三种环境材料对土壤铅镉固化及氮肥增效机理研究

发布时间：2018-05-19 22:07

本文选题：环境材料 + 重金属　；参考：《中国矿业大学(北京)》2016年博士论文

【摘要】：土壤污染特别是耕地污染问题事关食品安全和国家长远发展战略。农田土壤重金属污染、氮肥利用率低及面源污染等问题并存,威胁农业可持续发展和人体健康。因此,重金属污染治理和肥料增效等多重目标同步是农田土壤改良技术的重要目标,而寻求适宜的环境材料是获得多重目标同步的关键。环境材料是一类具有最大使用功能和最小环境负荷的材料,其特点是具有鲜明的功能性,环境友好性和经济性。为揭示环境材料对土壤铅镉固化和氮肥增效同步效应机理,本研究选用纳米碳、蛇纹石及褐煤腐殖酸三种环境材料,采用吸附解吸试验、砂柱及土柱淋溶试验、玉米发芽试验和盆栽种植等试验方法,开展三种环境材料对重金属铅、镉和氮素的吸附解吸特性、土壤铅、镉及氮素淋溶规律和效果、土壤有效态重金属铅、镉含量、重金属生物有效性和氮肥利用效率、土壤理化性质及其作物生长和品质影响的研究。结合材料表征分析,探讨了环境材料对重金属铅镉固化和氮肥增效同步效应机理,为纳米碳、蛇纹石及褐煤腐殖酸三种环境材料在土壤污染治理和土壤改良中的应用提供科学依据和技术参考。主要取得以下成果:1.通过模拟试验,研究了纳米碳、蛇纹石及褐煤腐殖酸三种环境材料对重金属铅(Pb~(2+))、镉(Cd~(2+))和铵(NH_4~+)离子的吸附特征、吸附稳定性及吸附机制。(1)获得了纳米碳、蛇纹石及褐煤腐殖酸对Pb~(2+)、Cd~(2+)和NH_4~+的最佳吸附条件。三种环境材料对Pb~(2+)、Cd~(2+)最佳吸附条件:纳米碳、蛇纹石及褐煤腐殖酸用量分别为2.5g/L、10.0 g/L和5.0g/L。溶液Pb~(2+)和Cd~(2+)初始浓度分别为600 mg/L和100 mg/L,反应温度25℃,p H=6.5,吸附时间180 min。三种环境材料对NH_4~+最佳吸附条件:纳米碳、蛇纹石及褐煤腐殖酸用量均为12.5 g/L,溶液NH_4~+初始浓度100 mg/L,反应温度25℃,p H=6.5(褐煤腐殖酸为4.5),吸附时间1440 min。(2)通过等温吸附试验及吸附动力学试验获得了三种环境材料对Pb~(2+)、Cd~(2+)和NH_4~+吸附机理及吸附性能。三种环境材料对Pb~(2+)和Cd~(2+)等温吸附曲线,使用Langumir等温吸附模型拟合度更好;纳米碳、蛇纹石及褐煤腐殖酸对Pb~(2+)的最大饱和吸附量分别为322.58 mg/g、55.87 mg/g和135.14 mg/g;纳米碳、蛇纹石及褐煤腐殖酸对Cd~(2+)的最大饱和吸附量分别为74.63 mg/g、15.24 mg/g和33.90mg/g;三种环境材料对Pb~(2+)和Cd~(2+)等温吸附过程属于优惠吸附、是吸热反应、吸附过程存在化学单层吸附;三种环境材料对Pb~(2+)和Cd~(2+)吸附动力学曲线,服从二级动力学模型,化学吸附占主导地位。三种环境材料对NH_4~+等温吸附曲线,使用Freundlich等温吸附模型拟合度更好;三种环境材料对对NH_4~+吸附过程属于优惠吸附、是吸热反应、吸附过程存在表面吸附,且为多层吸附;三种环境材料对NH_4~+吸附动力学曲线,服从二级动力学曲线,说明吸附过程存在化学吸附,但物理吸附占据主导地位。(3)获得了三种环境材料对Pb~(2+)、Cd~(2+)及NH_4~+最佳吸附稳定性条件。纳米碳、蛇纹石及褐煤腐殖酸对Pb~(2+)、Cd~(2+)吸附比较稳定。当6.5p H7.5时,Pb~(2+)、Cd~(2+)脱附率分别只有0.43%-0.95%。极端强酸性条件(p H=2.5),Pb~(2+)、Cd~(2+)脱附率分别低于21.53%和24.37%。纳米碳、蛇纹石及褐煤腐殖酸对NH_4~+吸附不稳定。当6.5p H7.5时,NH_4~+脱附率达到17.98%-19.91%。极端强酸性条件(p H=2.5),NH_4~+脱附率分别大于43.23%。这种性质对于其在土壤中的缓释效应具有重要意义。2.探讨了环境材料作用下Pb~(2+)、Cd~(2+)及NH_4~+的淋溶规律、淋溶效果,并获得了对Pb~(2+)、Cd~(2+)固化和NH_4~+保持效应最好的材料组合。(1)纳米碳对Pb~(2+)保持效果最好,褐煤腐殖酸对Cd~(2+)、NH_4~+保持效果最好;纳米碳及褐煤腐殖酸处理Pb~(2+)、Cd~(2+)及NH_4~+淋出率峰值出现在第二次淋溶试验,较CK及蛇纹石处理出现延迟;四次淋溶后,Pb~(2+)、Cd~(2+)及NH_4~+累积淋出率趋于稳定;三种环境材料对Pb~(2+)、Cd~(2+)及NH_4~+累积淋出率曲线能够按照Logistics模型拟合,纳米碳处理Pb~(2+)最大淋溶速率拐点出现最晚,褐煤腐殖酸处理Cd~(2+)、NH_4~+最大淋溶速率拐点出现最晚。(2)获得了对Pb~(2+)、Cd~(2+)固化及NH_4~+保持效应最佳环境材料及氮素组合:CN4AS4HA2N2。在土柱淋溶试验中,环境材料处理Pb~(2+)、Cd~(2+)及NH_4~+累积淋出率分别较对照CK降低14.62%-58.75%,12.81%-53.46%和1.03%-90.83%。3.以铅、镉胁迫下种子萌发试验和盆栽试验为基础,研究了三种环境材料对Pb~(2+)、Cd~(2+)生物有效性、环境材料及氮肥用量对作物生长、产量及品质的影响。(1)获得了影响玉米种子发芽的最低抑制浓度和玉米幼苗不同部位对Pb~(2+)、Cd~(2+)胁迫响应差异。Pb~(2+)、Cd~(2+)离子对玉米种子发芽率、发芽势的影响表现出低浓度促进,高浓度抑制,且浓度愈高抑制作用愈明显;玉米种子萌发对Cd~(2+)胁迫较Pb~(2+)敏感;Pb~(2+)、Cd~(2+)离子无论浓度高低,对于玉米种子芽长和根长伸长均起到抑制作用;玉米种子根长伸长对Pb~(2+)、Cd~(2+)离子胁迫响应较芽长伸长更为敏感。Pb~(2+)和Cd~(2+)抑制种子萌发的浓度分别为25 mg/L和15 mg/L。(2)环境材料能够促进重金属Pb~(2+)、Cd~(2+)胁迫下玉米发芽与生长。环境材料能够降低Pb~(2+)、Cd~(2+)胁迫对玉米种子的抑制作用,对于Pb~(2+)胁迫,纳米碳处理作用效果最佳,对于Cd~(2+)胁迫,褐煤腐殖酸处理作用效果最佳。(3)环境材料能够促进玉米增产,随氮肥用量增加玉米增产效应下降。