Tipperary Creamery receives major improvement to odour management using Warden Biomedia’s high surface area, high efficiency filter media.
Tipperary Cooperative Creamery in Ireland processes around a million litres of milk daily, producing around 60,000 tonnes of cheeses, butters, milk powders and other dairy products every year to be sold in Ireland and across Europe, UK, USA, Middle East and Asia.
As one of the largest employers in the area, Tipperary Co-op takes the company’s responsibilities to the environment and local community seriously. In order to assess the performance of odour abatement technology on site and to ensure continued compliance, Tipperary engaged MEHS, specialists in environment, health and safety to ensure that the system was fully fit for purpose.
Examination of the Existing Odour Control System
The Tipperary Co-op’s existing odour control system was designed to treat 7500 Nm³/h of air. Two centrifugal fans operating as duty and standby extract air from the production areas and blow it upwards through an odour control unit to be discharged via a stack into the air. The odour control unit consists of a tank containing 33 m³ of mussel shells media supported on a layer of clam and oyster shells.
Water is continuously circulated from the bottom of the tower to spray distributors at the top which give even distribution over the media. Bacteria in the circulating water biologically remove the odour-producing contaminants.
When MEHS checked the odour control system, they found the air flow was only 600 Nm³/hr, a significant order of magnitude below the design figure. After opening the unit, it was found the system performance was affected by the mussel shell media breakages, which had reduced voidage to such an extent that water hold-up, or ponding, was occurring which was impeding the flow of air through the media and reducing the efficiency of the process.
Addition of the New Media
MEHS removed the old media, power washed the scrubber and installed two types of new media, 1.8 m depth of Bioflo+ supported on a layer of Bioball 0.3 m, both designed and manufactured by Warden Biomedia. MEHS also installed an automated pH control system to control the pH between 8.5 and 9.5.
Project Success
After adding the new media, the water recycle was re-started and concentrated bacteria added to system. The air flow was checked at 7,500 Nm³/hr and the inlet and outlet flow sampled for odorous parameters by SOCOTEC UK, an accredited laboratory.
The odour concentration on the inlet was 25,747 OUE/m³ and the outlet odour concentration was 350 OUE/m³ – a 98.6% reduction of the odour concentration.
Table 1 – Inlet & Outlet Concentrations
The media have a high surface area, which is important for contact between the liquid and gas, but also means a low pressure drop, minimising fan power. Whilst the cost of the new media was similar to the replacement of the shell media, the plastic media are durable with high resistance, therefore unlike the shells, the media will not be replaced.
Bioball filter media
Bioball is made from recycled polypropylene with internal fins and large openings, offering a surface area of 220m²/m³ and voidage of 92%. The structure and surface textures of the biomedia provide a protected environment to host the beneficial bacteria needed for biological treatment processes.
Bioflo+ filter media
Bioflo+ has a wheel shape with internal fins and large openings, offering a huge protected surface area of 800m²/m³ and voidage of 63%. Bioflo+ is designed to provide a large protected surface area for the biofilm and optimal conditions for the bacteria culture when the media are suspended in water.
Bioflo+ is ideal for odour scrubbing applications; the high surface area gives optimum air to wet surface contact time to help eliminate odour issues and the high voidage means a low pressure drop on the gas side, minimising fan power helping contribute to environmental and sustainability targets.
Contact details
Declan Haylock
Business Development Manager
Warden Biomedia
Email: Declan.Haylock@wardenbiomedia.com
Tel: 01582 573 030
