Performance of Continuous Electrocoagulation Process for Turbidity Removal from Sand Filter Backwash Water

Abstract

The presence of particles such as algae, clay, organic materials and water-soluble substances often create turbidity or color in water. In recent years, electrocoagulation process has attracted an extensive attention due to its advantages. Since sand filters are widely used in water treatment industry and their corresponding backwash water is large in volume, turbidity removal will save water consumption and its recycling. In this study, real samples of backwash water from sand filters of a water treatment plant in Alborz province were collected. The turbidity removal was further evaluated under operating conditions of 6, 12, 18 and 30 V as the exerted voltages, electrode distances of 1 and 1.5 cm, different initial turbidities (391 NTU as sample 1 and 175 NTU as sample 2), iron and steel as the sacrificial electrodes in a continuous electrocoagulation reactor. According to the results, the optimum conditions without considering the process economy was found to be 30 V, the iron electrode and electrode distance of 1 cm and samples 1 and 2 had an effective turbidity removal efficiency of 98.4 and 91.6%, respectively.

Turbidity Removal from a Model Solution by Continuous Mode Electrocoagulation and Evaluation of Energy Consumption

“…Another study where the effect on turbidity with increasing voltage, at all voltage levels, using aluminum as the anode showed a faster and higher turbidity removal than using iron as the anode [49]. In studies using aluminum, for three voltage levels, an increasing effect on turbidity reduction was observed as voltages were increased (1.5V, 2V and 2.5 V) [50]. In the research carried out, they compared iron and aluminum electrodes in the reduction of turbidity, obtaining greater turbidity removal using aluminum electrodes as opposed to iron [51].…”

Leaching Potential and Effectiveness of Pervious Mortar Filters in Bacteria and Turbidity Removal from Surface Water

“…Due to the small pores and their hydraulic characteristics, this porous composite can transmit water while effectively entrapping the pollutants carried, such as suspended solids, bacteria, and heavy metals. One method commonly used in surface water treatment especially for turbidity removal is coagulation using alum and ferric chloride along with calcium hydroxide as a coagulant to reduce turbidity (8). PMF can be an alternative method to reduce turbidity without using these chemicals.…”