Proton and metal complexation by water-soluble ligands extracted from anaerobically digested sewage sludge

Journal Article · · J. Environ. Qual.; (United States)

OSTI ID:7033708

Baham, J; Sposito, G

A water-soluble extract (WSE) of an anaerobically-digested sewage sludge containing 19.5 mol m/sup -3/ (19.5 mM) total soluble carbon (C/sub TS/) was acidified to pH 3 and titrated with NaOH to pH 11 in a 50 mol m/sup 3/ (50 mM) NaClO/sub 4/, background at 25/sup 0/C. Conditional protonation constants were determined from the formation function computed from the titration data. The common logarithms of the average protonation constants for functional groups titrated between pH 3 and 11 were 4.2, 7.2, and 9.6. Trace metal-WSE complexes were chromatographed on a molecular size exclusion gel. Copper formed the more stable complexes with the ligands in the WSE when compared to Ni or Cd. Cadmium was present predominately as the free metal ion or in inorganic complexes. Adsorption of Cu by montmorillonite was significantly reduced in the presence of the WSE. Since most of the organic carbon present in the WSE remained in solution during the adsorption experiments, the primary factor controlling Cu solubility was concluded to be the formation of soluble organo-Cu complexes. A mixture model was developed to simulate qualitatively the proton binding of the inorganic and organic components of the WSE. This model included organic and inorganic ligands whose relative concentrations were previously analytically determined for the WSE. The mixture model ligands were employed to model Cu and Cd speciation for gel filtration and adsorption experiments. The mixture model qualitatively explained the observed speciation in both experiments.

• Research Organization: Oregon State Univ., Corvallis
• OSTI ID: 7033708
• Journal Information: J. Environ. Qual.; (United States), Journal Name: J. Environ. Qual.; (United States) Vol. 15:3; ISSN JEVQA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400102* -- Chemical & Spectral Procedures
510200 -- Environment
Terrestrial-- Chemicals Monitoring & Transport-- (-1989)
54 ENVIRONMENTAL SCIENCES
ACIDIFICATION
ADSORPTION
ANAEROBIC DIGESTION
BARYONS
BIOCONVERSION
CADMIUM
CARBON
CATIONS
CHARGED PARTICLES
CHEMICAL ANALYSIS
CHEMICAL COMPOSITION
CHEMISTRY
CLAYS
COMPLEXES
COPPER
DATA
DIGESTION
ELEMENTARY PARTICLES
ELEMENTS
EXPERIMENTAL DATA
EXTRACTION
FERMIONS
FILTRATION
GEOCHEMISTRY
HADRONS
INFORMATION
INORGANIC ION EXCHANGERS
ION EXCHANGE MATERIALS
IONS
LIGANDS
MANAGEMENT
MATERIALS
METALS
MONTMORILLONITE
NICKEL
NONMETALS
NUCLEONS
NUMERICAL DATA
ORGANIC COMPOUNDS
PH VALUE
POTENTIOMETRY
PROCESSING
PROTONS
SEPARATION PROCESSES
SEWAGE
SEWAGE SLUDGE
SLUDGES
SOLUBILITY
SOLVENT EXTRACTION
SORPTION
TITRATION
TRANSITION ELEMENTS
WASTE MANAGEMENT
WASTE PROCESSING
WASTES