Application of extraction and adsorption to the alkylpyrazine removal from wastewater

Abstract

Application of extraction and adsorption process to the alkylpyrazine removal from wastewater was investigated. The detailed extraction process was studied. It was found that the alkylpyrazine content in the water phase after extraction was decreased to 0.3% or less from about 3.0% (wt.). Extractant was recovered by concentrating the water phase and then the wastewater generated from concentration process was disposed by adsorption treatment in order to further lower the level of alkylpyrazine in wastewater. Adsorption of simulated wastewater containing 2,3-dimethylpyrazine on the different resins was also investigated. Among the resins of various grades used, the XDA-200 had the best properties in decontamination of aqueous 2,3-dimethylpyrazine solutions. The chemical oxygen demand (COD) of authentic wastewater generated from extraction process after adsorption treatment with XDA-200 was less than 1,000 mg/L and its removal percentage was above 90%. It was shown that regeneration of the adsorbent bed could be effectively performed with ethanol. Based on the extraction and adsorption experimental results, more than 98% of COD in the wastewater was removed.

Keywords:

• Alkylpyrazine
• Wastewater treatment
• Extraction
• Adsorption

Acknowledgement

The authors are thankful to the financial support of National Ministry of Science and Technology, which enabled the work in this area.