Result 4 · Figure 6
In the spray-aerated open filter, the filter solids show manganese and nickel rising together. As the manganese oxide precipitates onto the grains, it sweeps the trace nickel out of the water.
Nickel concentration plotted against manganese concentration in 13 filter-solid samples drawn from the spray-aerated open filter (German: Fall-Verdüsungs-Filter) of Wasserwerk Breyell. The samples were digested with aqua regia (Königswasseraufschluss) per DIN 38414-S7 (Teil 4) and analysed by ICP-MS; both axes are reported in mg/kg of dried filter material. The strong positive correlation (r² = 0.66) is consistent with co-precipitation of dissolved Ni²⁺ onto the freshly formed MnO₂ surfaces that coat the half-burned dolomite grains during demanganization. *