Dental wastewater treatment using electro-chemical coagulation unit process

• Published in: Separation science and technology Vol. 60; no. 9-10; pp. 1171 - 1188
• Main Authors: Mahesh, Sahana, Benamanahalli Motaiah, Krishna, Shivaswamy, Mahesh, Nandigunda Subramani, Manasvi, Kumar Jain Shanthilal, Vikram
• Format: Journal Article
• Language: English
• Published: Abingdon Taylor & Francis 03.07.2025; Taylor & Francis Ltd
• Subjects: Aluminum; Chemical coagulation; Chemical oxygen demand; Coagulation; COD; Contaminants; Dissolved solids; Effluent treatment; electrochemical coagulation (ECC); Electrolysis; Energy consumption; energy cost; Magnesium; Oxygen requirement; point of zero charge (PZC); Pollutant removal; Raw dental wastewater; Rivers; Sludge; Sludge drying; solids mass balance; Stainless steel; Stainless steels; Total dissolved solids; Waste management; Waste streams; Wastewater treatment; X-ray spectroscopy
• ISSN: 0149-6395; 1520-5754
• DOI: 10.1080/01496395.2025.2483761

Raw dental wastewaters (DWW) of two kinds were treated by electrochemical coagulation (ECC) technology using stainless steel (SS) electrodes for cell currents of 0.3A and 0.7A. EDS of raw DWW showed nine elements: Na, Al, Ca, Mg, K, Si, C and O. Acidic raw DWW (DWW-A) showed low response during ECC for chemical oxygen demand (COD), total dissolved solids (TDS), chloride removal etc. whereas near-neutral DWW stream (DWW-N) offered reasonably high removal of pollutants/contaminants from waste stream in <60 min electrolysis time. DWW-A stream showed 70% COD removal for 0.7A and 30% for 0.3A. DWW-N removed COD by 50% and 94% for 0.3A and 0.7A cell current giving clear water treated effluent. Electron dispersive X-ray spectroscopy (EDXS) of ECC sludge showed: carbon, oxygen, and DWW-N (0.7A). ECC dry sludge (DS) for DWW-A were 369 and 309 g/m 3 of DWW treated for 0.3A and 0.7A. Similarly, ECC-DS for DWW-N were 173 and 123 g/m 3 for 0.3A and 0.7A. EDXS of ECC sludge showed ~ 52%O and 11%C. It was concluded that ECC serves as a pretreatment option when raw DWW is acidic and as the main treatment for DWW-N. Energy consumption for DWW-N for 0.3A and 0.7A were 5.82 and 24.22 kWh/m 3 . This research work presents the use of novel electrochemical coagulation technology as a treatment process for remediating raw dental wastewaters (DWW) of two different streams using stainless steel (SS) two-dimensional plate electrodes. The experimental results showed a good response for near-neutral DWW stream effectively removing COD, chloride, TDS, and total alkalinity. ECC sludge was subject to detailed analyses applying mass balance. The energy consumption of the EC process was estimated. The experimental results showed the applicability and efficacy of the ECC process.