环境材料处理玉米籽粒产量和地上部分干物质量较对照提高19.99%-59.72%和5.86%-30.35%。单一材料处理,纳米碳作用效果最佳;复合材料处理,纳米碳+褐煤腐殖酸+蛇纹石(CN+AS+HA)作用效果最佳;氮肥用量小于500 mg/kg时,玉米籽粒产量及地上部分干物质积累量随氮肥用量增大而增大;氮肥用量大于500 mg/kg时,玉米籽粒产量及地上部分干物质积累量随氮肥用量增大而减小。(4)环境材料可提高玉米可食用部分品质,氮肥用量增加降低玉米品质。环境材料处理玉米秸秆Pb~(2+)、Cd~(2+)含量较CK最大降幅分别为36.55%和40.72%;环境材料处理玉米籽粒Pb~(2+)、Cd~(2+)含量较CK最大降幅分别为39.66%和41.33%;单一环境材料处理,纳米碳作用效果最佳;复合材料处理,纳米碳+褐煤腐殖酸+蛇纹石(CN+AS+HA)作用效果最佳。玉米秸秆及籽粒重金属Pb~(2+)、Cd~(2+)含量随氮肥用量增加而增加。4.环境材料能够固化重金属、提高氮肥利用效率,改善土壤理化性质;氮肥用量增加能活化重金属,降低氮肥利用效率,不利于土壤理化性质改善。(1)环境材料能够固化重金属,降低有效态土壤重金属含量;增加氮肥用量则增加有效态土壤重金属含量。环境材料处理土壤有效态重金属Pb~(2+)、Cd~(2+)含量较CK降低4.38%-11.87%和2.78%-9.13%。单一材料处理,纳米碳作用效果最好。复合材料处理,纳米碳、蛇纹石及褐煤腐殖酸(CN+AS+HA)处理作用效果最好。土壤有效态重金属Pb~(2+)、Cd~(2+)含量随氮肥用量增加而增加。(2)环境材料能够提高氮肥利用效率,增加氮肥用量降低氮肥利用效率。环境材料处理氮肥利用效率(NUE)较对照提高3.41%-17.65%。单一材料处理,褐煤腐殖酸作用效果最佳。复合材料处理,纳米碳、蛇纹石及褐煤腐殖酸(CN+AS+HA)处理效果最佳。氮肥利用效率随氮肥用量增加而降低。(3)环境材料能改善土壤理化性质,增加氮肥用量不利于土壤理化性质改善。环境材料处理土壤有机质(SOM)和0.25-5.00 mm土壤团聚体含量较CK提高3.28%-32.36%和0.13%-11.02%。环境材料处理可减小土壤酸碱度(p H)、电导率(EC)和土壤阳离子交换量(CEC)降幅。单一材料处理,褐煤腐殖酸处理效果最佳。复合材料处理,纳米碳、蛇纹石及褐煤腐殖酸(CN+AS+HA)处理效果最佳。当氮肥用量小于400 mg/kg时,土壤有机质(SOM)含量随氮肥用量的提高而升高;当氮肥用量大于400 mg/kg时,土壤有机质(SOM)含量随氮肥用量的提高而降低。当氮肥用量小于300 mg/kg时,0.25-5.00 mm团聚体含量随氮肥用量增大而增大;当氮肥用量大于300 mg/kg时,0.25-5.00 mm团聚体含量占比随氮肥用量的提高而降低。土壤酸碱度(p H)随土壤氮肥施用增大而降低,电导率(EC)和土壤阳离子交换量(CEC)随氮肥用量增大而增大;种植玉米前后土壤酸碱度(p H)、电导率(EC)和土壤阳离子交换量(CEC)降幅随氮肥施用量增大而增大。5.通过材料表征技术,获得了环境材料的基本性能、官能团及形貌特征,探讨了环境材料对土壤铅、镉固化和氮肥增效机理。(1)获得了材料基本性能信息。纳米碳元素组成以C、H、O元素为主要组成部分;D50=11.37 nm,D90=61.53 nm;比表面积、孔径及孔体积分别为265.88 m2/g、4.63 nm和0.061 cm3/g。蛇纹石是一种富镁硅酸盐矿物;D50=18.82μm,D90=74.99μm;比表面积、孔径及孔体积分别为141.59 m2/g、10.36 nm和0.024 cm3/g。腐植酸主要由C、H、O、S等元素组成;D50=15.46μm,D90=63.47μm;比表面积、孔径及孔体积分别为13.64 m2/g、18.13 nm和0.004 cm3/g。电负性大小顺序:蛇纹石纳米碳褐煤腐殖酸。(2)明确了环境材料的化学官能团、形貌特征及化学组成,并分析了吸附前后化学官能团、形貌特征和化学组成变化的原因。FT-IR图谱表明,纳米碳、蛇纹石及褐煤腐殖酸中含有大量活性基团,其中部分官能团参与了Pb~(2+)、Cd~(2+)及NH_4~+离子吸附反应,吸附过程存在化学键的形成和断裂;场发射扫描电镜(SEM)结果显示,纳米碳、蛇纹石及褐煤腐殖酸表面微球、微孔及微球之间的空隙提供了吸附反应的场所;电子能谱(EDS)分析表明,Pb~(2+)、Cd~(2+)及NH_4~+吸附在了纳米碳、蛇纹石及褐煤腐殖酸表面。(3)探讨了纳米碳、蛇纹石及褐煤腐殖酸三种环境材料对土壤重金属铅、镉固化及氮肥增效作用机制。环境材料对重金属铅、镉固化及氮肥增效机理包含两个层面,一是环境材料直接与重金属铅、镉及氮素离子发生化学、物理吸附,降低有效态重金属含量,减缓氮素释放,提高氮素利用效率;二是通过环境材料对土壤理化性质改变,如通过提高土壤有机质含量、0.25-5.00 mm土壤团聚体含量、减小土壤电导率、阳离子交换量及土壤p H降幅,间接改变土壤有效态重金属含量,提高氮肥利用效率。
[Abstract]:The problem of soil pollution, especially the pollution of cultivated land, is related to food safety and the strategy of national parents' far development. The problems of heavy metal pollution in farmland, low utilization rate of nitrogen fertilizer and non-point source pollution are coexisting, which threaten the sustainable development of agriculture and human health. Therefore, multiple targets, such as heavy metal pollution control and fertilizer increase, are the technology of farmland soil improvement. The key objective is to seek suitable environmental materials, which is