- 學位論文
利用薄膜生物反應器(MBR)處理鋼鐵冷軋廢水之研究與工程應用
Treatability Study and Engineering Planning of MBR (Membrane Bioreactor) in Treating the Cold-Rolled Steel Wastewater
摘要
鋼鐵之冷軋製程係將熱軋後之鋼捲進行酸洗除銹，並塗上軋延油進行後續冷軋程序，再以鹼液來清洗殘存於鋼捲上之油劑，因使用到大量的水源和酸鹼劑來作清洗，相對也產出等量的製程廢水。其廢水包括含油、含鹼及含酸等三種，含酸廢水僅需調整pH值及去除水中鐵銹即可排放；但含油及含鹼廢水中因含有礦物油、界面活性劑及乳化劑等，其水中的COD約為2,000~3,000 mg/L，傳統處理方式為先經除油、破乳及浮除等處理方式，然後與含酸廢水進行混合，最後再經化學混凝處理後排放。本研究有別於前述處理方式，係以薄膜生物反應器(Membrane Bioreactor ,MBR ) 來處理廢水中的污染物質，並以含油及含鹼廢水作為研究目標。製鋼鐵廠取經除油、浮除及化學混凝處理後之廢水來進行MBR模廠之測試，模廠操作採連續進出流方式。經由測試後，系統在10 hrs的水力停留時間(HRT)下，出流水質可達COD< 80 mg/L、SS< 1 mg/L及油脂<8 mg/L之效果，其COD及油脂去除率可達93%以上，可知MBR程序能有效去除該廢水中的污染物質，並可降低排放廢水於對水體環境之衝擊。同時，將模廠測試所得之結果進行工程規劃，以處理水量1,500 CMD作評估設計，經由估算後，系統之初設成本(含土木工、機械設備、儀控及管線等工程)為2,795萬元，而其每噸廢水處理之操作費用(含電力、藥品、人事、耗材及廢棄污泥處理等項目)則需9.96元。
並列摘要
The hot rolled steel will be pickled. Pickling is the process used to remove rust from the surface of steel. Then, the steel which coated a rolling oil will be rolled. By alkali washing, it can remove the oil of steel surfaces. It needs much water, acid and alkaline solutions to clear the steel surfaces. Therefore, there will be a lot of process wastewater. The wastewater can be divided into oil, alkali and acid. Acid wastewater can drain after adjusting the pH and removing the rust. Because of containing mineral oils, surface-active agent and emulsifier, the COD of oil and alkali wastewater is 2,000~3,000 mg/L. It must be treated with physico-chemical treatment process (such as degreasing, emulsion breaking and flotation). Then, it will be mixed with acid wastewater and treated with chemical coagulation. This study is different from the aforementioned approach. Using Membrane Bioreactor (MBR) to treat oil and alkali wastewater which treated with chemical coagulation. It will use MBR pilot to be continuity test. After the test, the pilot has good removal efficiency of 93% of COD and grease. In hydraulic residence time of 8 hours, effluent of COD and grease is less 80 mg/L and 8 mg/L. At the same time, the results of MBR pilot will be planned on 1500 CMD of wastewater treatment plant. Estimating the MBR system set-up costs (including civil engineering, mechanical equipment, instrumentation and pipeline and other projects) is 2,795 million. The operating cost (including electricity, drugs, personnel, supplies and waste sludge treatment projects) per ton of wastewater treatment need to 9.96 dollars.