Phosphorus removal from wastewater: energy demand in electrochemical process

The electrochemical process (EP) as an advanced treatment method has been widely applied to the removal of pollutants from wastewater streams. Several studies have investigated the efficiency and optimization of the electrochemical method for removing phosphorus compounds from aqueous solutions. However, the energy demand for this method has only been reported in limited studies. Therefore, this research aimed to determine the energy consumed during an electrochemical process to remove organic phosphorus from wastewater. This experimental bench-scale study was carried out in a batch system on 180 samples of phosphorus contaminated wastewater. In order to prepare synthetic wastewater samples, containing 2-32 mg/L organic phosphorus, adenosine monophosphate salt was added to the dechlorinated tap water. The wastewater samples were then subjected to treatment in an electrolytic cell which consisted of steel electrodes. Electricity power was immobile at 0.6 A DC (1.15 mA/cm(2)). The remaining phosphorus was examined by 4500P.D method described in 21st Edition of Standard Methods for Examination of Water and Wastewater. A mixed design analysis of variance test with repeated measurements by SPSS16 software was applied for data analyzes. The results showed that, the EP using steel electrodes is capable of removing organic phosphorus up to 98%. For the diminution of phosphorus from samples to less than 1 mg/L, the mean of maximum energy demands was about 0.59 kWh/g of removed organic phosphorus. The energy demand can be calculated by the suggested graphs depending on the initial concentration of organic phosphorus.