ABSTRACT
The selected site for the pilot plant had an initial arsenic concentration of about 1.9 mg/L. Figure 1 shows the reduction of the Astot-concentration and the used FeCl2-dosage. The Astot-concentration declined to less than 0.4 mg/L at the initial infiltration rate of 2.5 m3/h and the discharge rate of 0.5 m3/h within less than one year. The final FeCl2-dosage was 500 mL/cycle at the end of the first year. Doubling the discharge
1 INTRODUCTION
The groundwater at the investigated military site in Northern Germany is contaminated with arsenic (As)-containing chemical warfare agents which were produced during both world wars. The total As-concentrations (Astot) at the site reach up to 9 mg/L (Holländer et al., 2008). Astot is predominantly organically bound As (Asorg) and thus mainly occurs in the form of phenylized As compounds. Inorganic compounds (Asinorg: As3+ and As5+, each <10%) are also present.
