1. Arsenic Removal from Drinking Water during Coagulation
- Author
-
Janet G. Hering, Pen-Yuan Chen, Menachem Elimelech, and Jennifer A. Wilkie
- Subjects
inorganic chemicals ,chemistry.chemical_classification ,Flocculation ,Environmental Engineering ,integumentary system ,Alum ,Inorganic chemistry ,chemistry.chemical_element ,Chloride ,chemistry.chemical_compound ,chemistry ,Environmental chemistry ,medicine ,Environmental Chemistry ,Ferric ,Water treatment ,Organic matter ,Sulfate ,Arsenic ,General Environmental Science ,Civil and Structural Engineering ,medicine.drug - Abstract
The efficiency of arsenic removal from source waters and artificial freshwaters during coagulation with ferric chloride and alum was examined in bench-scale studies. Arsenic(V) removal by either ferric chloride or alum was relatively insensitive to variations in source water composition below pH 8. At pH 8 and 9, the efficiency of arsenic(V) removal by ferric chloride was decreased in the presence of natural organic matter. The pH range for arsenic(V) removal with alum was more restricted than with ferric chloride. For source waters spiked with 20 μg/L arsenic(V), final dissolved arsenic(V) concentrations in the product water of less than 2 μg/L were achieved with both coagulants at neutral pH. Removal of arsenic(III) from source waters by ferric chloride was both less efficient and more strongly influenced by source water composition than removal of arsenic(V). The presence of sulfate (at pH 4 and 5) and natural organic matter (at pH 4 through 9) adversely affected the efficiency of arsenic(III) removal by ferric chloride. Arsenic(III) could not be removed from source waters by coagulation with alum.
- Published
- 1997
- Full Text
- View/download PDF