Sludge dewatering with cyclodextrins.
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.
Hartong
Bradley H
BH
Institute of Paper Science and Technology, School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA 30332-0620, USA.
Abu-Daabes
Malyuba
M
Le
Tuan
T
Saidan
Motasem
M
Banerjee
Sujit
S
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
D003505:Cyclodextrins; D007220:Industrial Waste; D011108:Polymers; D012722:Sewage