Toxic herbal wastewater treatment by Fenton process

Abstract

The use of herbal medicine has a long history, herbal tablets and extracts play an important role in modern medicine. Radix Aconiti is one of the most commonly used herbal medicine, and its medicinal component (alkaloids) are extremely toxic, so Radix Aconiti needs to be processed before using. Accordingly, Radix Aconiti processing wastewater exhibits high toxicity due to the presence of alkaloids. This wastewater, if not effectively treated, will be a huge threat to human and environmental safety. Herein, we used Fenton to treat Radix Aconiti processing wastewater to explore the effectiveness of Advanced Oxidation Process (AOP) in alkaloids control. The Radix Aconiti processing wastewater was collected as soaking and cooking wastewater whose TOC concentration was 261 and 2950 mg/L, respectively. The effects of initial pH, H2O2, and Fe2+ dosages were investigated and the parameters were optimized by response surface method (RSM). The TOC removal was 66.9 % and 70.3 % for the soaking and cooking wastewater. The concentration of alkaloids was tested by HPLC, and no alkaloid was detected in the effluent of soaking wastewater or cooking wastewater. Our study illustrates that the Fenton can effectively remove toxic substances from Radix Aconiti processing wastewater. The study also proves that AOP has great potential in the treatment of toxic herbal wastewater.