Implementation of electrocoagulation for reduction of Zn in an outlet stream from waste incineration plant
Abstrakt
The paper is focusing on the full-scale operation of electrocoagulation for Zn removal from wastewater with origin in a municipal incineration plant. The process was custom designed for continuous full-scale operation.
Total capacity of the process varied between 1200 and 1400L/h. This was achieved by two simultaneous elec-trocoagulation cells operated in parallel.
Residual concentrations of Zn in the treated water were consistently lower than 0.5 mg/L during the testing period. Residual concentrations of Zn and other accompanying con-taminants were reduced below the desired limits (current limit for Zn in outlet water is 1.5 mg/L).
The process cost was critically assessed. The electricity consumption for the operation of electrocoagulation cells is 0.75-1.1 kWh/m3 of purified water.
A more significant expense is the consumption of electrode cartridges. The service life of electrode cartridges with a plate thickness of 5 mm is about 1 200 m3 of water/electrode pack, which rep-resents a cost of around 0.6-1 EUR/m3 out of total 1.6 EUR/m3 of purified water.
Waste incineration plants usually produce their own electricity therefore technologies like electrocoagulation become affordable and competitive.