An electrochemical cell containing a sacrificial electrode suitable for electrocoagulation as well as an electrocoagulation process for removing various pollutants from water or wastewater by the use of the electrochemical cell. Also, the sacrificial electrode itself. Several electrochemical cells can be coupled to an electrochemical cell assembly. Certain aspects and embodiments are especially suitable for reduction of fluoride or fluoride in combination with heavy metals such as hexavalent chromium or arsenic.