| 摘要: | 對磷研究重點已由考慮水中總磷量或正磷酸鹽含量，改聚焦於底泥中可被微細植物吸收應用之溶解反應性磷量(SRP, Soluble reactive phosphorus)，溶解反應性磷量包括可交換態磷、與鐵氧化物鍵結態磷及有機磷。台灣河川底泥整治工程已為重要環境議題，河川底泥環境 改變(如底泥溶氧量、pH值、氧化還原電位及溫度)，將造成底泥顆粒鍵結態磷轉移或滲出水溶相磷而影響週遭環境。本研究採台灣南部遭受嚴重工業、農業及家庭廢水污染三條河川(二仁溪、三爺宮溪、及鹽水溪)底泥，於實驗室進行批次試驗，探討pH值、氧化還原電位、溫度及微生物活性影響底泥各種鍵結態磷轉移或釋出至水體之總磷及正磷酸鹽量。實驗數據顯示高氧化電位及高還原電位，有助底泥中總磷及正磷酸鹽釋出到水相，氧化電位接近零釋出能力變差；底泥水溶液含氧量越高，正磷酸鹽越易被好氧性微生物消耗，導致正磷酸鹽與總磷比值越小；底泥中自生性磷灰石+碳酸鈣鍵結磷+生物性磷灰石(Authigenic apatite plus CaCO3-bound P plus biogenic apatite, F3)鍵結態磷量則隨pH值增加而減少；添加葡萄糖增加微生物活性，厭氧態比好氧態培養更益增加底泥顆粒總磷釋出量；隨反應天數增加，母岩碎屑中磷灰石+其他無機磷(Detrital apatite plus other inorganic P, F4)鍵結態磷量減少，F3鍵結態磷量增加，而可交換態磷(Exchangeable or loosely sorbed P, F1)、與鐵氧化物鍵結態磷(Fe-bound P, F2)及有機態磷(Organic P, F5)總和之溶解反應性磷量(SRP)會增加；SRP亦隨底泥之強氧化態、強還原態及高pH值環境存在而增加。
The focus of phosphorus (P) study has changed from total phosphorus and ortho-phosphate (in water) to soluble reactive phosphorus (SRP) in river sediments fractionation, which could be absorped by phytoplankton, including exchangeable or loosely sorbed P (F1), iron bound P (F2) and organic P (F5). The remediation of contaminated river sediments has become important issues in Taiwan. Environmental factors, such as dissolved oxygen, pH, oxidation reduction potential (ORP) and temperature, would affect the transformation of P fractionation in sediment particles and the liberation of phosphate etc. into water. Sediments in Erren, Sanyegong and Yenshui rivers were seriously contaminated with the discharges of domestic sewage, agricultural wastes and industrial effuents in southern Taiwan area. The sediment particles were studied with different environmental factors in batch experiment. Results showed that the higher levels of oxidation or reduction potential induced more release of total phosphorus and ortho-phosphate into water. The aerobic microorganism used ortho-phosphate and induced lower ratio of ortho- phosphate versus total phosphorus at sediment suspension filled with higher oxygen concentration. Authigenic apatite plus carbonate fluorapatite phosphorus plus biogenic apatite (F3) fraction of sediment particles decreased versus increase of pH values. The microorganism activities increased with addition of glucose into aerobic and anaerobic sediment suspension. However, the released amount of total P under anaerobic condition was better than at aerobic condition. When the sediment keep at some environmental factors after 15 days, detrital apatite plus other inorganic P (F4) decreased, F3 fractionated P increased, as well as the sum of F1, F2 and F5 (i.e. SRP) increased. The ratios of SRP increased with higher oxidation potential, higher reduction potential, higher pH value, and addition of formalin in sediments. |
