【摘要】：隨著人們對環(huán)境重視程度的逐漸提高,越來越關(guān)心身邊的環(huán)境質(zhì)量,所以對環(huán)境的治理已經(jīng)迫在眉睫。在眾多的污染物之中,砷是一種污染極其嚴(yán)重的污染物,其來源廣泛,例如工業(yè)排放的廢水和固體垃圾填埋廠的廢液中均含有砷。砷通過食物鏈的逐級絮集,進(jìn)一步造成環(huán)境的嚴(yán)重的污染和對人體產(chǎn)生極大的損害。人們常用絮凝沉淀、物理與化學(xué)吸附、生物吸附等方法處理砷離子。輕燒氧化鎂與粉煤灰復(fù)合礦物應(yīng)用于砷污染廢水的處理,具有便于操作、可行性高、成本低等特點(diǎn)。制備的輕燒氧化鎂與粉煤灰復(fù)合礦物材料,可以有效的吸附水溶液中的重金屬砷。本文主要以重金屬砷為研究對象,將菱鎂礦進(jìn)行煅燒獲得高活性的輕燒氧化鎂,再以輕燒氧化鎂-粉煤灰復(fù)合礦物材料為吸附劑,通過對普通的礦物質(zhì)材料進(jìn)行改性,增加其利用價值,對不同影響因素下的砷具有較好的吸附效果。首先,對復(fù)合吸附劑(輕燒氧化鎂-粉煤灰)在不同條件下的改性,實(shí)驗(yàn)結(jié)果表明:用固液比為7g/L的復(fù)合吸附劑在混酸溶液(1mol/L HCl和1mol/L H_2SO_4)中進(jìn)行酸浸漬,其中混酸(HCl:H_2SO_4)的體積比為2:1,總酸與復(fù)合吸附劑的液固比為5:1(v/m),60℃的溫度下進(jìn)行活化處理,在活化的過程中加入鐵粉0.15 g/L,NaCl 1g/L,經(jīng)過60 min的勻速攪拌,得到具有良好吸附性能的復(fù)合吸附劑。其次,探討復(fù)合礦物材料治理砷污染廢水的最佳條件。實(shí)驗(yàn)結(jié)果表明:復(fù)合吸附劑的用量、溶液的pH、吸附時間、吸附溫度、溶液的初始濃度等因素對復(fù)合吸附劑對砷的吸附效果有影響。實(shí)驗(yàn)過程中,含砷溶液的初始濃度為2 mg/L,pH為9.81左右,加入吸附劑的量為2 g/L,吸附溫度45℃,吸附時間90 min,改性吸附劑對砷的去除率達(dá)到85%左右,對于低濃度溶液中的砷的吸附效果達(dá)到理想預(yù)期。最后,為了探究復(fù)合吸附劑對砷(V)的吸附機(jī)理,通過掃描電鏡、零電位測試對其進(jìn)行表征,主要對改性吸附劑結(jié)構(gòu)形態(tài)進(jìn)行分析。結(jié)果表明:改性吸附劑的表面孔隙變大,比表面積變大,活性基團(tuán)的數(shù)量增加,無機(jī)絮凝劑的含量增加,這些變化決定了對砷(V)具有良好的吸附效果。
[Abstract]:As people pay more and more attention to the environment, they are more and more concerned about the environmental quality around them. Among the many pollutants, arsenic is a kind of extremely serious pollution pollutant, its source is widespread, for example, the industrial waste water and the solid waste landfill waste liquid all contain arsenic. Arsenic can cause serious environmental pollution and great damage to human body through the successive flocs in the food chain. Flocculation precipitation, physical and chemical adsorption, and biological adsorption are commonly used to treat arsenic ion. The application of light burned magnesium oxide and fly ash compound minerals to the treatment of arsenic-polluted wastewater has the advantages of easy operation, high feasibility, low cost and so on. The composite mineral material of light burning magnesium oxide and fly ash can effectively adsorb arsenic in aqueous solution. In this paper, magnesium oxide with high activity was obtained by calcination of magnesite, and then the ordinary mineral material was modified by using the composite mineral material of light burning magnesium oxide and fly ash as adsorbent. By increasing its utilization value, it has a better adsorption effect on arsenic under different influence factors. First of all, the modification of composite adsorbent (light burning magnesia fly ash) under different conditions, The experimental results show that the composite adsorbent with solid / liquid ratio of 7g/L is impregnated with acid in mixed acid solution (1mol/L HCl and 1mol/L H_2SO_4), where the volume ratio of HCl:H_2SO_4 is 2: 1. The liquid-solid ratio of total acid to composite adsorbent is 5:1 (v / m), and the activation treatment is carried out at 60 鈩，

本文編號：2305418