本文選題：含砷石膏 + 穩(wěn)定化��； 參考：《廣西大學》2015年碩士論文

【摘要】：本文對砷的性質(zhì)、含砷石膏的來源、污染和治理進行了綜合論述。以硫酸廠的含砷石膏和實驗室自制的高砷含量石膏為研究對象,采用加溫轉(zhuǎn)晶穩(wěn)定化和藥劑穩(wěn)定化兩種方法對其進行穩(wěn)定化處理,并對穩(wěn)定化效果進行檢測和比較。實驗采用正交實驗和單因素實驗設計方法考察各因素對穩(wěn)定化效果的影響規(guī)律,參照HJ/T299-2007固體廢棄物浸出毒性浸出方法,檢測含砷石膏的穩(wěn)定化效果。采用硫酸硝酸水平振蕩法對其進行浸出性能研究,為屬危險廢物(下稱危廢)的含砷石膏的危害性評估、無害化處理提供基礎數(shù)據(jù)。經(jīng)毒性浸出實驗數(shù)據(jù)顯示,處理前砷含量分別為1.3%、2.8%、5.8%和7.2%的含砷石膏,其砷的毒性浸出濃度依次為8.0 mg·L-1、12.0 mg·L-1、25.6 mg.L-1和52.5 mg.L-1,均大于5 mg.L-1(一般廢物的浸出毒性砷濃度限值),表明處理前含砷石膏均為危險廢物。穩(wěn)定化處理后含砷石膏的砷的毒性浸出濃度顯著降低。對于晶型轉(zhuǎn)化法,在處理時間為5 h時,優(yōu)化的轉(zhuǎn)晶溫度分別為140℃、140℃、200℃和250℃進行轉(zhuǎn)晶穩(wěn)定化處理。經(jīng)處理后的含砷石膏浸出毒性砷濃度分別為4.1 mg·L-1、4.25 mg·L-1、3.9 mg·L-1和4.5 mg.L-1。使屬危廢的含砷石膏轉(zhuǎn)變成穩(wěn)定的一般固體廢物。鐵鹽穩(wěn)定化試驗中,鐵砷摩爾比是影響穩(wěn)定化效果的主要因素。在反應時間為15 mmin,溫度為30℃,pH為6.86,為達到較好的穩(wěn)定化效果,處理砷含量分別為1.3%、2.8%、5.8%和7.2%的含砷石膏,所需的硫酸鐵的優(yōu)化鐵砷摩爾比分別為1、1、2.5和3,處理后四種含砷石膏浸出毒性砷濃度依次為1.27 mg·L-1、4.23 mg·L-1、4.1 mg·L-1和7.2 mg.L-1。聚合硫酸鐵的優(yōu)化鐵砷摩爾比分別為1、1、2和2.5,處理后四種含砷石膏浸出毒性砷濃度依次為1.13 mg·L-1、1.23 mg·L-1、3.3 mg·L-1和3.78 mg.L-1。由浸出毒性的結果可知,砷含量在6%以下的含砷石膏,砷含量愈高穩(wěn)定化時所需的鐵砷摩爾比愈高。但砷含量再高的時候,再用硫酸鐵作為穩(wěn)定劑進行穩(wěn)定化處理時,就不能達到理想效果了。而聚合硫酸鐵均可以使砷含量在1-7%的含砷石膏轉(zhuǎn)化為一般廢物。轉(zhuǎn)晶穩(wěn)定化和鐵鹽穩(wěn)定化均可作為含砷石膏穩(wěn)定化的方法,但轉(zhuǎn)晶穩(wěn)定化時間長,溫度高,操作復雜,而鐵鹽穩(wěn)定化的反應時間短,反應速度快,工藝相對來說更容易實現(xiàn)工業(yè)化。
[Abstract]:The properties, sources, pollution and treatment of arsenic-containing gypsum are discussed in this paper. Taking arsenic gypsum in sulphuric acid plant and gypsum with high arsenic content in laboratory as the research object, the stabilization treatment was carried out by using two methods of temperature-changing crystallization stabilization and medicament stabilization, and the stabilization effect was tested and compared. The effects of various factors on stabilization effect were investigated by orthogonal experiment and single factor experimental design. The stabilization effect of arsenic-containing gypsum was detected by referring to HJ/T299-2007 solid waste leaching toxicity leaching method. The leaching performance of sulfuric acid nitric acid horizontal oscillation method is studied, which provides basic data for hazard assessment and innocuous treatment of arsenic-containing gypsum belonging to hazardous waste (hereinafter referred to as hazardous waste). The experimental data of toxic leaching showed that the arsenic content before treatment was 1.32.8wt% and 7.2% arsenic-containing gypsum, respectively. The toxic leaching concentration of arsenic was 8.0 mg / L ~ (-1) 12.0 mg / L ~ (-1) 25.6 mg.L-1 and 52.5 mg 路L ~ (-1) respectively, both of which were higher than 5 mg 路L ~ (-1) (the limit value of arsenic concentration was 5 mg 路L ~ (-1)), which indicated that arsenic-containing gypsum was hazardous waste before treatment. The toxic leaching concentration of arsenic in arsenic gypsum decreased significantly after stabilization treatment. For the method of crystal transformation, when the treatment time is 5 h, the optimized transgranular temperature is 140 鈩，

本文編號：1776665