Nutrient removal from farm effluents
N.S. Bolan a,*, L. Wong b, D.C. Adriano c
aSoil and Earth Science Group, Institute of Natural
Resources, Massey University, Palmerston North, New Zealand
bNew Zealand Bark Resource Ltd., Wellington, New Zealand C
Savannah River Ecology Laboratory, Drawer E, Aiken, SC 29802, USA
Received 18 March 2003; received in revised form 15 January 2004; accepted
15 January 2004
Available online 6 March 2004
Abstract
The objectives of the study were: (i) to examine the efficiency of nutrient
removal during the treatment of dairy farm effluent in a two-pond system,
and (ii) to produce an inexpensive but effective nutrient trap which could
be recycled as a nutrient source or soil mulch. The concentration of chemical
oxygen demand (COD), biological oxygen demand (BOD), nitrogen (N), phosphorus
(P) and potassium (K) in a two-pond system used to treat dairy farm effluent
was monitored over a period of 7 months. The retention of nutrients by
two porous materials was examined both in the laboratory batch (zeolite
and bark) and pilot-scale field (bark) experiments. The results indicated
that biological treatment of farm effluents using the two-pond system
was not effective in the removal of nutrients, which are likely to become
pollutant when discharged to waterways. Both the bark and zeolite materials
were effective in the removal ofN,P and K from effluent. These materials
can be placed in the second (i.e., aerobic) pond to treat effluents, which
can then be discharged to streams with minimum impact on water quality.
The nutrient-enriched porous materials can be recycled as a source of
nutrients and soil conditioner.
Keywords: Bark; BOD; COD; Farm efiluent; Nutrients; Suspended
solid; Pond treatment; Zeolite
SREL Reprint #2846
Bolan, N. S., L. Wong and D. C. Adriano. 2004. Nutrient removal from farm effluents. Bioresource Technology 94:251-260.
