Arsenic and boron removal from spring and groundwater samples in boron mining regions of Turkey by electrocoagulation and ion-exchange consecutive processes

Abstract

a b s t r a c tBoron (B) and arsenic (As) are two important contaminants detected in the spring and groundwater around the Bigadiç borate mines in Turkey which have the largest colemanite and ulexite deposits in the world. In this study, electrocoagulation (EC) process was used for the removal of arsenic from waters since EC was capable of removing arsenic to trace levels. The removal efficiencies of arsenic from spring and groundwater samples containing different arsenic concentrations of 36-1021 µg/L at 0.025-0.10 A and operating time of 0-60 min were achieved >97-99.9% at 2-16 min for Fe plate electrodes to meet the permissible level of arsenic effluent concentration of <10 µg/L. Energy and electrode consumptions for arsenic removal efficiency were 0.00429 kWh/m 3 and 0.00372 kg/m 3 for 0.025 A, 0.00529 kWh/m 3 and 0.00496 kg/m 3 for 0.05 A, and 0.00917 kWh/m 3 and 0.00992 kg/m 3 for 0.10 A. However, the EC was unsuccessful for the removal of B. B removal efficiencies at 0.025, 0.05, and 0.10 A were determined as 3.4, 3.9, and 4.6%, respectively. Effluent pH values were noticed to increase from 8 to 10 during the EC process and this was an advantage to remove B from the sample using ion-exchange process at pH 8-11. For that reason, Amberlite IRA-743 ion-exchange resin was selected to treat B in the effluents and effect of resin dosage (0.025-3 g) on the B removal efficiency was performed. A removal efficiency of 99-100% for B in the spring and groundwater samples was obtained. As the resin dosages were increased from 0.025 to 3 g, adsorption capacity was observed to decrease from 60 to 7.4 mg B/g resin. As effluent concentration of 1 mg/L was considered, amount of resin dosage for B removal was 0.75 g to reduce B concentration from 90.11 to 0.56 mg/L. The EC and ion exchange processes together were very successful for the removals of arsenic and boron from natural waters in the boron mining regions.

Adsorption of arsenic from aqueous solution using a zero-valent iron material modified by the ionic liquid [Hmim]SbF6

“…3.2.1 Effect of reaction temperature. In order to investigate the effects of reaction temperature on the As(V) removal efficiency, adsorption experiments were conducted at six different temperatures (10,20,30,40, 50 and 60 C). In this experiment, 6 0.5 g portions of H/Fe were weighed out, and each was added to 1.0 L of arsenic-containing wastewater with an arsenic concentration of 1 mg L À1 .…”

“…7 Current treatment technologies for arsenic-containing water mainly include precipitation, adsorption, ion exchange, neutralization oxidation, ion otation, electro-occulation, extraction, membrane separation and biological method, among others. [8][9][10][11][12] Among them, due to its advantages of simplicity, low cost and environmental friendliness, adsorption is the most commonly used method to remove arsenic from wastewater. Various types of adsorbents have been discussed.…”

Physico‐Chemical Processes

“…Electrocoagulation with iron plate electrodes were investigated, and Kobya et al (2017) found that the removal for arsenic could reach 97% to 99% in spring and groundwater samples. Addition of chemicals before the sedimentation exhibited different effects on particle settling.…”

Removal of arsenic in groundwater from western Anatolia, Turkey using an electrocoagulation reactor with different types of iron anodes

“…Recently, As removal efficiency as high as >99% through the electrocoagulation (EC) process has been reported for many drinks of water and wastewaters ( Song et al., 2017 ; Kobya et al., 2017 ; Alcacio et al., 2014 ; Amrose et al., 2013 ; Molgora et al., 2013 ; Vasudevan et al., 2010 ; Parga et al., 2005 ). In the EC process, Electrochemical dissolution of sacrificial metal electrodes generates metallic hydroxide flocks within the water.…”