Potential of Biological N-Methylpyrrolidone (NMP) Removal in Semiconductor Wastewater under Aerobic Anoxic and Anaerobic Conditions

  • 丘 恬鳳

Student thesis: Master's Thesis

Abstract

The thriving growth of semiconductor industry in this digital era is also accompanied by increase of dangerous wastewater produced containing high concentration of organic compounds including NMP which generally takes part as photoresist stripper solvent Even though previously NMP was considered as benign alternative and has no severe risk to environment but later was found as reproductive and developmental toxin In this study potential of biological NMP removal from semiconductor wastewater using aerobic anoxic and anaerobic conditions was evaluated Laboratory scale of aerobic MBR system was developed to resemble real wastewater treatment plant condition Additionally several batch assays were also conducted to evaluate behaviors of NMP removal process in each conditions with different initial concentrations Stable and effective removal of NMP as high as 99% was successfully achieved using aerobic MBR as well as in aerobic batch experiment Moreover this removal process of NMP apparently could be reach up to mineralization process Higher tolerance to higher NMP loading was also shown in this condition compared to others Nevertheless great potential of NMP removal was also shown in anoxic condition especially in low concentration and faster NMP degradation rate for each subsequent runs could be achieved On the other hand in this study biological NMP removal could not be effectively achieved in anaerobic condition Despite of the effectiveness some limitations shown in each aerobic and anoxic conditions In aerobic presence of NMP inhibited nitrification process (total inhibition possibly occurred in high NMP loading) which therefore followed by ammonia accumulation Meanwhile in anoxic conditions some intermediates that could not be further biologically removed might remained in system which indicated different NMP degradation pathway between aerobic and anoxic condition possibly occurred
Date of Award2018 Aug 22
Original languageEnglish
SupervisorLiang-Ming Whang (Supervisor)

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