(北京科技大學(xué) 冶金與生態(tài)工程學(xué)院，北京 100083)
摘 要: 基于已有熱力學(xué)數(shù)據(jù)，對(duì)稀土除磷過(guò)程及沉淀產(chǎn)物的再生過(guò)程分別進(jìn)行了熱力學(xué)計(jì)算，繪制了25 ℃下 -pH圖，為含磷廢水中磷的資源化利用和無(wú)害化處置提供理論支撐。結(jié)果表明：采用稀土處理含磷廢水時(shí)在pH 2.70~8.66范圍內(nèi)沉淀，可生成穩(wěn)定的LaPO4(和CePO4)沉淀，實(shí)現(xiàn)磷的去除；再生過(guò)程pH在14.5~16.0范圍內(nèi)，LaPO4(和CePO4)可轉(zhuǎn)變?yōu)長(zhǎng)a(OH)3(和Ce(OH)3)實(shí)現(xiàn)沉淀劑的再生與磷的回收。采用La(OH)3和Ce(OH)3處理30 mg/L的含磷溶液，磷沉淀率分別為99.72%和96.33%；采用4 mol/L的NaOH溶液分解沉淀產(chǎn)物，反應(yīng)3 h后La(OH)3和Ce(OH)3的再生率分別為30.38%和63.38%。
關(guān)鍵字: 稀土；除磷；熱力學(xué)；廢水處理
（School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing 100083, China）
Abstract:Based on the available thermodynamic data, the thermodynamic calculation of the phosphorus removal process with rare earth and the regeneration process of precipitation products were carried out, respectively. And the -pH diagram at 25 ℃ was drawn to provide theoretical support for the resource utilization and harmless disposal of phosphorus in phosphorus-containing wastewater. The analysis shows that stable LaPO4 (and CePO4) precipitation can be generated within the pH range of 2.70-8.66 to remove phosphorus. During the regeneration process, LaPO4 (and CePO4) can be transformed into La(OH)3 (and Ce(OH)3) in the pH range of 14.5-16.0 to achieve precipitation regeneration and phosphorus recovery. The results show that when La(OH)3 and Ce(OH)3 were used to treat 30mg/L phosphorous solution, the phosphorus precipitation rates are 99.72% and 96.33%, respectively. After 3h reaction, the regeneration rates of La(OH)3 and Ce(OH)3 are 30.38% and 63.38%, respectively.
Key words: rare earth; phosphorus removal; thermodynamics; waste water treatment
