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SPECTROSCOPIC APPROACHES TO DEFINING THE INORGANIC AND ORGANIC CONSTITUENTS OF BIOSOLIDS
Citation:
Scheckel*, K G. AND J A. Ryan*. SPECTROSCOPIC APPROACHES TO DEFINING THE INORGANIC AND ORGANIC CONSTITUENTS OF BIOSOLIDS. Presented at Sustainable Land Application Conference, Lake Buena Vista, FL, January 04 - 08, 2004.
Impact/Purpose:
To inform the public.
Description:
The long-term debate over the fate of metals in biosolids and biosolids-amended soils has traditionally relied on intellectual theory and empirical data. The results of decades of research illustrate that metals in biosolids-amended soils are retained at a higher rate than soils without biosolids-amendments indicating that either an individual or combination of constituents within biosolids is responsible for the elevated sorption capacity of biosolids-amended soils. The deliberation centers on the argument of inorganic phases versus organic material with respect to the accountable biosolids component as the effective sorbent faction. For example, the affinity of metals for organic substances has been well documented in the literature; however, studies have shown that as the level of organic matter returns to background level in biosolids-amended soils, metal retention is still prominent. The extremely recalcitrant organic phases may be responsible for metal retention but this is yet to be definitively proven. Further, this dismisses Beckett et al.'s (1979) time bomb theory which details how metals in biosolids-amended soils would become labile in the environment as the organic substances decompose. Likewise, recent research has suggested the influence of iron and manganese (oxide) phases may play a vital role in the sorption of metals; however, the exact mechanism of metal uptake (e.g., adsorption or coprecipitation into oxides or a combination thereof) has eluded researchers but the research itself is substantiated. The objective of this presentation is to put forward several spectroscopic examples of how one can better examine and decipher the influence of inorganic an organic constituents of biosolids.