Floc structure and the role of cations

• Published in: Water Science & Technology Vol. 44; no. 10; pp. 209 - 213
• Main Authors: NOVAK, J. T, MULLER, C. D, MURTHY, S. N
• Format: Conference Proceeding Journal Article
• Language: English
• Published: London IWA Publishing 01-01-2001
• Subjects: Aerobic digestion; Anaerobic digestion; Anaerobic treatment; Anatomical structures; Applied sciences; Biopolymers; Cations; Chemical oxygen demand; Dewatering; Digestion; Exact sciences and technology; Flocculation; Iron; Iron - chemistry; Other industrial wastes. Sewage sludge; Pollution; Polymers; Proteins; Proteins - chemistry; Sewage - chemistry; Shear tests; Sludge; Sludge digestion; Sludge drying; Solubility; Solubilization; Stability; Wastes; Water - chemistry; Water Movements; Waste treatment; Flocculation; Cations; Conditioning; Dehydration; Flock; Structure; Sewage sludge; Protein
• ISBN: 9781843394044; 1843394049
• ISSN: 0273-1223; 1996-9732
• DOI: 10.2166/wst.2001.0622

Cations have been found to influence the settling and dewatering characteristics of biological sludges. This research was directed at investigating the role of iron in floc stability of sensitivity to shear and in the response to anaerobic and aerobic digestion. Our data shows that iron may contribute to floc strength and it appears that the deterioration in sludge dewatering during anaerobic digestion is associated with the reduction and solubilization of iron. Further, it is the presence of proteins in solution that contributes to poor dewatering and to the demand for conditioning chemicals. The addition of iron for improving dewatering shows that iron may selectively coagulate solution proteins.