the key to the synchronization of multiple targets. The environmental material is a kind of material with the maximum use function and minimum environmental load. It is characterized by its distinctive function, environmental friendliness and economy. In this study, three kinds of environmental materials such as carbon nanoscale, serpentine and lignite humic acid were used. The adsorption and desorption test, sand column and soil column leaching test, Corn Germination Test and potted planting were used to carry out the adsorption and desorption characteristics of heavy metal lead, cadmium and nitrogen, soil lead, cadmium and nitrogen leaching laws and effects, soil soil, soil, soil, soil, soil, soil, soil and soil. The effects of heavy metal lead, cadmium content, bioavailability and nitrogen use efficiency of heavy metals, soil physical and chemical properties and crop growth and quality were studied. Combined with the analysis of material characterization, the mechanism of simultaneous effect of environmental materials on heavy metal lead and cadmium solidification and nitrogen fertilizer synergism was discussed, which were three environmental materials for nano carbon, serpentine and lignite humic acid. The scientific basis and technical reference are provided in the application of soil pollution control and soil improvement. The following achievements are made as follows: 1. through simulation experiments, the adsorption characteristics, adsorption stability and adsorption mechanism of three environmental materials of nano carbon, serpentine and lignite humic acid on heavy metal lead (Pb~ (2+)), cadmium (Cd~ (2+)) and ammonium (NH_4~+) ions were studied. (1) the optimum adsorption conditions for Pb~ (2+), Cd~ (2+) and NH_4~+ were obtained from nano carbon, serpentine and lignite humic acid. The best adsorption conditions for Pb~ (2+) and Cd~ (2+) were obtained by three environmental materials: the dosage of nano carbon, serpentine and lignite humic acid were 2.5g/L, 10 g/L and 5.0g/L. solutions were 600 and 100 respectively. The optimum adsorption conditions for NH_4~+ were at 25 C, P H=6.5, and adsorption time 180 min.. The dosage of nano carbon, serpentine and lignite humic acid were 12.5 g/L, the initial concentration of NH_4~+ was 100 mg/L, the reaction temperature was 25, P H=6.5 (lignite humic acid 4.5), and adsorption time 1440 min. (2) through isothermal adsorption test and adsorption kinetics test. The adsorption mechanism and adsorption properties of three environmental materials on Pb~ (2+), Cd~ (2+) and NH_4~+ were obtained. The adsorption curves of Pb~ (2+) and Cd~ (2+) by three environmental materials were better than that of Langumir isothermal adsorption model, and the maximum saturated adsorption capacity of nano carbon, serpentine and lignite humic acid to Pb~ (2+) was 322.58, 55.87 and 135. respectively. 