Ecolo Odor Control Systems Worldwide

airSolution perimeter systems to deal with odors at the final effluent treatment stage, one around a lagoon and one around an emergency basin, having a combined capacity of 4 million gallons. The components of each system include a hydraulic pump, an airSolution reservoir, a timer to turn the system on and off automatically, a series of atomizing nozzles strung on 8ft. posts at 20 ft. intervals, and a length of ¼ in. nylon hose. The two systems have more than 100 atomizing nozzles, took a week to install, and operate during the “outdoor odor season” from May to November.

Denis Berthiaume, the manager responsible for effluent treatment, initiated the acquisition of the systems in response to odor complaints from residents in the two affected municipalities, with support from their respective councils, the provincial government and mill employees. Previously, M. Berthiaume had experimented unsuccessfully with masking agents, oxidants and aeration. Following installation of the systems, complaints declined by 80%.

In accordance with standard industry practice. M. Berthiaume also continues to search for modifications “at source” that will reduce odors further. How does the system control odors?

Fine droplets (<20 microns) atomized at each nozzles are carried by air currents, react on contract with molecules of gaseous hydrogen sulphide (H2S) rising from the lagoons. The Lewis base incorporated in this formulation has a pair of electrons available for forming a bond with an electron-pair acceptor. A proton or hydrogen ion (H+) of hydrogen sulphide appears to be such an acceptor. In less than two seconds a compound containing non-odorous hydrosulphide ions (HS-) is formed which, in the presence of atmospheric oxygen (O2), is oxidized into sulphate ions (SO4-).

These sulphate ions eventually biograde to elemental sulphur and oxygen. Some droplets settle on the surface of the lagoons where they intercept and neutralize odorous gases as they rise to the surface. The droplets contain a precise and proprietary blend of several hundred essential oils, which being aromatic, present a pleasing scent on initial release.

Odor Impacts- An overview, the Science and Technology Branch of the Ontario Ministry of Environment and Energy includes “pulp and paper plants” in its list of “operations that commonly result in odor impacts.” Sources of odorous emissions include the black liquor recovery process, from brown stock washers, and from effluent treatment systems, digesters and lime kilns.
In 1996 the Rolland Paper Mill in St. Jerome, Quebec, installed two Ecolo