Division BAT 19

United Kingdom

If on-farm processing of manure is used, in order to reduce emissions of nitrogen, phosphorus, odour and microbial pathogens to air and water and facilitate manure storage and/or landspreading, BAT is to process the manure by applying one or a combination of the techniques given below.

	Technique^f1	Applicability
A description of the techniques is given in Section 4.7.
a	Mechanical separation of slurry. This includes e.g.: Screw press separator; Decanter-centrifuge separator; Coagulation-Flocculation; Separation by sieves; Filter pressing.	Only applicable when: a reduction of nitrogen and phosphorus content is needed due to limited available land for manure application; manure cannot be transported for landspreading at a reasonable cost. The use of polyacrylamide as a flocculant may not be applicable due to the risk of acrylamide formation.
b	Anaerobic digestion of manure in a biogas installation.	This technique may not be generally applicable due to the high implementation cost.
c	Use of an external tunnel for manure drying.	Only applicable to manure from plants for laying hens. Not applicable to existing plants without manure belts.
d	Aerobic digestion (aeration) of slurry.	Only applicable when pathogen and odour reduction is important prior to landspreading. In cold climates, it may be difficult to maintain the required level of aeration during winter.
e	Nitrification-denitrification of slurry.	Not applicable to new plants/farms. Only applicable to existing plants/farms when the removal of nitrogen is necessary due to limited available land for manure application.
f	Composting of solid manure.	Only applicable when: manure cannot be transported for landspreading at a reasonable cost; pathogen and odour reduction is important prior to landspreading; there is enough space in the farm for windrows to be established.

Annotations

Footnotes

f1: A description of the techniques is given in Section 4.7.