14 mg/g; the maximum saturated adsorption capacity of nano carbon, serpentine and lignite humic acid to Cd~ (2+) was 74.63 mg/g, 15.24 mg/g and 33.90mg/g, respectively. The isothermal adsorption process of Pb~ (2+) and Cd~ (2+) was preferential adsorption for three environmental materials, endothermic reaction, and adsorption process with chemical monolayer adsorption; three environmental materials adsorbed Pb~ (2+) and adsorbents. The mechanical curve is subject to the two stage dynamic model, chemical adsorption is dominant. Three kinds of environmental materials have better fitting degree to NH_4~+ isothermal adsorption curve and Freundlich isothermal adsorption model; three kinds of environmental materials have preferential adsorption to NH_4~+ adsorption process, endothermic reaction, adsorption process surface adsorption, and multi-layer adsorption; three kinds of adsorption; The adsorption kinetics curve of the environmental material obeys the two order kinetics curve, which shows that the adsorption process is chemisorption, but physical adsorption occupies the dominant position. (3) the optimum adsorption stability conditions of three environmental materials for Pb~ (2+), Cd~ (2+) and NH_4~+ are obtained. The adsorption of nano carbon, serpentine and lignite humic acid on Pb~ (2+) and Cd~ (2+) is stable. When 6.5p H7.5, the desorption rate of Pb~ (2+) and Cd~ (2+) is only the extreme strong acidic condition of 0.43%-0.95%. (P H=2.5), Pb~ (2+), and the desorption rate of the Cd~ is less than 21.53% and nanometer carbon respectively. The desorption rate of + + is greater than 43.23%., which is of great significance to the slow release effect in soil..2. explores the leaching laws of Pb~ (2+), Cd~ (2+) and NH_4~+, leaching effect, and obtained the best combination of Pb~ (2+), Cd~ (2+) curing and NH_4~+ holding effect. (1) carbon nanoscale keeps the most effective. Well, lignite humic acid has the best effect on Cd~ (2+) and NH_4~+, and the peak value of Pb~ (2+), Cd~ (2+) and NH_4~+ leaching rate in the second leaching tests, compared with CK and serpentine treatment, is delayed, and Pb~ (2+), Cd~ (2+) and accumulation rate tend to be stable after four leaching; three environmental materials The cumulative leaching rate of NH_4~+ can be fitted to the Logistics model. The maximum leaching rate of Pb~ (2+) is the latest, Cd~ (2+) is treated with lignite humic acid, and the maximum inflexion point of the leaching rate of NH_4~+ is the latest. (2) the best environmental material and nitrogen combination for Pb~ (2+), Cd~ (2+) curing and NH_4~+ retention effect are obtained. In