發(fā)布時(shí)間：2018-07-23 14:38

【摘要】：本文在污酸蒸發(fā)濃縮基礎(chǔ)之上,對(duì)蒸發(fā)濃縮過(guò)程中收集的酸性含氟、氯離子冷凝液的凈化工藝進(jìn)行了實(shí)驗(yàn)研究。通過(guò)對(duì)國(guó)內(nèi)外含氟、氯廢水處理工藝的分析比較,研究了采用氫氧化鈣+偏鋁酸鈉二級(jí)沉淀和離子交換樹(shù)脂吸附深度處理高氟高氯酸性廢水的組合工藝。主要研究?jī)?nèi)容和結(jié)論如下:實(shí)驗(yàn)首先研究了氫氧化鈣+偏鋁酸鈉處理高氟高氯酸性廢水過(guò)程中各個(gè)因素對(duì)氟、氯離子去除效果的影響。結(jié)果表明:一級(jí)沉淀過(guò)程中,按鈣∶氟摩爾比為1∶2,鈣:鋁:氯摩爾比為2∶1∶1投加氫氧化鈣和偏鋁酸鈉,控制反應(yīng)溫度25℃,p H在12.5左右,攪拌轉(zhuǎn)速400 r/min,反應(yīng)時(shí)間80 min,PAM投加量為20 mg/L。在該條件時(shí),廢水中氟離子濃度從6300 mg/L下降至19.3 mg/L,氯離子濃度從1200 mg/L下降至597 mg/L。二級(jí)沉淀過(guò)程的最佳條件為:按鈣∶鋁∶氯摩爾比為6∶3∶1投加氫氧化鈣和偏鋁酸鈉,反應(yīng)溫度在25℃,攪拌速度為300 r/min,p H在12.5左右反應(yīng)60 min,PAM投加量為20 mg/L。經(jīng)二級(jí)沉淀處理后,上清液中氯離子下降到191 mg/L,氟離子下降到5 mg/L。然后實(shí)驗(yàn)考察了201×7陰離子交換樹(shù)脂對(duì)二級(jí)沉淀后的低濃度氟、氯廢水的處理效果及離子交換過(guò)程的作用機(jī)理。確定了靜態(tài)實(shí)驗(yàn)的最佳條件為樹(shù)脂投加量為2.5 g,p H在11以下,控制溫度25℃,樹(shù)脂吸附反應(yīng)30 min即可達(dá)到平衡,在此條件下可使氟、氯離子去除率分別達(dá)到72%和90.3%。影響樹(shù)脂離子交換吸附氟、氯離子的因素的先后順序?yàn)?樹(shù)脂投加量㧐反應(yīng)時(shí)間㧐反應(yīng)溫度。201×7樹(shù)脂去除氟、氯離子的作用機(jī)理以離子交換為主;201×7樹(shù)脂對(duì)氟、氯離子的吸附過(guò)程較符合Langmuir等溫吸附模型。動(dòng)力學(xué)研究表明,201×7樹(shù)脂對(duì)氟、氯離子的吸附反應(yīng)可以用二級(jí)動(dòng)力學(xué)模型解釋,離子交換吸附過(guò)程主要是吸附反應(yīng)階段控制。動(dòng)態(tài)吸附實(shí)驗(yàn)時(shí)進(jìn)水流速控制在28 m L/min較為合適,高徑比控制在6.25左右為宜。動(dòng)態(tài)解析實(shí)驗(yàn)以濃度為1mol/L的Na OH溶液為解吸劑,流速在5 m L/min時(shí)再生效果最佳。
[Abstract]:Based on the evaporation and concentration of waste acid, the purification process of acidic fluorine and chloride condensate collected in the process of evaporation and concentration was studied experimentally in this paper. Based on the analysis and comparison of the treatment process of wastewater containing fluorine and chlorine at home and abroad, the combined process of advanced treatment of perchloric acid wastewater with calcium hydroxide and sodium metaluminate and ion exchange resin adsorption was studied. The main contents and conclusions are as follows: firstly, the effects of various factors on the removal of fluoride and chlorine ions in the treatment of perchloric acid wastewater with calcium hydroxide were studied. The results showed that calcium hydroxide and sodium aluminate were added at 2:1:1 according to the molar ratio of calcium to fluorine at 1: 2, and the reaction temperature was about 12.5 at 25 鈩，

本文編號(hào)：2139719