4. Conclusion
A continuous bipolar electrocoagulation–flotation system
was developed for the treatment of high fluoride-contentwastew-
ater following calcium precipitation with SDS. Wastewater
could be effectively treated by the system, but a higher dose of
SDS than batch systemwas needed. The tendency of SS removal
and residual [F−] with Qe in the batch and continuous ECF sys-
tems were similar, but SS removal in the continuous system was
less than that in the batch system. SS removal dropped when
too much or too little hydrogen gas was produced during ECF.
The continuity of flow broke when ΓG/L was over 0.4, and the
flotation ability was not enough to float all of the SS when ΓG/S
was under 0.1 L/g in the continuous ECF system.