TY - JOUR
T1 - Phosphorus distribution in untreated and composted solid fractions from slurry separation
AU - Jørgensen, Karin
AU - Magid, Jakob
AU - Luxhøi, Jesper
AU - Jensen, Lars Stoumann
PY - 2010/1
Y1 - 2010/1
N2 - The distribution of phosphorus (P) (water-soluble inorganic P [P i], acid-soluble Pi, and residual P) was determined in 40 samples of solids from solid-liquid separated slurry. Th ese were collected from separation plants using diff erent technologies, separating by simple mechanical means, by flocculation as pretreatment before mechanical separation or by anaerobic digestion followed by separation and centrifugation. Simple mechanical separation yielded a low solid TP content (8-9 g P kg-1 dry matter [DM]) compared with separation by fl occulation (26 g P kg -1 DM) or by anaerobic digestion-centrifugation (33.4 g P kg -1 DM). Acid-soluble Pi predominated in the high P-yielding solids, whereas organic-bound or residual P was a minor component in all slurry solids. Acid-soluble Pi and residual P were signifi cantly correlated with total phosphorus (TP) content (R2 = 0.855 and R2 = 0.584), but water-soluble Pi was uncorrelated (R2 = 0.077). Th e relative distribution of Pi to TP in the solids showed a high proportion of water-soluble Pi in solids from simple mechanical separation, whereas the absolute concentrations were highest in solids from separation by fl occulation and anaerobic digestion-centrifugation. Th ree solid fractions, representing the range of solids variability produced by the separation techniques, were composted for 30 d, and the P distribution was compared before and after composting. Total mass of P was conserved during composting, but watersoluble Pi as a proportion of TP decreased in most cases. Th e most pronounced decrease in water-soluble Pi was observed during composting of the solids separated using flocculation. However, changes in short- to medium-term bioavailability of P were modest, and thus the potential benefi ts of composting regarding storage and handling can presumably be realized without seriously compromising the P fertilization quality.
AB - The distribution of phosphorus (P) (water-soluble inorganic P [P i], acid-soluble Pi, and residual P) was determined in 40 samples of solids from solid-liquid separated slurry. Th ese were collected from separation plants using diff erent technologies, separating by simple mechanical means, by flocculation as pretreatment before mechanical separation or by anaerobic digestion followed by separation and centrifugation. Simple mechanical separation yielded a low solid TP content (8-9 g P kg-1 dry matter [DM]) compared with separation by fl occulation (26 g P kg -1 DM) or by anaerobic digestion-centrifugation (33.4 g P kg -1 DM). Acid-soluble Pi predominated in the high P-yielding solids, whereas organic-bound or residual P was a minor component in all slurry solids. Acid-soluble Pi and residual P were signifi cantly correlated with total phosphorus (TP) content (R2 = 0.855 and R2 = 0.584), but water-soluble Pi was uncorrelated (R2 = 0.077). Th e relative distribution of Pi to TP in the solids showed a high proportion of water-soluble Pi in solids from simple mechanical separation, whereas the absolute concentrations were highest in solids from separation by fl occulation and anaerobic digestion-centrifugation. Th ree solid fractions, representing the range of solids variability produced by the separation techniques, were composted for 30 d, and the P distribution was compared before and after composting. Total mass of P was conserved during composting, but watersoluble Pi as a proportion of TP decreased in most cases. Th e most pronounced decrease in water-soluble Pi was observed during composting of the solids separated using flocculation. However, changes in short- to medium-term bioavailability of P were modest, and thus the potential benefi ts of composting regarding storage and handling can presumably be realized without seriously compromising the P fertilization quality.
U2 - 10.2134/jeq2009.0168
DO - 10.2134/jeq2009.0168
M3 - Journal article
C2 - 20048327
SN - 0047-2425
VL - 39
SP - 393
EP - 401
JO - Journal of Environmental Quality
JF - Journal of Environmental Quality
IS - 1
ER -