1 research outputs found
Characterization, Recovery Opportunities, and Valuation of Metals in Municipal Sludges from U.S. Wastewater Treatment Plants Nationwide
U.S. sewage sludges were analyzed for 58 regulated and nonregulated
elements by ICP-MS and electron microscopy to explore opportunities
for removal and recovery. Sludge/water distribution coefficients (<i>K</i><sub>D</sub>, L/kg dry weight) spanned 5 orders of magnitude,
indicating significant metal accumulation in biosolids. Rare-earth
elements and minor metals (Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy,
Ho, Er, Tm, Yb, Lu) detected in sludges showed enrichment factors
(EFs) near unity, suggesting dust or soils as likely dominant sources.
In contrast, most platinum group elements (i.e., Ru, Rh, Pd, Pt) showed
high EF and <i>K</i><sub>D</sub> values, indicating anthropogenic
sources. Numerous metallic and metal oxide colloids (<100–500
nm diameter) were detected; the morphology of abundant aggregates
of primary particles measuring <100 nm provided clues to their
origin. For a community of 1 million people, metals in biosolids were
valued at up to USValue) to capture
the <i>relative potential for economic value from biosolids</i> revealed the identity of the 13 most lucrative elements (Ag, Cu,
Au, P, Fe, Pd, Mn, Zn, Ir, Al, Cd, Ti, Ga, and Cr) with a combined
value of US $280/ton of sludge