電鍍業為傳統產業，多屬小規模加工廠，所使用之污染防制方法皆為傳統處理方法，面對日益嚴苛的環保法規，受限於空間有限，多僅能以改良傳統處理程序或提升其效能加以因應。本研究以台南某電鍍廠之電鍍廢水進行試驗，該股廢水為廠內之混合廢水，本研究以同一採樣批次之廢水進行試驗，試驗前分析其基本水質為pH 3，導電度10.54 ms/cm，同時含有多種重金屬，包括鐵、鉻、鎳、鋅、鋁，化學需氧量(COD)為745 mg/L。本研究探討以傳統化學沉澱法搭配聚氯化鋁(PACl)與氯化鐵兩種混凝劑，對此股廢水中重金屬與COD之去除效果。其研究結果發現以化學沉澱搭配化學混凝去除電鍍廢水中之重金屬與COD，以氯化鐵相較於PACl，去除效果更為優異。廢水之重金屬與COD含量添加劑量增加而有所遞減，其結果表示化學混凝具有去除重金屬與少部分COD之效果。而氯化鐵之添加有助於Cr及Al之處除。無論是氯化鐵或PACl混凝，皆以Ni與Zn較難達到放流水標準。對於殘餘重金屬與COD，可考量活性碳或其他吸附劑之投加，提升去除率。建議未來可針對以Fenton法作前處理後，再進行化學沉澱與混凝操作，作進一步的研究探討。 Electrical plating is one of the typical small-scale traditional manufactory industries. Wastewater treatment methods in electrical plating factories are traditional method of chemical precipitation. Facing the serious environmental protection law, limitation of space makes the factories only can do modification of the treatment process or try to upgrade the treatment efficiency.This research focuses a wastewater sample from one electrical plating factory where the wastewater treatment system contains wastewater collecting drain from different units after the production process. The wastewater was collated and performed all the analyzing in this research with the same batch of sample. The water quality of the wastewater was analyzed and revealed to be pH 3, conductivity 10.54 mS/cm, COD 745 mg/L, and containing several kinds of metal ions, such as Fe, Cr, Ni, Zn, and Al. This study has discussed the removal of heavy metal and the reducing of chemical oxygen demand using precipitation and coagulation using in plating wastewater treatment.The results indicated that the ferric chloride coagulation has better performance in metal and COD reduction than PACl. The removal rate of metals and COD increases with increasing pH and coagulant dose. Ferric chloride coagulation is helpful for Cr and Al removal. Ni and Zn are difficult to be removed in meeting the wastewater effluent standards. It suggested that removal of residual metal ions and COD could be advanced by adding active carbon process. Further research could focus on the application of Fenton in pretreatment before chemical precipitation and coagulation.
