Fluoride Removal From Drinking Water by Electrocoagulation Using Iron and Aluminum Electrodes

Abstract

Background: Existence of fluoride in drinking water above the permissible level causes human skeletal fluorosis. Objectives: Electrocoagulation by iron and aluminum electrodes was proposed for removing fluoride from drinking water. Materials and Methods: Effects of different operating conditions such as treatment time, initial pH, applied voltage, type and number of electrodes, the spaces between aluminum and iron electrodes, and energy consumption during electrocoagulation were investigated in the batch reactor. Variable concentrations of fluoride solution were prepared by mixing proper amounts of sodium fluoride with deionized water. Results: Experimental results showed that aluminum electrode is more effective in fluoride removal than iron, as in 40 minutes and initial pH of 7.5 at 20 V, the fluoride removal process reached to 97.86%. The final recommendable limit of fluoride (1.5 mg/L) was obtained in 10 minutes at 20 V with the aluminum electrode. Conclusions: In electrocoagulation with iron and aluminum electrodes, increase of voltage, number of electrodes and reaction time as well as decrease of the spaces between electrodes, enhanced the fluoride removal efficiency from drinking water. In addition the effect of pH and initial concentration of fluoride varied with types of electrodes.

Biosorption of Heavy Metal From Cadmium Rich Aqueous Solutions by Tea Waste as a Low Cost Bio-Adsorbent

“…All the chemicals were purchased from Merck company (Germany). The experimental stages were conducted at 30°C and the remained concentration of the metal was determined by atomic absorption spectrophotometer (PG model, England) (22). It is important to consider that all the experiments were replicated three times and the mean of data and the results were determined and used.…”

Electrocoagulation as a Promising Defluoridation Technology from Water: A Review of State of the Art of Removal Mechanisms and Performance Trends

“…Bazrafshan et al [38] determined that energy consumption was close to each other when using iron and aluminium electrodes for the same operating conditions. On the other hand, Takdastan et al [93] found that the iron electrode's energy consumption was almost quadruple as high as the aluminium electrode (5590 kwh kg −1 F − and 1435 kwh kg −1 F − , respectively) in the same conditions. Ün et al [56] concluded that increasing the time to 30 min and the current density to 3 mA cm 2 led to an increase in fluoride removal efficiency of up to 85.9% from water, which resulted further increase in the energy consumption of the process from 4 to 12.5 kWh m −3 .…”

“…For this reason, several researchers are moving toward combined EC processes to increase pollutants removal efficiency, such as fluoride found in drinking water. EC process can be used as a pre-or post-polishing process depending on the type of contaminants present in water [101][102][103][104][105].…”

Optimization of the Parameters Influencing the Photo-Fenton Process for the Decolorization of Reactive Red 198 (RR198)

“…The photo-fenton oxidation process can be used as a suitable method for the removal of highly contaminated waters that contain large amounts of 3-Aminopyridine compound, and the removal rate can be augmented by increasing the reaction time (38). The fact that dye removal rates can be enhanced by increasing the reaction time (39) can be attributed to the high production of the OH°. Another study showed that the Fenton process was able to decolorize textile wastewater at 20 -40 minutes reaction time.…”