London compost site clears the air

London - ACWA AIR, part of ACWA Services, has designed and installed an active carbon odour abatement system for the Compost Centre on LondonWaste’s Eco Park. The 30,000 tpa facility treats a wide range of biodegradable materials, including grass cuttings, kitchen scraps and foliage from parks, gardens and green spaces around north London.

The odour is caused by the movement of maturing compost, which generates gases including small quantities of NH3 of less than 30Mg/m3; CO2 from respiring bacteria, water vapour and steam and bioaerosols and dusts. The new system is installed within an enclosed maturing and compost storage building to extract odorous gases from the screening, separation and maturation processes. 

ACWA's process is designed to transform biodegradable waste matter into compost for use in agriculture, allotments, parks and gardens. The odour abatement system comprises high level ducting and a forced draught extraction fan which moves and directs odour to a vertical deep bed filter low profile arrangement that accepts an airflow of 45,0003/h.

According to the equipment maker, its bespoke filtration system adsorbes the odorous compounds and can cope with the seasonal variation of gases discharged from the treatment process. When the active carbon filter media is fully laden with waste compounds it is discharged from the system and can be recycled with the composting waste.