發(fā)布時間：2018-07-23 14:38

【摘要】：本文在污酸蒸發(fā)濃縮基礎之上,對蒸發(fā)濃縮過程中收集的酸性含氟、氯離子冷凝液的凈化工藝進行了實驗研究。通過對國內(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+偏鋁酸鈉二級沉淀和離子交換樹脂吸附深度處理高氟高氯酸性廢水的組合工藝。主要研究內(nèi)容和結論如下:實驗首先研究了氫氧化鈣+偏鋁酸鈉處理高氟高氯酸性廢水過程中各個因素對氟、氯離子去除效果的影響。結果表明:一級沉淀過程中,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,控制反應溫度25℃,p H在12.5左右,攪拌轉速400 r/min,反應時間80 min,PAM投加量為20 mg/L。在該條件時,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。二級沉淀過程的最佳條件為:按鈣∶鋁∶氯摩爾比為6∶3∶1投加氫氧化鈣和偏鋁酸鈉,反應溫度在25℃,攪拌速度為300 r/min,p H在12.5左右反應60 min,PAM投加量為20 mg/L。經(jīng)二級沉淀處理后,上清液中氯離子下降到191 mg/L,氟離子下降到5 mg/L。然后實驗考察了201×7陰離子交換樹脂對二級沉淀后的低濃度氟、氯廢水的處理效果及離子交換過程的作用機理。確定了靜態(tài)實驗的最佳條件為樹脂投加量為2.5 g,p H在11以下,控制溫度25℃,樹脂吸附反應30 min即可達到平衡,在此條件下可使氟、氯離子去除率分別達到72%和90.3%。影響樹脂離子交換吸附氟、氯離子的因素的先后順序為:樹脂投加量㧐反應時間㧐反應溫度。201×7樹脂去除氟、氯離子的作用機理以離子交換為主;201×7樹脂對氟、氯離子的吸附過程較符合Langmuir等溫吸附模型。動力學研究表明,201×7樹脂對氟、氯離子的吸附反應可以用二級動力學模型解釋,離子交換吸附過程主要是吸附反應階段控制。動態(tài)吸附實驗時進水流速控制在28 m L/min較為合適,高徑比控制在6.25左右為宜。動態(tài)解析實驗以濃度為1mol/L的Na OH溶液為解吸劑,流速在5 m L/min時再生效果最佳。
[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：2139719