PROBABLE PHOSPHORUS SOLID PHASES AND THEIR STABILITY IN ANAEROBICALLY DIGESTED DAIRY MANURE

Solid phases determining phosphorus (P) extractability from anaerobically digested dairy manure have not been investigated in detail. The objective of this study was to elucidate the dominant inorganic P phases controlling P solubility and to evaluate their stability after anaerobic digestion using geochemical equilibrium modeling with Mineql+ software. A companion article focuses on changes in water extractability of P after anaerobic digestion. Mineql+ simulations were performed using chemical composition data obtained by subjecting both untreated and anaerobically digested manure to two independent deionized water extraction methods, namely, serial and repeated extractions. The serial and repeated water extractions were intended to mimic the effect of single and consecutive storm events, respectively. Serial extractions consisted of single-step extractions with extractant to manure ratios (EMRs) ranging from 3 to 127 (wet mass basis), and repeated (six-step) extraction had an initial EMR of 3. Mineql+ simulations of the water extracts showed that struvite, beta-tricalcium phosphate (beta-TCP), and octacalcium phosphate (OCP) were the probable phases controlling P solubility. Anaerobic digestion did not significantly change P release trends and the type of predominant inorganic P solid phases. Overall, there was a good agreement in the Mineql+ simulation results for manure extracts obtained from the two independent water extraction methods. Phosphorus solubility appears to be initially (low runoff volumes and the first few runoff events after land application) controlled by more soluble P solid phases, mainly struvite (MgNH4PO4·6H2O), after which (for larger and later runoff events) sparingly soluble phases, such as OCP/beta-TCP-like phases, exert their influence on P release from anaerobically treated dairy manure.

[1]  Peter J. A. Kleinman,et al.  Measuring Water-Extractable Phosphorus in Manure as an Indicator of Phosphorus in Runoff , 2002 .

[2]  H. Kirchmann,et al.  Relationship between N immobilization and volatile fatty acids in soil after application of pig and cattle slurry , 1993, Biology and Fertility of Soils.

[3]  Kenneth M. Portier,et al.  Forms of phosphorus in soil profiles from dairies of South Florida , 1995 .

[4]  A. Sharpley,et al.  Phosphorus forms in manure and compost and their release during simulated rainfall , 2000 .

[5]  A Keshtkar,et al.  Dynamic simulation of cyclic batch anaerobic digestion of cattle manure. , 2001, Bioresource technology.

[6]  P. Leinweber,et al.  Sequential extractions and 31P-NMR spectroscopy of phosphorus forms in animal manures, whole soils and particle-size separates from a densely populated livestock area in northwest Germany , 1997, Biology and Fertility of Soils.

[7]  A. Sharpley,et al.  Amounts, Forms, and Solubility of Phosphorus in Soils Receiving Manure , 2004 .

[8]  Dwayne R. Edwards,et al.  Minimizing surface water eutrophication from agriculture by phosphorus management , 1994 .

[9]  C. Forster,et al.  Batch co-digestion of multi-component agro-wastes. , 2001, Bioresource technology.

[10]  E. Eanes,et al.  A thermodynamic analysis of the amorphous to crystalline calcium phosphate transformation , 1978, Calcified Tissue Research.

[11]  K. Isermann,et al.  Share of agriculture in nitrogen and phosphorus emissions into the surface waters of Western Europe against the background of their eutrophication , 1990, Fertilizer research.

[12]  U. Schwertmann,et al.  Composition and Reactions of Liquid Manure (Gülle), with Particular Reference to Phosphate: II. Solid Phase Components , 1977 .

[13]  E. Witter,et al.  Composition of fresh, aerobic and anaerobic farm animal dungs , 1992 .

[14]  G. Barnett.  Phosphorus forms in animal manure , 1994 .

[15]  Edward D. Schroeder,et al.  Predicting struvite formation in digestion , 1998 .

[16]  W. Inskeep,et al.  Precipitation of Dicalcium Phosphate Dihydrate in the Presence of Organic Acids , 1991 .

[17]  N. Patni,et al.  Volatile Fatty Acids in Stored Dairy-Cattle Slurry* , 1985 .

[18]  V. Nair,et al.  Associated release of magnesium and phosphorus from active and abandoned dairy soils. , 2005, Journal of environmental quality.

[19]  D. Sparks,et al.  Solid-state speciation of natural and alum-amended poultry litter using XANES spectroscopy. , 2002, Environmental science & technology.

[20]  G. Barnett.  Manure P fractionation , 1994 .

[21]  Perry L. McCarty,et al.  Effects of carbonate and magnesium on calcium phosphate precipitation , 1971 .

[22]  Z. Dou,et al.  Laboratory Procedures for Characterizing Manure Phosphorus , 2000 .

[23]  S. Sung,et al.  Performance of temperature-phased anaerobic digestion (TPAD) system treating dairy cattle wastes. , 2003, Water research.

[24]  J. Bril,et al.  Chemical composition of animal manure: a modelling approach. , 1990 .

[25]  J. Stewart,et al.  Changes in Inorganic and Organic Soil Phosphorus Fractions Induced by Cultivation Practices and by Laboratory Incubations1 , 1982 .

[26]  K. Harmsen,et al.  Determination of mass balances and ionic balances in animal manure , 1990 .

[27]  T. C. Daniel,et al.  Impacts of animal manure management on ground and surface water quality. , 1998 .

[28]  Andrew N. Sharpley,et al.  Phosphorus management at the watershed scale:a modification of the phosphorus index , 2000 .

[29]  G. K. Anderson,et al.  Determination of bicarbonate and total volatile acid concentration in anaerobic digesters using a simple titration , 1992 .

[30]  K. Reddy,et al.  Stability of phosphorus forms in dairy-impacted soils under simulated leaching☆ , 1995 .

[31]  Victoria E. Santos,et al.  Kinetic model for anaerobic digestion of livestock manure , 1999 .

[32]  E. Beauchamp,et al.  EFFECT OF CARBON CONSTITUENTS IN MANURE ON DENITRIFICATION IN SOIL , 1989 .

[33]  E. Temminghoff,et al.  Effects of different treatments of cattle slurry manure on water-extractable phosphorus , 2003 .

[34]  P. N. Hobson,et al.  A model of anaerobic bacterial degradation of solid substrates in a batch digester , 1985 .

[35]  K. G. Karthikeyan,et al.  Influence of anaerobic digestion on dairy manure phosphorus extractability. , 2005 .

[36]  Benjamin L Turner.  Optimizing phosphorus characterization in animal manures by solution phosphorus-31 nuclear magnetic resonance spectroscopy. , 2004, Journal of environmental quality.