Electrochemical treatment of industrial cooling tower blowdown water using magnesium-rod electrode

• Published in: Water resources and industry 2020-06, Vol.23, p.100121, Article 100121
• Main Authors: Abdel-Shafy, Hussein I., Shoeib, Madiha A., El-Khateeb, Mohamed A., Youssef, Ahmed O., Hafez, Omar M.
• Format: Article
• Language: English
• Subjects: Cooling tower blowdown water; Electrocoagulation; Magnesium-rod electrode; Operating cost; Scale ions removal; Sludge characterization
• ISSN: 2212-3717; 2212-3717
• DOI: 10.1016/j.wri.2019.100121

Cooling tower blowdown water (CTBW) was treated with simple electrocoagulation (EC) using magnesium-rod electrode. This study examined the effects of the treatment parameters (current density, electrolysis time, electrode distance, initial pH and stirring speed) on the EC ability to remove hardness ions (Ca2+, Mg2+) and dissolved silica from CTBW. Under the optimized condition, magnesium-rod electrode removed 51.80% and 93.70% respectively for total hardness and silica; with an operating cost of 0.88 US$/m3 treated CTBW. EC sludge has been characterized by SVI, SEM-EDX, XRD, and FTIR exploring the ability of sludge to settle, surface morphology, elemental composition, crystalline type, and functional groups. It can be concluded that EC using magnesium-rod electrode can be successfully applied for the treatment of CTBW to facilitate its reuse. [Display omitted] •Electrocoagulation (EC) has been employed for the removal of scale ions from CTBW using magnesium-rod electrode.•Various parameters were studied and the results showed that EC process effectively removed hardness and silica from CTBW.•In order to rationalize the removal mechanism, the EC generated sludge was characterized by SVI, SEM-EDX, XRD, and FTIR.•Removal efficiency of 51.80% and 93.70% was achieved for hardness and silica respectively using magnesium-rod electrode.