淨水廠污泥再利用技術及用途評估之研究

Abstract

我國自來水的供給主要由台灣自來水公司與台北自來水事業處專責，全台每年產生超過15萬公噸淨水污泥，每公噸淨水污泥之再利用代處理費視投標廠商數、淨水污泥之化學組成及淨水場地理位置而介於三百至一千元不等，成為自來水營運主要支出費用。且少數地理位置較偏遠之淨水場，有時會遭遇無廠商願投標代處理之窘境，而使淨水污泥代處理費用更加高漲。 本研究先就國內外自來水淨水污泥產量與處置現況進行文獻資料蒐集與訪查，就淨水污泥回收混凝劑、作為廢水處理藥劑、管溝回填材料、水泥、紅磚、培養土、人造輕質骨材與培養土原料等再利用方式，以技術面、法規面、經濟面、市場行銷等面向進行綜合可行性評估，發現以作為水泥生料、燒結紅磚為具有足夠市場胃納之淨水污泥再利用方式，但自來水公司需給付代處理費予水泥業或磚窯業者代處理費用；而生產培養土即成為技術簡單且具有一定市場之淨水污泥再利用方式，且日本已有相同自資資源化經驗，具有改善自來水公司營運成本功效。 因此本研究以台灣自來水公司新竹給水廠淨水污泥為例，進行探討淨水污泥混合養菇業廢棄太空包木屑與廚餘堆肥共同再利用生產園藝培養土之可行性，並進行育苗試驗、探討相關法規限制，與以新竹給水廠為例進行淨水污泥自資資源化營運經濟效益成本估算，最後證實淨水污泥作為園藝培養土為良好之再利用方式，除產品品質與市售產品相較具有競爭力，且具有經濟效益。因此未來淨水污泥可朝向自資生產培養土進行再利用，除可轉化處置費用為營收，開闢新興財源以改善營運績效，並可解決偏遠地區淨水場淨水污泥處置問題，以達到邁向綠色水廠之最終目標。

More than 150,000 tons water treatment residual is generated each year in the production of drinking water by the Taiwan Water Corporation. The cost for the disposal of such an enormous amount of solid wastes has become a major fraction in the cost for water production. Many successful examples in the reuse of fresh water residual have been reported world-wide, therefore, it is reasonable that the Taiwan Water Corporation should consider the reuse of water sludge into beneficial products themselves. The objective of this study is to evaluate the various technologies in water residual reuse in search for the most feasible mode of operation of sludge reuse for the Taiwan Water Corporation. Among the technologies reviewed, including the manufacturing of construction materials (bricks, cement, light aggregates or control low strength material) and agricultural use (as potting soil or gardening soil), reuse as potting and gardening soil has been discovered most economically competitive. The cost analysis for the manufacturing of potting and gardening soil from water treatment residual indicates that the Taiwan Water Corporation can profit from this means of reuse operation.