本研究以有機磷農藥之福瑞松 (Phorate)及托福松(Terbufos)為目標物，研究目的為（1）探討Fenton混凝去除福瑞松與托福松、及（2）比較鐵鹽混凝、Fenton及Fenton-like混凝去除福瑞松與托福松。所有實驗採瓶杯試驗，人工原水含有機磷農藥濃度為100 μg/L，操作參數為pH、鐵鹽種類、過氧化氫(H2O2)加藥量及腐植酸有機物共存，鐵鹽加藥量以Fe2+或Fe3+計之。 研究結果顯示鐵鹽(Fe2+/Fe3+)混凝去除福瑞松及托福松之最適pH為 4.0，主要去除機制為吸附與絆除沉澱，Fe3+混凝去除福瑞松及托福松效果優於Fe2+混凝。此外，Fe2+、Fe3+混凝或H2O2氧化對福瑞松及托福松去除率皆低於55%。Fenton及Fenton-like混凝氧化福瑞松及托福松之最適pH值為4.0，福瑞松及托福松殘留率皆低於5%以下。比較五種程序於pH=4.0時，福瑞松及托福松去除率大小依序為Fenton>Fenton-like>Fe3+>Fe2+>H2O2。 原水中含天然有機物腐植酸共存，濃度在1.0~5.0 mg/L as NPDOC，因腐植酸與福瑞松及托福松競爭混凝劑吸附，使Fe2+/Fe3+混凝去除福瑞松之殘留率增加且達到90%，故腐植酸共存會影響Fe2+/Fe3+混凝去除福瑞松及托福松。相對地，腐植酸共存時，Fenton及Fenton-like混凝對福瑞松及托福松之去除率僅減少2~10%，顯示腐植酸共存對Fenton及Fenton-like混凝去除福瑞松及托福松無顯著影響，故H2O2可提高Fe2+/Fe3+混凝去除福瑞松及托福松，且不受腐植酸共存影響。 Phorate and terbufos are organophosphorus pesticides. Using the synthetic raw waters containing 100 μg/L of phorate or terbufos, the purposes of this study are (1) to investigate the removals of phorate and terbufos by the Fenton coagulation process, and (2) to compare the removals of phorate and terbufos among iron salts (Fe2+/Fe3+) coagulation, the Fenton((Fe2+/H2O2) coagulation and the Fenton-like (Fe3+/H2O2) coagulation processes. The operational variables studied include pH, type of iron salts, hydrogen peroxide (H2O2) dosage and coexisting organics of humic acid. All experiments are conducted by the Jar test. The results show that the optimum pH for the removal of phorate and terbufos was at 4.0. The mechanism for the removal of phorate and terbufos was mainly by adsorption and precipitation. The removal of phorate and terbufos by ferric coagulation was better than that by ferrous coagulation. Furthermore, the removals of both phorate and terbufos by peroxidation and iron salts coagulation were less than 55%. The optimum pH for the removal of phorate and terbufos by the Fenton coagulation and Fenton-like coagulation was at 4.0 and the residuals of phorate and terbufos were less than 5%. The removal of phorate and terbufos was mainly by hydroxyl radical oxidation. Comparing the removals of phorate and terbufos among different processes at pH 4, the sequence of the removals of phorate and terbufos were Fenton coagulation>Fenton-like coagulation>ferric coagulation>Ferrous coagulation>peroxidation. The increase of phorate removal was not affected significantly by increasing H2O2 dosage. As the synthetic raw water contained coexisting organics of humic acid of 1.0~5.0 mg/L as NPDOC, the residuals of phorate and terbufos increased and reached to 90% for ferric coagulation and ferrous coagulation processes. This was due to the competition of adsorption sites on coagulants between humic acid and organophosphorus pesticides. Therefore, coexisting of organics of humic acid affected the removals of phorate and terbufos by iron salts coagulation. In contract, in the presence of humic acid, the removals of phorate and terbufos decreased slightly 2-10%.It implied that the effect of the removals of phorate and terbufos on coexisting humic acid was not significant for the Fenton coagulation and Fenton-like coagulation. It is concluded that H2O2 could enhance the phorate removal by iron salts coagulation and was less affected by coexisting of humic acid.
