Nitrate Removal From Groundwater Using Continuous Flow Electrocoagulation Reactor

Abstract

Nitrate contamination of groundwater is a major concern due in large part to excessive use of nitrate-based chemical fertilizers. It can be noticed that all countries and organizations restricted nitrate concentration in drinking water within the range 45-50 mg-NO3/L. The purposes of this study is nitrate removal from aqueous solution by Electrocoagulation process.Then find the best operating conditions and apply to the northern Gaza water samples. A laboratory continuous flow electrocoagulation reactor was designed to investigate the effects of different parameters on the removal of nitrate from aqueous solution. Influence of process parameters such as initial nitrate concentration (Ci), hydraulic retention time (HRT), distance between electrodes (D), applied voltage (V) and effective area of anode (Aeff). The best operating conditions for nitrate removal for the aqueous solution were found to be at HRT 2, 2.5 and 2.5hours, applied voltage 40V, distance between electrode 3cm and effective area of electrode 47.1, 47.1 and 61.4 cm2, when initial nitrate concentration were 100, 150 and 200 mg-NO3/L, respectively. Moreover, obtained best conditions were tested on original groundwater sample from the northern of Gaza water distribution system. It was found that the nitrate removal efficiency was reached to 80 % at the best conditions: V = 40V, HRT = 2.5hours, D = 3cm and Aeff = 61.4cm2, when TDSi and Ci were 1000 mg/L and 200mg-NO3/L , respectively. Therefore, this process is suggested as an efficient alternative technique on nitrate removal from aqueous solution. And also it was possible to remove nitrate from groundwater below the limit of the drinking water standard using this method. And also there are many side benefits that can be achieved when using EC, such as that the alkalinity, total hardness concentration and TDS were decreased when using the EC in groundwater.