Ultrasonication pretreatment of real-field pulping wastewater from bagasse-based paper mill

Abstract

In this study an attempt has been made to evaluate the feasibility of utilizing ultrasonication as pretreatment process to treat pulping wastewater. Bio-electrochemical treatment and microalgal treatment have been used as secondary treatment process. Ultrasonication was performed in bath type sonicator at 60 kHz for various time intervals of 15, 30, 45 and 60 min. There were no significant changes in pH, TDS and COD of pulping wastewater after ultrasonication. The bio-electrochemical treatment of pretreated wastewater did not show significant improvement in treatment efficiency and color removal. Rather the MFC operating with pretreated wastewater showed poor electrochemical performance. Microalgae consortia collected from lily pond in the institute could decolorize the ultrasonically pretreated wastewater, but color of raw wastewater could not be decolorized by micro algal consortia. Ultrasonication could have modified the compounds in pulping wastewater, making them more accessible to microalgal metabolism.