Knowledge Resource Center for Ecological Environment in Arid Area
| 脱硫石膏改良碱土过程中大气CO2吸收强度研究 | |
| 其他题名 | Research on Atmospheric CO2 Absorption Intensity of FGD Gypsum in Improving Alkaline Soil |
| 雒琼 | |
| 出版年 | 2018 |
| 学位类型 | 硕士 |
| 导师 | 马健 |
| 学位授予单位 | 中国科学院大学 |
| 中文摘要 | 随着世界人口的持续增长和可利用土地面积的逐渐减小，盐碱土已成为土地开发利用中较为重要的土地资源。干旱区由于其特殊的气候特点，土壤盐碱化已成为制约干旱区域农业发展和生态环境改善的突出问题，因此干旱区的盐碱土改良尤为迫切。脱硫石膏是燃煤电厂脱硫技术的工业废弃物，作为改善盐渍化的有效手段之一，不仅加强了废弃物的资源化利用，同时也减少了对土地资源的污染，这对于我国可持续发展战略和循环经济理念具有重大的现实意义。由此，利用脱硫石膏改善盐渍化现象成为农业生产中一个较为关注的问题。与此同时，以CO2为主的温室气体所引发的全球气候变化已成为全世界关切的热点问题，由此减缓全球气候变化也成为了目前人类发展的首要任务。而土壤碳库作为陆地生态系统中最大的碳库，也是与人类联系最紧密的碳库，持续与大气CO2发生着最为直接的交互作用，而盐碱土改良作为目前较为频繁发生的土地利用措施，将必然改变地-气系统中CO2的吸收机制和吸收速率，因此，该项研究的开展，不仅能够确定区域碱土改良的农业可持续发展模式在减缓大气CO2的贡献，同时也可以为电厂废弃物脱硫石膏的资源回收再利用模式提供一条直接便利的途径。这一方面对于我们正确认识干旱区碳汇问题提供重要的数据支持，另一方面对于我们认识在当前气候变化背景下对区域生态环境改善的促进作用具有深远的意义。 本研究选取干旱区pH值为8.5-10.5范围内的5种典型碱土作为研究对象，以室内装填土柱模拟淋溶法为研究手段，通过添加不同量的脱硫石膏，通过定时采集土壤样品，结合土壤呼吸数据以及与之相对应的化学分析数据，评价盐碱土的改良效果；通过土壤和淋溶液中有机碳和无机碳的储量测定，量化改良过程中大气CO2的吸收强度；最后基于以上数据，分析各环境要素与大气CO2吸收强度之间的关系。结果表明： （1）在0-60 cm的深度中pH值、碱化度以及钠吸附比的降低程度为0-20 cm > 20-40 cm > 40-60 cm（p<0.05），在一定的脱硫石膏添加范围内，pH值、碱化度（ESP）和钠吸附比（SAR）的减小程度与脱硫石膏添加量呈现正相关趋势。在0-20 cm深度的改良层中pH随时间出现先下降后上升，最后趋于稳定的状态，而在20-40 cm和40-60 cm的深度中pH值随时间变化的幅度小于0-20 cm的改良层。 （2）通过CO2通量变化可以证实脱硫石膏改良盐碱土过程中存在大气CO2吸收过程，且可以把整个过程分为三个阶段，0-12天左右的反应阶段，12-18天左右的稳定阶段，18天之后的自然波动阶段。 （3）当初始无机碳（SIC）含量较大时，SIC随时间土壤无机碳含量在最初呈现显著下降趋势（p<0.05），之后逐渐波动；而当初始土壤无机碳较低时，SIC在整个过程中波动较小且一直趋于稳定。而随着脱硫石膏添加量的增加，土壤无机碳含量在各层次均呈现不显著增加现象；土壤有机碳（SOC）含量在各层次基本趋于稳定，整个过程中并无太大波动，但整体上，随着脱硫石膏添加量的不同，最终的SOC含量不尽相同但差异性并不显著（p>0.05）。 （4）根据公式计算得出不同初始pH值的大气CO2吸收强度，可以得到的范围为0.04±0.012 kg/m2 - 0.91±0.009 kg/m2，且土壤的改良效果与碳吸收量并不完全成正比。通过拟合各初始pH值表现出随脱硫石膏添加量的增加大体表现为逐渐增加趋势；根据不同初始pH值土壤计算得出的最佳脱硫石膏添加量得到各组相对应的大气CO2吸收量，其随初始pH值的增加表现为先降低后升高的趋势，变化范围为0.29 kg/m2-0.81kg/m2，最终通过拟合得到拟合公式（R2=0.98，P<0.05）。 （5）通过冗余分析（RDA）得到各环境因子与大气CO2吸收量的关系，结果显示正相关性排序为：脱硫石膏添加量> CO32 -> K+ >土壤含水率> SO42-，负相关性排序为：初始pH值> Cl- > Ca2+ > SAR > ESP > Na+ > pH > EC。 |
| 英文摘要 | As the world population continues to grow and the available land area decreases gradually, saline-alkaline soil has become the more important land resource in land development and utilization. Due to its special climatic characteristics in arid area, soil salinization has become a prominent problem restricting the agricultural development and ecological environment improvement in arid areas. Therefore, the improvement of saline-alkaline soil in arid areas is of crucial importance. Flue gypsum desulphurization (FGD) is an industrial waste of desulphurization technology in coal-fired power plant. As one of the effective means to ameliorate saline-alkali soil, it not only enhances the utilization of desulphurization gypsum but also reduces the pollution of land resources, which is very important for our country's sustainable development strategy and circular economy Idea. Therefore, the amelioration of saline-alkali soil by FGD has become a concerned issue in the development of agricultural land. At the