling system. The decision was based on a detailed ROI analysis which included bringing in waste streams for processing from regional municipal clients. The new system, installed and commissioned in October 2015, is helping Biffa to achieve sustainability and promote the highest standard of environmental compliance in its activities.

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Biffa road sweepings recycling plant.

The solution
The recycling solution is based in Horsham at one of the company’s 14 operational landfill sites. It consists of a range of products from CDEnviro including a HYDRO:GRADE system which screens and scrubs material to ensure effective removal of contaminants, a sand washing plant and a HYDRO:FLO water treatment system. A trommel at the start of the process protects the system and removes oversize contaminants from the feed system. A centrifuge is also used to maximise recycled water within the CDEnviro system.
The solution includes a new advanced liquid/solid separation module, CO:FLO, developed by CDEnviro in 2015. CO:FLO is a multi-stage chemical dosing system which ensures water quality that is unparalleled in the solid waste recycling industry.

Glass recycling
The solution was purchased in order to process 50,000 TPA of street cleansing residues from the surrounding areas. However, the processing solution is now accepting multiple waste streams including residual material from locally based material recycling facilities (MRFs). In recent years Biffa has invested around £35 million in MRFs to improve segregation, processing and decontamination of single stream and mixed recyclable materials. The glass fraction now processed in the system was initially trialled on a traditional system, however the results from the CDEnviro unit are far superior both in terms of quality and quantity of glass recovered.

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Glass recycling

Mark Harley, National Development Manager at Biffa commented: “We trialled numerous residual materials from MRFs through the CDEnviro system and the results are extraordinary in comparison to our previous traditional approach. A fantastic aggregate product is generated ready to supply to the market giving our clients a true circular economy solution.” The system produces three final products ready for re-use; two aggregate products and one sand product. The aggregate product is used on the site for land drainage. Biffa is working to achieve end of waste status for the recovered sand product, resulting in unlimited possibilities for re-use. A further two products, dewatered centrifuge cake and washed organics are further treated in house at Biffa’s Redhill Soil Treatment facility. This is a hazardous soil treatment process to remove hydrocarbons within the by- products and then utilised as land restoration material.

Road sweepings recycling
The Road Sweepings Recycling system at West Sussex is the first time Biffa has invested in a wet processing solution. Harley said: “CDEnviro brought a new, innovative approach to our processing of waste. The new solution effectively screens, classifies and dewaters our waste streams allowing us to divert 99% of road sweepings material from landfill. The effective recovery and re-use of materials from this solution ensures we are providing the most creative and sustainable waste management service in the UK.”
Road sweepings and gully waste have proven to be a valuable resource with many materials being recovered for re use.