NUTRIENT LEACHING FROM CARBON PRODUCTS OF SLUDGE

NUTRIENT LEACHING FROM CARBON PRODUCTS OF SLUDGE
Yoshiyuki Shinogi, National Institute for Rural Engineering, Japan, 2004
ASABE/CSAE Paper 0440063

ABSTRACT
We proposed pyrolysis as a promising optional technology for recycling waste products,
especially sewage sludge and animal waste (manure). In this study, nutrient (nitrogen,
phosphorous and potassium) leaching characteristics of carbon products mainly from sewage sludge and cattle waste were analyzed. Results are summarized as follows: 1) Electrical conductivity (EC) of carbon product solutes increase with time, and phosphate and sulfuric ions dissolve gradually from the carbon products of both sewage sludge and cattle waste; 2) Nitrogen decreases with manufacturing temperature and nutrient concentration of phosphorous and potassium are larger; Both phosphorous and potassium are citric soluble and easily available for crop production; and 3) The ratio of nitrogen to phosphorous and potassium can be controlled through the manufacturing temperature. These results provide valuable information for utilizing
carbon products from waste products.

KEYWORDS: pyrolysis, carbon products, nutrient

CONCLUSION
The characteristics of carbon product nutrients, mainly from waste and sludge, were analyzed and
the following valuable results were obtained:
1) Electrical conductivity (EC) of carbon product solutes increase with time. Phosphate and sulfuric ions dissolve gradually from the carbon products of both sewage sludge and cattle waste.
2) Nitrogen decreases with manufacturing temperature and nutrient concentrations of phosphorous and potassium are large. Both phosphorous and potassium are citric soluble and easily available for crop production.
3) The ratios of nitrogen, phosphorous and potassium can be controlled through the manufacturing temperature.

Further research is required, particularly on the leaching mechanisms of nutrients.

Written for presentation at the 2004 ASAE/CSAE Annual International Meeting Sponsored by ASAE/CSAE Fairmont Chateau Laurier, The Westin, Government Centre Ottawa, Ontario, Canada 1 - 4 August 2004