Production of a new wastewater treatment coagulant from fly ash with concomitant flue gas scrubbing

• Published in: Journal of hazardous materials Vol. 162; no. 2; pp. 1430 - 1437
• Main Authors: Li, Ling, Fan, Maohong, Brown, Robert C., Koziel, Jacek A., van Leeuwen, J.(Hans)
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 15.03.2009; Elsevier
• Subjects: Applied sciences; Atmospheric pollution; Carbon; Coagulant; Coal Ash; Exact sciences and technology; Fly ash; Gases; General processes of purification and dust removal; General purification processes; Industrial Waste; Microscopy, Electron, Scanning; Particulate Matter; Pollution; Prevention and purification methods; SO 2 removal; Wastewater treatment; Wastewaters; Water Pollutants; Water treatment and pollution; Coagulant; Fly ash; SO 2 removal; Wastewater treatment; SO2 removal; Chlorates; Scrubbing; Sulfates; Sulfur dioxide; Waste water; Gaseous effluent; Iron III; Flocculation reagent; Flocculation; Production; Turbidity; Air pollution; Physicochemical purification; Waste water purification
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2008.06.035

The research focused on the production of a complex wastewater coagulant containing polymeric sulfates of aluminum and iron from fly ash. At the same time, SO 2 in the simulated flu gas was removed by absorption in a fly ash slurry and oxidized with sodium chlorate. Extraction efficiency of iron and aluminum oxides from fly ash was affected greatly by reaction temperature and time. The extraction efficiency increases as temperature increases. Removal efficiency of SO 2 was influenced by temperature, SO 2 feed concentration and feed gas dispersing method. The produced complex coagulant containing both polymeric ferric sulfate (PFS) and polymeric aluminum sulfate (PAS) was proven to be effective in removing total suspended solids (TSS) and turbidity in wastewater. The complex coagulant is more effective than conventional iron and aluminum sulfates in turbidity removal.