Electrochemical treatment of nutrient containing solutions

Abstract

Electrochemical methods of water treatment are becoming a more economical alternative towards a sustainable way of providing clean water. Electrochemical treatment of water takes advantage of conventional principles such as precipitation, flotation, and coagulation. This technology can have significant contributions in water and wastewater treatmentfacilities. Wastewater treatment facilities can in turn contribute to circular economy by the recovery of valuable nutrients.

The aim of this research was to investigate the potential of electrochemical treatment of nutrient containing solutions. The focus was to recover phosphorus as struvite from livestock and nutrient containing synthetic solutions. In the investigation, electrocoagulation-electroflotation was used. The corrosion behavior of magnesium anode used was investigated using Tafel extrapolation method. Galvanostatic measurements werethen conducted to study the efficiency of the system. The current densities used forgalvanostatic experiments were 2.5, 5.0 and 7.5 mA/cm2.

After phosphorus recovery, the quality of used synthetic solutions was found to pass therequirements for nutrient removal inwastewater treatment set by Finnish Ministry of the Environment. Records of conductivity and pH from each experiment shown that pH plays an important role in monitoring nutrient recovery.