加壓浮除法於養牛廢水實場處理效率之探討

Investigation of the effect of dissolved air flotation on dairy wastewater treatment

鄭閔謙(Min-Chien Cheng) ； 蘇天明(Tein-Ming Su) ； 蕭宗法(Tzong-Faa Shiao) ； 蕭庭訓(Ting-Hsun Hsiao) ； 程梅萍(Mei-Ping Cheng)

《畜產研究》 50卷2期 (2017/06) Pp. 110-115

摘要

乳牛糞便與廢水中含大量懸浮不可溶之纖維質，常造成廢水處理上之困難。因此，本研究為評估加壓浮除法對養牛廢水處理效率之影響。試驗一將加壓浮除系統分別設置於三段式廢水處理系統之固液分離單元後、厭氣處理單元後及好氣處理單元後，測定該系統對各階段處理水化學需氧量（COD）及懸浮固體物（SS）之去除效率。試驗二將加壓浮除系統設置於固液分離單元後，分別將浮除前與浮除後之養牛廢水注入至厭氧處理模型槽，再以溢流方式至好氣處理模型槽，連續60日。測定浮除前、後與比較兩者於厭氣處理後及好氣處理後之水中COD與SS之差異。試驗一結果顯示，加壓浮除法對固液分離後之COD與SS去除效率最佳，分別為56.2與50.8%；對厭氣處理後之去除率分別為4.28與8.80%；對好氣後之養牛廢水中之去除率分別為4.63與13.7%。試驗二結果顯示，固液分離後之養牛廢水經加壓浮除後，可去除廢水中49.8與55.8%之COD與SS，此處理水質經厭氣處理後，其處理水中之COD與SS濃度，分別比未經浮除者低51.5與83.2%。處理水再經好氣處理後之放流水中COD與SS濃度分別比未經浮除者低41.0與62.7%。雖然如此，好氣處理後之化學需氧量尚不能符合放流水標準。綜上所述，加壓浮除法可以大幅降低固液分離後之養牛廢水中COD與SS，並對其後續處理後之放流水質有大幅度改善的效果。

關鍵字

乳牛 ； 廢水處理 ； 加壓浮除

並列摘要

The wastewater treatment system of dairy cattle in Taiwan is usually a sequential process from solid-liquid separation (ASL), anaerobic digestion (AAD), aerobic treatment (AOT) and final precipitation to discharge. Dairy cattle are herbivorous animal, so there is large amount of suspended fiber in its manure and wastewater. Some fiber cannot be removed with the solid-liquid separator and precipitated in wastewater treatment system. Therefore, the purpose of this study was to investigate the effect of applying a dissolved air flotation system (DAF) on the efficiency of dairy cattle wastewater treatment system by on-site experiments with continuous flow. The DAF was set up behind the ASL, AAD and AOT processes, respectively, then those of move efficiency of DAF for different stage of dairy cattle wastewater were determined in trial I. The DAF was set up after ASL process, then the COD and SS of influents and effluents of DAF, AAD and AOT were analyzed - in trial II and the data were compared to those of treatments without DAF. The results of trial I revealed that the removal efficiency of SS and COD on ASL was 50.8 and 56.2%, respectively. The removal efficiency of SS and COD on AAD was 8.80 and 4.28%, respectively. The removal efficiency of SS and COD on AOT was 13.7 and 4.63%, respectively. In trial II revealed that the removal efficiency of COD and SS of DAF were 49.8 and 55.8%, respectively. The COD and SS concentrations of AAD effluent with DAF were lower than those without DAF at 51.5 and 83.2%, respectively. The COD and SS concentrations of AOT effluent with DAF were lower than those of without DAF at 41.0 and 62.7%, respectively. In conclusion, DAF could be applied to reduce the COD and SS of dairy wastewater after solid-liquid separation, so the discharge water quality could be improved by the following treatment.

並列關鍵字

Dairy cattle ； Wastewater treatment ； Dissolved air flotation