| 摘要: | 近年在河川污染整治針對於氨氮達成率偏低之河川，作為改善重點對象。因此，為改善河川污染情形，在污水下水道用戶接管前，多數以現地工法淨化河川水體水質，以期減低河川污染情形，改善河川水質。然而，機關雖可爭取相關補助經費建置，但後續操作維運經費需由自行負擔。於水質淨化設施建設完工後，各縣市市府需編列預算維持運轉。因此，針對已完工運轉水質淨化設施之設置成效進行評估與效益分析，可以作未來各現地處理設施營運之操作之參考。
因此，本研究以新勢礫間水質淨化設施作為對象，其每日最大可處理 3 萬噸生活污水，為目前處理水量最大之場址，主要處理桃園市主要河川老街溪及平鎮區宋屋及新勢地區生活污水。設施自102年起完工試運轉，截至109年該設施已運作達8年，除建造成本、電費外，桃園市政府也投入許多資源委外操作維護以維持設施之正常運轉。
透過實場各年度操作水質資料進行彙整分析，探討礫間接觸曝氣氧化工法對河川質水質改善效益，及實場建置成本與操作營運成本進行經濟效益分析，並與桃園市已完工運轉操作水質淨化設施相關資訊進行研究，提出結論與建議，作為後續在桃園市其他案場設計、維護及經費編例之參考。
經統計103年至109年資料，新勢礫間水質淨化設施水質改善成效，以年平均去除率來看，109年生化需氧量去除效率最高可達88.3%，生化需氧量7年平均為80.6%、107年懸浮固體最高可達98.7%，懸浮固體7年平均去除率為86.7%、105年氨氮最高可達97.6%，氨氮7年平均去除率為(91.1%)，各年度去除效率平均皆可達設計目標 70% 以上。其中以氨氮之去除效率最佳，處理後之水質更可低於1 mg/L，因此，透過良好操作，可維持設施之處理成效，而其氨氮處理效率可達90%以上，亦可作為政府後續推動氨氮去除之參考工法。另本研究場址之處理效率另與桃園市四方林礫間及桃園市大檜溪橋礫間比較分析，以109年度水質為基準，新勢礫間之效率最佳，次之為大檜溪橋礫間，四方林礫間處理效率稍低，但各場皆可達設計目標。
本研究場址之設置效益評估，建造成本為6,607元/CMD，平均水質處理成本為0.96元/CMD。自106年起透過減少鼓風機開啟台數，由4台常開減至2台後，每年用電量從125萬度下降至88萬度，同時可達目標去除率。
;In recent years, the governments focus on river pollution remediation, especially targets on rivers which did not reached the objective of removal rate on ammonia nitrogen. Therefore, we mostly adopt local purification system to the river before installing sewerage system to the users, expecting to decrease the situation of river polluting, and also improving water quality. However, Governments Agency could obtain financial subsidy for the facility constructing, the maintenance of the facility would have to be covered by Governments Agency themselves. Governments certainly need to budget to keep the maintenance after the completion of facility. As a result, the benefit assessment and analysis on completed facilities could be referred to the future planning on facilities operation.
Therefore, we took Xinshi Water Purification Facility as a research object, which could handle maximum 30,000 tone of sewage disposal per day and is also the biggest purification in our nation. Xinshi Water Purification Facility is mainly disposal of sewage from Laojei Creek in Taoyuan City, Songwu Village in Pingzhen District and Xinshi area. The Xinshi Water Purification Facility was completed in ROC 102. It has been operating for eight years by far. The Taoyuan City Government has distributed to outsource from the beginning, keeping the maintenance of the facility, including construction costs, electricity fees etc.
To explore the benefits of using “Gravel Contact Oxidation Purification” in creek water improvement, water quality data are collected each year to be analyzed, and the cost of facility constructing and operating are analyzed for the economic benefit, do research on several operating water purification facilities located in Taoyuan City to able to get the conclusions and make suggestions for follow-up facilities designing, maintenance, budgeting etc., in Taoyuan City.
According to Xinshi Gravel Water Purification Facility collected statistics from ROC 103 to ROC 109, it shows significant improvement on water quality. In these years, the BOD(Biochemical Oxygen Demand) removal rates is 80.6% on average, highest rate of 88.3% in ROC 109, the SS(Suspended Solids) removal rate is 86.7% on average, highest rate of 98.7% in ROC 107, the average of ammonia nitrogen removal rate is 91.1%, the design objective of removal rates reach above 70% each year. Among of them, the ammonia nitrogen removal is the most efficient, the density of ammonia nitrogen could even get lower than 1 mg/L, and the processing efficiency could reach above 90% with well operation, so they are certainly referable methods to the government for facilities promotion. Furthermore, Comparing to SifangLin Gravel Water Purification Facility and Dakuaisi Bridge Gravel Water Purification Facility, Xinshi Gravel Water Purification Facility operates the most efficient based on water quality inspection in ROC 109, Dakuaisi Bridge’s is the second-best, SifangLin’s is least comparable, but nonetheless all reached the design objective.
The benefit assessment of the researching fields’ setting: Construction Costs: 6,607 NTD/ CMD, the average of Water Quality: 0.96 NTD/ CMD. Since decreasing the operation of blowers in ROC 106, from 4 units to 2 units, the Annual Power Consumption sharply declined to 88 GWh from 125 GWh. Meanwhile, objective removal rate is reachable. |
