2.2. Zero-valent iron
The ZVI powder (purity >98%, 400 mesh) must be acid-washed
before using in order to remove the surface oxides or other
impurities. The ZVI powder was mixed with a 10% hydrochloric
acid solution for 2 min, then rinsed with N2-sparged deionized
water and acetone, finally dried under N2 gas. The specific surface
area of the acid-washed iron was 0.167 m2/g according to the
Brunauer–Emmett–Teller (BET) test.