廢水中的鈣離子
(中南大學(xué) 冶金科學(xué)與工程學(xué)院，長(zhǎng)沙 410083)
摘 要: 采用剩余污泥與人造沸石復(fù)合體系去除廢水中的Ca2+，考察了各因素對(duì)Ca2+去除的影響。結(jié)果表明：沸石與廢水的固液比是影響Ca2+去除的最關(guān)鍵因素，溫度和pH值的影響較大，而反應(yīng)時(shí)間在最初10 min內(nèi)影響顯著，之后則影響較小；在25 ℃，初始pH值8.04條件下，反應(yīng)1 h，Ca2+的去除率隨著固液比的增加而增大，初始Ca2+的質(zhì)量濃度為801.60 mg/L時(shí)，保持沸石與廢水固液比為3׃100，Ca2+的去除率達(dá)到80.38%，剩余Ca2+僅為157.31 mg/L；升高溫度對(duì)Ca2+去除有促進(jìn)作用，Ca2+的去除率從20 ℃時(shí)的77.30%增大到45 ℃時(shí)的90.71%；Ca2+去除在最初的50 min內(nèi)吸附達(dá)到平衡。人造沸石的紅外光譜圖表明脫鈣過(guò)程主要是化學(xué)吸附。
關(guān)鍵字: 剩余污泥；人造沸石；鈣離子；廢水凈化
sludge and artificial zeolites
SHU Yu-de, ZHOU Min, FANG Yan, WANG Pu, CHANG Hao
（School of Metallurgical Science and Engineering, Central South University, Changsha 410083, China）
Abstract: Removal of calcium from wastewater was carried out using waste activated sludge and artificial zeolites. The effects of parameters such as pH, temperature, reaction time and sorption duration on removal rate of Ca2+ were studied. The results show that solid-to-liquid ratio is the most important factor on the removal of Ca2+, pH and temperature have obvious influences on the process, and reaction time has little effect on removal rate of Ca2+ after reacting for 10 min. The removal rate of Ca2+ increases with increasing solid-to-liquid ratio under conditions of 25 ℃, initial pH 8.04, reacting for 1 h. 80.38% of the initial Ca2+ content (solution containing 801.60 mg/L of Ca2+) is removed under condition of solid-to-liquid ratio of 3׃100, and terminal concentration of Ca2+ of 157.31 mg/L. The increase of temperature is advantageous to the removal of Ca2+, the removal rate of Ca2+ rises from 77.30% to 90.71% with temperature enhancing from 20 ℃ to 45 ℃. The removal of Ca2+ is finished in 50 min. According to the IR spectrum of artificial zeolite, chemical biosorption takes main effect on the removal of Ca2+.
Key words: waste activated sludge; artificial zeolites; Ca2+; wastewater purify
