Comparison of mineral acid pretreatments for sulfide removal

• Published in: Journal AWWA
• Main Authors: Duranceau, Steven J., Anderson, Robert K., Teegarden, Robert D.
• Other Authors: Orange County Utilities
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 1999
• Subjects: Carbonic acid
• Online Access: http://dx.doi.org/10.1002/j.1551-8833.1999.tb08637.x; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fj.1551-8833.1999.tb08637.x; https://awwa.onlinelibrary.wiley.com/doi/pdf/10.1002/j.1551-8833.1999.tb08637.x

Both sulfuric and carbonic acid improved sulfide removal by lowering pH, but only carbonic acid preserved alkalinity and proved less corrosive. To determine water quality effects on groundwater treatment for hydrogen sulfide, the authors compared sulfuric acid (H 2 SO 4 ) and carbonic acid for pH adjustment pretreatment in a pilot‐scale (40‐gpm [2.5‐L/s]) randomly oriented packed tower. Pretreatment with either H 2 SO 4 or carbon dioxide (CO 2 ) to pH 6.0 resulted in > 95 percent sulfide removal for tower feedwater sulfide concentrations of 2.5 mg/L. However, utilization of H 2 SO 4 for pH adjustment resulted in a loss of alkalinity in the finished water and an increase in sulfur (as sulfate), whereas CO 2 pretreatment preserved alkalinity in the finished water and did not increase sulfur (as sulfate).