the soil column leaching test, the cumulative leaching rate of Pb~ (2+), Cd~ (2+) and NH_4~+ decreased by 14.62%-58.75%, 12.81%-53.46% and 1.03%-90.83%.3. were based on the seed germination test and pot experiment under lead, cadmium stress, and three kinds of environmental materials were studied for the Pb~ (2+), the environmental material and the nitrogen fertilizer. The influence of quantity on crop growth, yield and quality. (1) the minimum inhibitory concentration of Maize Seed Germination and the difference of Pb~ (2+), Cd~ (2+) stress response of maize seedlings to different parts were.Pb~ (2+). The effect of Cd~ (2+) ions on the germination rate and germination potential of maize showed low concentration promotion, high concentration inhibition and higher inhibition effect. The germination of maize seeds was more sensitive to Cd~ (2+) stress than that of Pb~ (2+); Pb~ (2+), Cd~ (2+) ions, regardless of the concentration, could inhibit the bud length and length elongation of maize seeds, and the length elongation of maize seed root length to Pb~ (2+), Cd~ (2+) stress should be more sensitive than the length of bud length. Not 25 mg/L and 15 mg/L. (2) environmental materials can promote the germination and growth of heavy metals under the stress of Pb~ (2+), Cd~ (2+) stress. Environmental materials can reduce Pb~ (2+), Cd~ (2+) stress on maize seeds, for Pb~ (2+) stress, the effect of carbon nanoscale treatment is the best. (3) the effect of lignite humic acid treatment is the best. Environmental materials could increase the yield of maize, and the effect of maize yield increased with the amount of nitrogen fertilizer. The yield of maize grain and the quality of the dry matter on the ground were improved by 19.99%-59.72% and 5.86%-30.35%. single material treatment, and the effect of carbon nanomaterials was the best. A) the effect was the best. When the amount of nitrogen fertilizer was less than 500 mg/kg, the yield of corn grain and the accumulation of dry matter on the ground increased with the increase of nitrogen fertilizer. When the amount of nitrogen fertilizer was greater than 500 mg/kg, the grain yield and the accumulation of dry matter on the ground decreased with the increase of the amount of nitrogen fertilizer. (4) the quality of edible part of corn could be improved by environmental materials. The content of nitrogen fertilizer increased to reduce the quality of corn. The content of maize straw Pb~ (2+) and Cd~ (2+) was 36.55% and 40.72%, respectively. The content of Pb~ (2+) and Cd~ (2+) in maize grains treated by environmental materials was 39.66% and 41.33%, respectively, compared with CK, and the effect of carbon nanomaterials was the best. The effect of M C + lignite