This powerpoint presentation begins by providing a brief overview of disinfection byproducts (DBP), along with stand pipe aeration and chlorine contact basin aeration as potential solutions for controling DBPs in small water systems. Aeration kinetic basics of equilibrium are presented, along with Henry's Constant Temperature
Correction Equation. Experimental methodology included a bench-scale study of diffused aeration to assess selected design variables of air flow rate, contact time (air/water ratio), diffuser
arrangement (bubble size), and selected operating conditions including air temperature, water temperature, and THM concentration. Bench scale experimental
conclusions:
water temperature and air to water ratio
have a significant effect on removals;
air temperature and initial concentration
did not have a significant effect on
removals; and,
bubble distribution did not appear to have
a significant effect on overall removals. The diffused aeration assessment summary indicates: a simple air diffuser can be placed in a storage tank or
chlorine contact basin for THM removal;
effective for small system THM compliance;
no removal of HAAs;
most effective for chloroform; and,
most effective during warm weather months. A pilot-scale study on spray aeration included:
evaluating the role of temperature on spray aeration
removal rates;
developing a relationship between percent removals and
physical characteristics of aeration equipment with
respect to Henry's constants of THM species; and,
assess the role of operating parameters (e.g. operating
pressure / head loss and flow rate) in determining mass
transfer coefficients and interfacial surface area (KLa). Spray aeration pilot schematic is presented, and conclusions indicated: aeration provides a way to remove THMs after they
have formed with a minimal capital investment;
temperature has a significant effect on removal
efficiencies;
diffused aeration can achieve significant removals
based on air to water ratio; and,
spray aeration can achieve significant removals of
THMs dependent primarily on shower head type and
droplet travel distance. Includes tables, figures.
| Edition : | Vol. - No. |
| File Size : | 1
file
, 2.9 MB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 40 |
| Published : | 11/01/2009 |
