以現場實測探討CNS 14431 Q3001油脂截留器性能試驗法之性能判定

ON FIELD MEASUREMENT OF GREASE INTERCEPTOR AGAINST CNS 14431 Q3001 METHOD OF TEST FOR PERFORMANCE OF OIL/GREASE INTERCEPTOR

油脂截留器為下水道系統重要之前處理裝置，我國建築法規定相關建築物需裝置足夠容量的油脂截留器，CNS 14431 Q3001「油脂截留器性能試驗法」為規範截留器性能的標準。經由先前的研究發現油脂截留器的性能試驗，除油脂溫度對截留效率的影響可忽略外，進流水量和溫度、進流水頭和水位及測試用油脂的種類和溫度，對截留效率皆有顯著的影響。本研究長期監測一台安裝於中式自助餐廳的HASS型油脂截留器的污水水質變化結果發現，截留效率及COD去除率(COD removal efficiency)皆隨截留器使用時間而衰減，顯示油脂截留器的清潔與管理機制是否健全，才是油脂截留器性能正常發揮的關鍵。實測結果亦顯示，若當次截留效率太低，將導致實際使用時無法發揮其截留功效。因此在中餐廳高油脂濃度的使用環境中，CNS應採用較嚴苛的性能判定標準如DIN 4040當次截留效率92%以上，以確保所排放的污水水質。實測亦發現，若能施加微量浮除空氣則可進一步提升截留效率及污水水質，此可做為規範修正之參考。

An oil/grease interceptor, a pretreatment of kitchen wastewater, is legislatively required in public sewage systems. CNS 14431 Q3001 “Method of Test for Performance of Oil/Grease Interceptor” is a national standard for the performance of oil/grease interceptors. It has been previously reported that types of testing media, heads of inlet pipes, drainage flow rates and drainage temperatures had profound influence on the interception rate of three well-known grease interceptors. In this study, further field measurements were performed on a grease interceptor installed in a Chinese food cafeteria. It was found that both grease interceptor rate and COD removal efficiency significantly decreased with the increase of the amount treated by an interceptor. It implied that proper maintenance on the interceptor was the key factor in the performance of the interceptor. The performance of an interceptor can be improved with floatation air applied. It can be concluded that CNS 14431 Q3001 should adopt a higher grease interception rate, such as 92% interception rate of DIN 4040, in order to protect sewage systems from becoming highly grease-contented environments.