A cleaner sweep

Biffa Waste Services has installed an innovative 50,000 tonnes-per-year plant to process street sweepings at its treatment facility in Horsham, West Sussex. Designed and installed by CDEnviro, the machinery has also begun accepting residual material from material recycling facilities (MRFs) to improve the segregation of aggregates.

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. Based at one of the company’s 14 operational landfill sites, the process consists of 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.

Process

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 also includes a new advanced liquid/solid separation module, CO:FLO – a multi-stage chemical dosing system developed by CDEnviro in 2015.

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. 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 from the by-products and then utilised as land restoration material.

Results

Commenting on the new system, Mark Harley, national development manager at Biffa, said: “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 Road Sweepings Recycling system at West Sussex is the first time Biffa has invested in a wet processing solution. Mr Harley added: “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.”