【摘要】：為了弄清幾種含鎘化合物在自然環(huán)境條件下的溶出性能,以及降低含鎘廢渣對環(huán)境的污染。本文利用人工制備幾種含鎘化合物在模擬自然環(huán)境的條件下進行溶出反應,對幾種化合物在相同條件下的溶出結(jié)果進行比較,研究其相對穩(wěn)定性。在此基礎(chǔ)上以廣西河池某廠的含鎘廢渣為研究對象,通過溶出實驗探索廢渣中鎘的溶出性能,研究含鎘廢渣穩(wěn)定化的有效方法,選擇硫化鈉和氫氧化鈉為穩(wěn)定劑,探索含鎘廢渣穩(wěn)定化處理的工藝條件,通過浸出毒性對穩(wěn)定化效果進行表征。其結(jié)果如下：(1)反應時間、反應溫度和溶液pH對含鎘化合物中鎘的溶出均有一定的影響,表現(xiàn)為反應時間的延長、反應溫度的升高和溶液pH的減小均使鎘的溶出率得到提高,其中溶液pH是主要影響因素。(2)通過對三種含鎘化合物溶出反應的比較,硫化鎘在三種化合物中最為穩(wěn)定,相同反應條件下鎘的溶出率要比碳酸鎘和氫氧化鎘低得多。(3)在實驗范圍內(nèi),含鎘廢渣中鎘的最佳溶出工藝條件為：攪拌速度300r.min-1,反應時間30min,液固比4：1,溶液pH=1.0,反應溫度60℃。在此條件下,鎘的溶出率僅為1.183%,因此該廢渣中的鎘不宜進行回收利用。溶出反應后廢渣的浸出毒性為2.351mg.L-1,與未處理廢渣浸出毒性2.99mg.L1相比變化不大,未達到將危險廢物轉(zhuǎn)化為一般固廢的要求。(4)含鎘廢渣經(jīng)穩(wěn)定化處理后,浸出毒性明顯降低,且遠低于國家標準。在實驗范圍內(nèi)最優(yōu)實驗條件為：加入硫化鈉：機械攪拌速度300r.min-1、反應時間40min、液固比3：1、硫化鈉濃度0.5 mo1.L-1,常溫下反應,在此條件下,處理后渣樣浸出毒性為0.0275 mg.L-1；加入氫氧化鈉：機械攪拌速度300r.min-1、反應時間30min、液固比4：1、氫氧化鈉濃度1.0 mo1.L-1,常溫下反應,在此條件下,處理后渣樣浸出毒性為0.0324 mg.L-1。
[Abstract]:In order to understand the dissolution performance of several cadmium compounds in natural environment and reduce the environmental pollution caused by the waste residue containing cadmium. In this paper, the dissolution reaction of several cadmium compounds was carried out under simulated natural environment. The results of dissolution of several compounds under the same conditions were compared and their relative stability was studied. On this basis, the cadmium containing waste residue of a factory in Hechi, Guangxi, was taken as the research object. The dissolution performance of cadmium in the waste residue was explored through dissolution experiments, and the effective method of stabilizing the waste residue containing cadmium was studied. Sodium sulphide and sodium hydroxide were selected as stabilizers. The stabilization effect of cadmium-containing waste residue was characterized by leaching toxicity. The results are as follows: (1) reaction time, reaction temperature and solution pH have a certain effect on the dissolution of cadmium from cadmium compounds, as shown by the prolongation of reaction time. The dissolution rate of cadmium was increased with the increase of reaction temperature and the decrease of solution pH, among which solution pH was the main influencing factor. (2) cadmium sulfide was the most stable in the three compounds by comparing the dissolution reaction of three kinds of cadmium containing compounds. Under the same reaction conditions, the dissolution rate of cadmium is much lower than that of cadmium carbonate and cadmium hydroxide. (3) in the experimental range, the optimum technological conditions for the dissolution of cadmium in waste residue containing cadmium are as follows: stirring speed 300r.min-1, reaction time 30min, liquid-solid ratio 4: 1, The solution pH=1.0, reaction temperature is 60 鈩，

本文編號：2407769