Affordable Access

Effect of coagulant types on textile wastewater reclamation in a combined coagulation/ultrafiltration system

Authors
Journal
Desalination
0011-9164
Publisher
Elsevier
Publication Date
Volume
202
Identifiers
DOI: 10.1016/j.desal.2005.12.063
Keywords
  • Coagulation
  • Textile Wastewater
  • Ultrafiltration
  • Membrane Fouling
  • Water Reuse
Disciplines
  • Chemistry

Abstract

Abstract A combination of coagulation and ultrafiltration (UF) processes for textile wastewater reclamation was investigated using various types of coagulating chemicals such as polyamine, alum, polyaluminum chloride (PACl), and ferric salts. The potential of the combined system was evaluated to replace the existing treatment processes which are composed of a flotation tank (primary step) and a series of filtration beds including sands, granular carbons, and diatomaceous powders. Regardless of the type and dosage of the coagulants, the UF system achieved substantial colloidal particle removal (>97% of turbidity was removed), but membrane fouling was mitigated in a different manner. The degree of fouling reduction was highly dependent upon the type of coagulants used, even though the turbidity and organics removal efficiencies were nearly the same. The polymeric coagulant aggravated membrane fouling, whereas the inorganic coagulants always helped reduce fouling. A residue of the coagulating polymer, which was added in the primary step and its concentration in the effluent was at an immeasurable level, was found to cause serious membrane fouling. The use of polymeric coagulants should be prevented or minimized if UF is considered for textile wastewater reclamation. Polymerized aluminum was found to be the most effective among the coagulants tested, although ferric salt was better than alum in controlling fouling. In particular, it seemed that the characteristics of coagulation chemistry and the coagulated particles had a great impact upon membrane fouling.

There are no comments yet on this publication. Be the first to share your thoughts.