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ELECTROCOAGULATION
NO FIELD INFORMATION
1 Purpose andstatus
Electrocoagulation produces coagulants directly into the water by the release ofmetal ions such as iron or aluminium by electrolysis of electrodes by applyingdirect electrical current.
It is an experimental technology.
2 Alternatives Standard metals coagulation
3 Summary of key features
Experimentation on Vaal Dam water with a turbidity of 60 NTU with micro-organism added.
Turbidity reduced to
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6 Performancelimitations
Floating debris that could interfere physically with the electrodes must beremoved prior to treatment.Plant performance is highly dependant on climatic conditions; lack of wind andlow solar radiation levels reduces the efficiency and output. Hihg raw waterturbidity may require a reduction in through put.
7 Recommendedcapacity
From very small to large plantsExpansion is easy but costly [modular].
8 Operationalrequirements
Requires a submersible pump and semi-skilled operator with basicunderstanding of water quality and elementary plumbing.
9 Maintenancerequirements Removal of scale form the electrodes, removal and disposal of chemical sludge,and cleaning of filter.
10 Infr ast ruc tu rerequirements
Solar panel, wind generator and treatment units are factory manufactured anderected on site.Stands for wind generator, solar panel and treatment units, gravity flowrequired.Disposal of iron or aluminium rich sludge.
11 Impact of failures
Not dependant on electricity supply when using wind or solar power.
12 Energyrequirements
Electricity is generated on site form renewable sources i.e. wind and solarpower.
13 Capital costs Still being determined.
14 Operating costs Still being determined (but expected to be low).
15 Typicaltreatmentprocessconfiguration(train) orexample
16 Exampl es of SAinstallations
Experimental only at Rand Water.
17 Socio-
economicaspects
Operating costs are reduced by using renewable energy sources, which can be
easily maintained by the community.
18 Resear ch andevaluation inSouth Africa
Rand Water
Final waterstorage tank
FiltrationElectrocoagulation
Sedimentation
Rawwater Disinfection