humic acid + serpentine (CN+AS+HA) is the best. The content of heavy metal Pb~ (2+) and Cd~ (2+) in corn straw and grain increases with the increase of nitrogen fertilizer, and the.4. environment material can solidify heavy metals, improve the utilization efficiency of nitrogen fertilizer and improve the physical and chemical properties of soil; the increase of nitrogen fertilizer can activate heavy metals and reduce the utilization efficiency of nitrogen fertilizer. The physical and chemical properties of soil improved. (1) environmental materials can solidify heavy metals, reduce the content of heavy metals in effective soil, and increase the amount of effective soil heavy metals by increasing the amount of nitrogen fertilizer. Environmental materials treat soil available heavy metals Pb~ (2+), Cd~ (2+) content is lower than 4.38%-11.87% and 2.78%-9.13%. single material treatment, and the effect of carbon nanoscale The best effects were treated with composite materials, carbon nanoscale, serpentine and lignite humic acid (CN+AS+HA) treatment. The soil effective heavy metal Pb~ (2+), Cd~ (2+) content increased with the amount of nitrogen fertilizer. (2) environmental materials can improve nitrogen use efficiency and increase nitrogen fertilizer application efficiency. Rate (NUE) improved 3.41%-17.65%. single material treatment, lignite humic acid was the best. Composite treatment, carbon nanoscale, serpentine and lignite humic acid (CN+AS+HA) treatment was the best. Nitrogen utilization efficiency decreased with the increase of nitrogen fertilizer. (3) environmental material can improve soil physical and chemical properties, increasing the amount of nitrogen fertilizer is not conducive to soil. Improvement in physical and chemical properties. Soil organic matter (SOM) and 0.25-5.00 mm soil aggregate content is higher than CK, 3.28%-32.36% and 0.13%-11.02%. environmental material treatment can reduce soil pH (P H), conductivity (EC) and soil cation exchange (CEC) decrease. Single one material treatment, lignite humic acid treatment effect is the best. Treatment, carbon nanoscale, serpentine and lignite humic acid (CN+AS+HA) had the best treatment effect. When the amount of nitrogen fertilizer was less than 400 mg/kg, the content of soil organic matter (SOM) increased with the increase of the amount of nitrogen fertilizer. When the amount of nitrogen fertilizer was greater than 400 mg/kg, the content of soil organic matter (SOM) decreased with the increase of nitrogen fertilizer amount. When the amount of nitrogen fertilizer was less than 300 mg/kg, 0.25, the content of nitrogen fertilizer was less than 300 mg/kg. The content of -5.00 mm aggregates increased with the increase of nitrogen fertilizer