|
Procedure
|
Treatment Steps
|
Coarse
fraction (%)* |
|||||
|---|---|---|---|---|---|---|---|
| 1 | Soak 2 hr | Sonicate | Wash/dry | Soak 15 hr | Sonicate | Wash/dry | 5.0 |
|
|
Calgon sol.† | 40 s |
|
Calgon sol. | 90 s |
|
|
| 2 | Soak 2 hr | Sonicate | Wash/dry | Soak 1.5 hr |
|
Wash/dry | 13.1 |
|
|
20% bleach‡ | 40 s |
|
75% bleach |
|
|
|
| 3 | Soak 2 hr | Sonicate | Wash/dry | Soak 15 hr | Sonicate | Wash/dry | 9.0 |
|
|
20% Cascade** | 40 s |
|
75% Cascade | 90 s |
|
|
| 4 | Soak 2 hr |
|
Wash/dry | Soak 1 hr |
|
Wash/dry | 10.9 |
|
|
100% bleach |
|
|
100% bleach |
|
|
|
Notes: * = Coarse fraction is the % (by weight) of the initial ~5 g of material that was left at the end of the procedure. † = Calgon-peroxide solution (pH = 6) prepared by mixing 175 g sodium hexametaphosphate, 2 liters of ~35% hydrogen peroxide (pH < 4) and 18 liters deionized water (pH = 5). ‡ = Ultra Clorox regular bleach manufactured by The Clorox Company. This is 94% water, 6% sodium hypochlorite, and trace sodium hydroxide (pH = 11.4 for the undiluted product). ** = Cascade Pure Rinse Gel dishwasher detergent manufactured by Procter and Gamble. This is 90% water, 5%–10% sodium silicate, and 1%–5% of each of the following: sodium hypochlorite, potassium hydroxide, sodium hydroxide (pH = 11.7 for the undiluted product).