Developing a reaction column to treat chlorinated phenols (CPs) in liquid

[[abstract]]由於農業用藥的使用及木材工業之氯酚廢水的排放，造成土壤及地下水之污染，對環境及生物皆有相當的危害，氯酚類具有致癌性及基因突變性，因此如何有效的處理此類污染是一個值得深入研究的課題，因此本研究開發一種氧化降解反應管，適用於現地地下水處理的技術，並進而評估處理之效率及方法之可行性。本研究以H2O2 + EDTA-Fe之化學氧化法為基礎，以不同材料性質之擔體將催化劑EDTA-Fe固定於顆粒內，並填充於反應管中，之後通過已添加H2O2的氯酚污染水並探討去除效果，本研究目的包括：（1）探討液相低氯酚與五氯酚之氧化降解效率，（2）測試並確定最適化之EDTA-Fe固定方法，及（3）決定連續式處理單元之最適操作策略。 液相單、雙氯酚與五氯酚之氧化降實驗結果顯示：反應組氯酚污染物在氧化反應60 mins後完全去除，證明H2O2 + EDTA-Fe 對於處理液相氯酚是可行的。比較三種顆粒24小時Fe脫附行為顯示：幾丁聚醣顆粒脫附百分比4 94%，黏土顆粒脫附百分比為7 79%，洋菜膠顆粒脫附百分比則為6 86%，固定化效果以幾丁聚醣最佳；比較顆粒氯酚批次處理效率，三種顆粒對於處理液相氯酚實驗，在反應8小時後，低氯酚皆能降解達90%以上，五氯酚則約達70%以上，證明三種顆粒皆能處理氯酚污染水；比較連續式系統處理效能之結果顯示，4小時總降解率之大小為：幾丁聚醣（82 86%）>黏土（79 42%）>洋菜膠（66 35%），總結以上，最佳固定化顆粒為幾丁聚醣顆粒。本研究之幾丁聚醣連續式系統的最適化操作參數為：H2O2氧化劑濃度—2%、泵浦進流量—0 674 ml、系統含鐵量—704 51 mg、系統失效時間24 hrs。本研究之連續式反應系統限於設計考量而導致實驗有所侷限，因此將系統作更完善的改良，如：擴大管徑、加強顆粒固定化性能等，以提升系統整體效能。[[abstract]]Discharge of the chlorinated phenol (CP) wastewater from the chemical manufacturers and possibly from the agriculture and timber industries causes soil and groundwater contamination and risks the environment and ecology as well CPs are carcigenic and mutagenic agents An effective mean of removing them from the liquid is deemed important From some not-yet-published soil treatment results the EDTA-Fe plus peroxide demonstrated its ability in treating lower chlorinated phenols in great efficiency Thus in this study we were looking for a well design reactive column filled with EDTA-Fe coated media to treat the CPs contaminated wastewater continuously The main objectives of this study included: (1) to explore degradation efficiencies of the lower chlorinated phenol and pentachlorophenol in liquid (2) to determine the best applicable mean in fixing EDTA-Fe on various supporting materials and (3) to conclude the best strategy in column operation The results showed that 100% CPs were removed with 60 minutes in a well mix batch system which proofed the treatment of liquid CPs by the proposed oxidation mean Three EDTA-coated particles were made including the chitosan the clay and the gel particles with the 24-hour desorption rate of EDTA-Fe at 4 94 7 79 and 6 86% respectively The chitosan particle was obvious the better choice in term of catalyst binding Three particles showed their degradation efficiency of lower chlorinated phenol degradation and PCP at 90 and 70 plus per cents respectively During a 4-hour column treatment test the percent of total CPs degradation by the chitosan clay and gel particles were 82 86 79 42 and 66 35 respectively Based on the above results we concluded that chitosan which adsorbed more EDTA-Fe and degraded more CPs in column test was the best adsorbent of the three media tested Further test of chitosan particle in column run in various flowrates and peroxide concentration in liquid The results showed that when peroxide concentration at 2% and flowrate at 0 674 mL the treatment efficiency was highest The column reached its break through point in about 24 hour