amount; when the amount of nitrogen fertilizer was greater than 300 mg/kg, the proportion of 0.25-5.00 mm aggregate content decreased with the increase of nitrogen fertilizer. The soil pH (P H) decreased with the increase of soil nitrogen application, and the conductivity (EC) and the exchange amount of soil Yang (CEC) increased with the increase of nitrogen fertilizer. The soil pH (P H), electrical conductivity (EC) and soil cation exchange capacity (CEC) decreased with the increase of nitrogen fertilizer amount and increased.5. through material characterization technology. The basic properties of environmental materials, functional groups and morphology characteristics were obtained. The mechanism of environmental materials on soil lead, cadmium solidification and nitrogen fertilizer synergism was discussed. (1) the basic properties of the materials were obtained. C, H, and O elements are the main components, D50=11.37 nm, D90=61.53 nm, the specific surface area, the pore size and the pore volume are 265.88 m2/g, 4.63 nm and 0.061 cm3/g. serpentine are magnesium rich silicate minerals, D50=18.82 micron m, and the pore size and pore volume are 141.59, 10.36 and 0.024, respectively. Cm3/g. humic acid mainly consists of C, H, O, S and other elements; D50=15.46 mu m, D90=63.47 mu m; the specific surface area, pore size and pore volume are 13.64 m2/g, 18.13 nm and 0.004 cm3/g. electronegativity sequence: serpentine nano carbon lignite humic acid. (2) clear the environmental material of the chemical group, morphology and chemical composition, and analyzed the adsorption before and after adsorption .FT-IR maps of chemical functional groups, morphologies and chemical composition changes show that carbon nanoscale, serpentine and lignite humic acid contain a large number of active groups, in which some functional groups are involved in Pb~ (2+), Cd~ (2+) and NH_4~+ ion adsorption, and the adsorption process has the formation and fracture of chemical bonds; field emission scanning electron microscopy (SEM) results show that Nanoscale, serpentine and lignite humic acid surface microspheres, micropores and microspheres provide a place for adsorption reaction. EDS analysis shows that Pb~ (2+), Cd~ (2+) and NH_4~+ are adsorbed on carbon nanoscale, serpentine and lignite humic acid. (3) three environmental materials of nano carbon, serpentine and lignite humic acid are discussed. The mechanism of heavy metal lead, cadmium solidification and nitrogen fertilizer synergism. There are two levels of environmental materials on heavy metal lead, cadmium solidification and nitrogen fertilizer synergistic mechanism.
【学位授予单位】：中国矿业大学(北京)
【学位级别】：博士
【学位授予年份】：2016
【分类号】：S153;X53

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