Central to the system will be Advetec’s first industrial scale, Bio-Thermic Digester that will reduce organic waste from fat traps, septic tanks, filter cakes and municipal collections by 96 percent.
RWR, which collects the majority of the liquid waste within the M25 area, treats more than 300,000 liters of roadside, septic tank, flood and industrially contaminated water and 150 metric tons of municipal waste daily. After trials of a smaller Bio-Thermic Digester, Advetec has supplied and installed a new, industrial scale machine, which will process up to 33 metric tons of organic waste within 72 hours.
John Edwards, director of RWR says the smaller machines turned more than 90 percent of organic waste into clean water and dry power, so RWR expects the larger machine to “cope with the huge volumes of solid sludge/organic waste we receive every day.”
From RWR’s Materials Recycling facility black bag waste is shredded, crushed and segregated with the majority of heavy pieces of glass, sand, metal and plastics removed. The waste is then delivered in tankers to Stratford where the tromelled waste is washed to remove more sand, glass, metal and then entered into a centrifuge to separate the waste into solid and liquid. The organic waste then will go via hoppers and augers into the new Bio-Thermic Digester.
Heat from beneath the new container-sized BTD will maintain a controlled temperature and this, together with a regulated air supply and doses of proprietary bio-nutrients, will remove moisture and promote oxygenation to reduce hard carbon particulates. Finally residual metal, glass and plastics are removed, while the remaining organics are reduced to a fine, sterile powder.
Instead of typical landfill costs of £80/90 ($137/$154) per metric ton, RWR’s costs will be around £1.99 ($3.42) per metric ton to process on site, offering a typical return on investment within 18 months.
In other zero-waste news, last week Eaton said 39 of its manufacturing facilities around the globe have achieved zero waste, according to the power management company, which in 2013 reduced its landfilled wastes by about 18 percent, or 4,900 metric tons, as part of a global zero waste-to-landfill program.