Specific chemical interactions between metal ions and biological solids exemplified by sludge particulates.
The adsorption of metals onto biological surfaces was studied exemplified by municipal sludge particulates of the primary, the secondary, and the tertiary sludge types from four regional wastewater treatment plants. Major factors affecting the extent of metal adsorption including pH, DOM, total biomass, and total metal loading were studied. The acidity-basicity characteristics of the DOM, the metal ions (Lewis acids), and the surface of the sludge particulates make pH the most important parameter in metal adsorption. Change in pH can modify the speciation of the metal ions, the DOM, and the surface acidity of the sludge particulates and subsequently determines the degree of metal distribution between the aqueous phase and the sludge solids. Information on the acidity-basicity characteristics of the DOM and the sludge particulates are used to calculate the stability constant of metal ion-sludge complexes.
Department of Civil and Environmental Engineering, University of Delaware, Newark, DE 19716, USA. Electronic address: huang@UDel.Edu.
C P
CP
Huang
Department of Civil, Architectural & Environmental Engineering, Missouri University of Science and Technology, Rolla, MO 65409, USA.
Jianmin
J
Wang
D007477:Ions; D008670:Metals / Q000737:chemistry*; D009930:Organic Chemicals / Q000737:chemistry; D052638:Particulate Matter / Q000737:chemistry*; D012722:Sewage / Q000737:chemistry*
D007477:Ions; D008670:Metals; D009930:Organic Chemicals; D052638:Particulate Matter; D012722:Sewage
Dissolved organic matter (DOM); Metal ions; Sludge particulates; Surface acidity; Surface complex formation