天然有機物於臭氧降解程序中氫氧自由基之生成與消耗及其去除新興污染物之影響

Abstract

臭氧被廣泛應用於去除自來水和廢水中的有機污染物，近幾年來更是運用於降解地表水及地下水中之新興污染物。由於天然有機物(NOM)與臭氧及氫氧自由基的反應相當複雜，所以天然有機物在臭氧處理程序中之影響尚未被闡明。故本研究的目的為：(1)測定天然有機物於臭氧處理程序中起始反應(initiation)、促進反應(promotion)、抑制反應(inhibition)以及與臭氧直接反應之速率常數。(2) 探討pH值及溫度對起始反應、促進反應、抑制反應以及與臭氧直接反應速率常數之影響。(3) 測定及模擬天然有機物於臭氧處理程序中對新興污染物去除之影響。本研究所使用之四種自然水體為：新店溪(新北市)、宜蘭河(宜蘭市)、金沙水庫(金門縣)及台中地下水(台中縣)。結果顯示起始反應、抑制反應及與臭氧的直接反應之速率常數會隨著pH值升高而增加，但促進反應之速率常數則明顯的趨勢。在溫度影響的部分，所有的速率常數皆是隨著溫度的升高而增加。在天然有機物於臭氧處理程序下對新興污染物降解影響的部分，從結果顯示都可利用所測得之速率常數得到良好的預測結果。

Ozonation has been widely used for removing organic contaminants in water treatment. The effect of natural organic matter (NOM) on this process, however, is not well understood due to the complex reactions of NOM with ozone and •OH generated from ozone decomposition. The objectives of this study are to determine the rate constants of NOM from different sources in terms of initiation, promotion, inhibition and direct ozone reactions in the ozonation process and to investigate the influences of NOM on the removal of emerging contaminants. The rate constants of NOM in four natural waters including Hsintien river (New Taipei City), Yilan river (Yilan City), Jinsha reservoir (Kinmen County) and Taichung groundwater (Taichung County) were determined using a recently developed approach that integrates the pseudo first order ozone decomposition kinetics, transient steady state •OH concentration and the Rct concept. The effects of pH value and temperature on the rate constants were also determined. With these rate constants, the influences of NOM on the degradation of three emerging contaminants including ibuprofen, acetylsulfamethoxazole and metoprolol can be fairly well predicted.