轉爐石(BOF)為鋼鐵製程之工業副產物且為廉價的吸附劑，粒狀氫氧化鐵(GFH)為商品化吸附劑。本研究以磷酸鹽配製含磷人工水樣，轉爐石取自中國鋼鐵公司，採批次式實驗比較轉爐石與粒狀氫氧化鐵去除水中磷，實驗操作參數包含水洗、pH、BOF與GFH添加量、磷初始濃度及接觸時間等。此外，以能量散佈分析儀(EDS)與熱游離式掃描式電子顯微鏡(SEM)分別測定BOF與GFH之化學成份組成及表面顯微特性。EDS研究結果顯示BOF化學成份組成Ca之重量百分比為12.6%，於水中會溶出鈣且pH大於11，且與水中磷形成Ca-磷酸鹽沉澱物；隨BOF添加量增加而鈣溶出量增加，亦致使磷去除率增加，BOF去除磷主要機制為沉澱。相對地，GFH化學成份組成不含鈣，主要為鐵氧化物佔重量百分比為63%，GFH去除磷主要機制為吸附於表面形成Fe-磷酸鹽化合物；SEM顯微照相亦顯示GFH吸附磷。由於BOF於水中接觸時間30分鐘時鈣溶出達90%，故BOF去除磷於接觸時間30分鐘後無顯著增加，但GFH去除磷則隨接觸時間增加而增加。BOF磷去除量約為GFH之3-4倍，BOF與GFH去除磷之最適pH分別為11與4，隨磷初始濃度增加BOF與GFH磷去除量隨之增加。此外，GFH售價為BOF之120倍。綜合結果，BOF與GFH去除磷機制分別為沉澱與吸附，BOF之磷去除量與經濟性皆優於GFH。 Basic oxygen furnace steel slag (BOF) is an industry by-product from steel manufacture and is a low-cost adsorbent. Granular ferric hydroxide (GFH) is a commercial available adsorbent. This study compares the adsorption removal of phosphate between BOF and GFH. BOF from The China steel company and phosphate-containing synthetic water were used in this study. The operational parameters included water washed, pH, type and dosage of adsorbent (BOF and GFH), initial concentration of phosphate (P), and contact time. All experiments were conducted by the batch. Furthermore, the chemical composition and surface morphology of adsorbents were examined by energy dispersive spectrum (EDS) and scanning electron microscopy (SEM), respectively. The results of chemical composition from EDS tests show that BOF contained 12.6% of Ca (wt%), which released Ca ions from the slag into solution to induce high pH levels to above 11. The released Ca ions could react with P to form the precipitation of Ca-phosphate compounds. The released Ca ions concentration increased with the increasing dosage of BOF and leaded to increase removal of P. In contrast, the chemical composition of GFH did not contain Ca but contained 68% (wt %) of Fe. The removal mechanism of P by GFH was predominant by the formation of Fe- phosphate compounds onto GFH surface. The SEM micrographs show that Fe-phosphate compounds formed on the GFH surface. The optimum pH for the removal of P by BOF and GFH was at 11 and 4, respectively. The phosphate removal capacity (PRC) of BOF was about 3-4times of that of GFH. The removal of P increased with the increasing both dosage of BOF and GFH. Original BOF could remove more than 90% of P, whereas it was about 20% for water washed BOF. The removal of P by BOF did not increase significant as contact time extended more than 30 min because more than 90% of dissolution of Ca ions occurred during the contact time less than 30 min. However, the removal of P by GFH increased with the increasing contact time. Moreover, commercial price of GFH was higher as about 120 times of BOF. Overall, the removal mechanism of P by BOF and GFH was precipitation and adsorption, respectively. Based on the PRC and economic feasibility, BOF is a cost-effective adsorbent than GFH for the removal of P.