Minimizing aluminum residuals in plants using
alum-based coagulants can help to minimize the
potential of aluminum postprecipitation in the
distribution system. Reducing precipitation potential
can help to minimize the financial and public health
risks associated with the formation of precipitates in
water transmission and distribution systems. This
article examines the ability of orthophosphate, which
is known to interact with aluminum at concentrations
commonly found in drinking water, to reduce
soluble aluminum levels through the coagulation/
flocculation/separation process. An alternative use
for orthophosphate as an aluminum control method
is proposed. In bench-scale tests, orthophosphate
addition during rapid mix showed the consistent
ability to reduce residual aluminum concentration
when using alum as a coagulant. Adding orthophosphate
in bench-scale tests reduced residual dissolved
aluminum concentrations by as much as 350 µg/L.
The effect of orthophosphate addition varied with
dose, pH, temperature, and chemical addition
sequence. Includes 25 references, tables, figures.
| Edition : | Vol. 96 - No. 9 |
| File Size : | 1
file
, 150 KB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 11 |
| Published : | 09/01/2004 |
