PLANT CONSTRUCTION

Filter system for use in removal of manganese

This special filter material consists of a mixed oxide and can be used for a reliable removal of manganese at pH values greater than or equal to 6.5. It enables an elevated charging at minimal contact time and elevated filtration rates. DOSFILT is stable against carbonic acid, needs not to be reactivated, replaced or refilled and requires no training periods. After flushing, the clean water agrees as well with the aim of treatment. With increased amounts of iron we use DOSFILT as a lower layer in a multilayer filter. The main quantity of iron is deposited in the layer lying above it (e.g. anthracite coal). The reaction layer remains unprotected. Due to the stability against carbonic acid and due to the properties of DOSFILT, manganese reliably can be removed at very low pH values. Additionally, in most cases there is no need to increase the pH value before the removal of manganese.

Example of application AQUADOSIL filter (click for full view)

Scheme

1. step: entry of oxygen (if necessary) 2. step: : filtration to remove iron and manganese (DOSFILT) 3. step: physical high-performance deacidification (AQUADOSIL plant) This combination is a low-cost and maintenance-poor process reliable in operation. The entire treatment occurs without hydraulic interruption using raw water pumps (see illustration above). After validation of the new drinking water regulation (TrinkwV, 01.01.2003), this simple process also can be applied to soft and medium hard water because a hardening of this water is not necessary due to modified requirements to the pH value (ph-value 7,7 or dissolving capacity of calcite 5 mg/l).

Technical data

colour: black shape: granular granularity: appr. 0,5 - 1,3 mm bulk density: appr. 2 kg/l

Operational hints

filtration rate: 10 to 15 m/h flushing rate: 65 m/h (water) expansion of filter bed: > 15% loss of material: lower than 1%/Year