Liquid Manure Odor Control Techniques
The odor potential of land applied manure is directly related to the
degree of odor generated by the manure storage system. All manure storages
are not equal in their odor potential. Anaerobic processes are excellent odor
control processes if allowed to proceed to completion. Anaerobic lagoons
(Figure 44-1) have substantially lower odor potential due to a lower volatile
organic compound (VOC) emission rate (a primary source of odor) as
compared to other storage facilities. Spray irrigation of effluent from a
purple lagoon or oversized anaerobic lagoon can be accomplished with less
odor than spray irrigation from an earthen basin, below barn pit, or
undersized lagoon, which each have very high odor potentials. Manure
storage systems that allow anaerobic processes to proceed to completion can
be coupled with pivot application of effluents with modest odor risk.
The odor potential of anaerobic lagoons is affected by time, temperature,
and other factors related to the biological processes. Thus, management of
the facility is a critical factor in defining odor emission from the storage or
potential odor emissions during land application. For example, spray
irrigation from an anaerobic lagoon in July will have much less odor than
spray irrigation from the same lagoon in March.
Some anaerobic lagoon design considerations for minimizing odors are
as follow