title: Sludge dewatering with cyclodextrins.
abstract: Cyclodextrins (CDs) increase the cake solids and drainage rate of belt-pressed biological or primary sludge when added to the sludge slurry along with conventional conditioning chemicals. These benefits are obtained at very low CD dosage. A 2.8 percentage point increase in cake solids was obtained in a full-scale trial with mixed primary and biological sludge from a paper mill. CDs also decrease the specific resistance to filtration and increase the capture rate of solids during belt pressing. Mechanistic studies showed that CDs increase the surface tension of c-PAM polymers in water and reduce the turbidity, indicating that they are able to aggregate the charged polymers, and, by inference, sludge particles treated with the polymer. A mechanism is proposed where CDs reduce excessively charged regions of the polymer-treated surface of the sludge, thereby facilitating its flocculation.
authors.affiliation: Institute of Paper Science and Technology, School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA 30332-0620, USA.
authors.forename: Bradley H
authors.initials: BH
authors.lastname: Hartong
authors.forename: Malyuba
authors.initials: M
authors.lastname: Abu-Daabes
authors.forename: Tuan
authors.initials: T
authors.lastname: Le
authors.forename: Motasem
authors.initials: M
authors.lastname: Saidan
authors.forename: Sujit
authors.initials: S
authors.lastname: Banerjee
mesh_terms: D001696:Biomechanical Phenomena; D003505:Cyclodextrins / Q000737:chemistry*; D057927:Hydrophobic and Hydrophilic Interactions; D007220:Industrial Waste; D010209:Paper; D011108:Polymers / Q000737:chemistry; D012722:Sewage / Q000737:chemistry*; D013500:Surface Tension / Q000187:drug effects; D018505:Waste Management / Q000379:methods*; D014934:Wood
chemical_list: D003505:Cyclodextrins; D007220:Industrial Waste; D011108:Polymers; D012722:Sewage