炭改良剂对复合污染土壤Cu的钝化效果

发布时间：2018-03-30 16:39

  本文选题：铜　切入点：复合污染　出处：《南昌航空大学》2016年硕士论文

【摘要】：随着经济的不断发展,重金属通过金属矿山的采矿、大气干湿沉降、污水灌溉农田、重金属超标农用制品的使用等途径进入到土壤中,造成土壤重金属严重污染。其中,铜冶炼厂排放了大量的Cu、Cd等重金属进入到土壤环境中,造成土壤铜镉复合污染,并使Cu在土壤中大量的积累。本文以清洁土壤为土培试验和盆栽试验的供试土壤,人为添加外源铜镉,添加量分别为400mg/g、5mg/g,以此模拟铜冶炼厂周边的已被污染的土壤。选用活性炭、低磷活性炭、HNO3改性活性炭、NaOH改性活性炭、KMnO_4改性活性炭、板蓝根生物炭、板蓝根药渣生物炭等13种炭材料为改良剂,根据对Cu的吸附效果,筛选出吸附性能良好的改良剂。再根据活性炭和KMnO_4改性活性炭对9种不同种类的污染土壤中的Cu的吸附率,选出土壤培养和盆栽试验的供试土壤,以黑麦草为指示植物,进行室内土壤培养实验和盆栽实验,分析几种钝化剂对Cu、Cd复合污染土壤的修复效果及作用机理。主要研究结果如下:不同炭改良剂对污染土壤的钝化效果表明:对于铜单一及铜镉复合污染的酸性土壤中,上述13种炭改良剂对Cu~(2+)的吸附作用均有不同程度地提高,其中,0.05mol/LKMnO_4改性活性炭对Cu~(2+)的去除效果较好,在添加量为2%时对Cu~(2+)的吸附率达到了80.56%。采用活性炭和KMnO_4改性活性炭对不同种类的污染土壤中Cu的钝化结果表明:上述2种炭改良剂对赤红壤(CHR0、CHR1)、黄壤(HUR0)、黄棕壤(HZR0)、广州红壤(HOR0)、江西红壤(HHR0、GYR0、NJR0)、暗棕壤(AZR0)等9种不同种类的污染土壤中Cu~(2+)的吸附率有不同程度的提高,且改性活性炭对Cu~(2+)的吸附效果高于活性炭的吸附效果。在铜单一污染土壤处理中,改性活性炭对土壤中Cu~(2+)的吸附率分别为95.73%、83.00%、86.69%、77.81%、87.14%、70.55%、95.43%、98.82%、54.06%;在铜镉复合污染土壤处理中,pH值在4.07~5.89范围内,对Cu~(2+)的吸附效果较好,改性活性炭对江西红壤(NJR0)的吸附率达到了98.82%。在土壤培养试验中,在铜单一污染土壤中,施加活性炭和改性活性炭后,土壤过氧化氢酶活性与对照相比有显著性提高,分别提高了45.45%、68.18%;脲酶活性分别提高了42.09%、32.97%。在铜镉复合污染土壤中,活性炭和改性活性炭与对照相比对土壤过氧化氢酶活性分别提高了61.90%、71.4%。在铜单一污染土壤中,改性活性炭的改良效果优于活性炭,酸可提取态、氧化结合态所占比例分别降低了5.79%、5.46%,有机结合态、残渣态分别提高了2.00%、9.25%;在铜镉复合污染土壤处理中,添加改良剂后,酸可提取态所占比例相较于单一铜处理提高幅度较大,分别增加了21.46%、5.73%,且具有酸可提取态、氧化结合态向有机结合态和残渣态转化的趋势。盆栽试验结果表明:活性炭、改性活性炭和麦饭石对黑麦草的生物量、叶绿素、根活力有所提高,能够降低黑麦草体内Cu的积累量,在铜单一污染土壤中,添加改性活性炭后,茎叶Cu、根Cu含量与无改良处理相比分别降低了35.30%、27.05%;在复合污染土壤中,添加活性炭、改性活性炭、麦饭石后,茎叶Cu、根Cu含量与对照相比分别降低了23.65%、32.08%、27.71%;27.41%、20.90%、28.83%。添加改良剂后,还可提高土壤pH值、增加有机质及土壤酶活性,降低Cu的酸可提取态含量,向潜在可利用态和不可利用态转化。炭改良剂对铜镉复合污染土壤具有良好的钝化效果,尤其是改性活性炭的使用,既不会带入新的污染物质,避免二次污染的风险,又能够有效的改良土壤环境。
[Abstract]:With the continuous development of the economy, heavy metal by metal mining, atmospheric deposition, sewage irrigation, use of agricultural products exceed the standard of heavy metals and other ways to enter into the soil, causing serious pollution of soil heavy metals. The copper smelter emissions of Cu, Cd and other heavy metals into the soil environment, soil pollution caused by compound copper and cadmium, and Cu in the soil. In this paper, the accumulation of large amounts of clean soil as tested soil culture experiment and pot experiment, adding exogenous copper and cadmium, adding amount of 400mg/g, 5mg/g, to simulate the copper smelter surrounding contaminated soil. Selection of activated carbon, activated carbon and low phosphorus HNO3, modified activated carbon, NaOH modified activated carbon KMnO_4 modified activated carbon, Radix biochar, Radix Isatidis residueconforms biochar and other 13 kinds of carbon materials as modifier, according to the effect of adsorption for Cu, selected good adsorption properties The improvement agent. According to the activated carbon and KMnO_4 modified activated carbon adsorption of 9 kinds of soil pollution in different kinds of Cu rate, the soils selected soil cultivation and pot experiment for ryegrass as indicator plants, experiment and pot experiment indoor soil cultivation, the analysis of several passivation agent on Cu, Cd composite remediation effect and mechanism. The main results are as follows: that the passivation effect of different carbon amendments on soil pollution: for acid soil copper single and composite copper and cadmium pollution in the 13 carbon amendment on Cu~ (2+) adsorption were improved in different degree, of which, 0.05mol/LKMnO_4 modified activated carbon on Cu~ (2+) good removal effect, when adding amount was 2% Cu~ (2+) on the adsorption rate of 80.56%. by activated carbon and KMnO_4 modified activated carbon on soil pollution in different kinds of Cu passivation results show that: 杩，

本文编号：1686737