same time, global climate change triggered by CO2-based greenhouse gases has become a hot issue in the world. Therefore, mitigation of global climate change has also become the top priority for human development. Soil carbon pool, as the largest carbon sink in terrestrial ecosystems and also the most closely linked carbon pool with human, has the most direct interaction with atmospheric CO2. However, the amelioration of saline-alkali soil, as the most frequently used land-use measure, will inevitably change the absorption mechanism and absorption rate of CO2 in the geo-gas system. Therefore, the study can not only determined the contribution to reducing atmospheric CO2 in the mode of agricultural sustainable development with improved alkaline earth in the region, but also can contribute to the reduction of atmospheric CO2, providing a direct and convenient way for resource recovery and reuse mode of power factory waste FGD gypsum. This study can provides important data for our correct understanding of the issue of carbon sequestration in the arid region. It has far-reaching significance for us to recognize the role of promoting the improvement of regional ecological environment in the current background of climate change. In this study, five alkaline soils with pH range of 8.5-10.5 in the arid region were selected as the research object. Taking the simulated leaching method of indoor filling soil column as the research method, by adding different amounts of gypsum. The improvement of saline-alkali soil was evaluated based on the soil respiration data and the corresponding chemical analytical data. The atmospheric CO2 absorption intensity during the improvement was quantified through the determination of organic carbon and inorganic carbon in soil and leaching solution. Finally, based on the above data, analysis of the relationship between environmental factors and atmospheric CO2 absorption intensity. The results showed the following: (1)The decrease in pH, alkalinity, and sodium adsorption ratio at 0-60 cm depth is 0-20 cm> 20-40 cm> 40-60 cm (p < 0.05). Within a certain range of amount of desulfurized gypsum addition, the degree of decrease in pH, alkalinity, and sodium adsorption ratio is positively correlated with the amount of desulfurized gypsum. In the 0-20 cm depth of the modified layer, the pH first decreased , then rose, and finally stabilized with time. At 20-40 cm and 40-60 cm depth, the pH value was less improved than that of layer of 0-20 cm. (2)Through measuring the CO2 flux change, it can be confirmed that there is an atmospheric CO2 absorption process during desalination gypsum improvement of saline-alkaline soil. The whole process is divided into three stages, a reaction stage of about 0-12 days, a stable stage of about 12-18 days, and a natural fluctuation stage after 18 days. (3) When the initial inorganic carbon content is large, the soil inorganic carbon content (SIC) shows a significant downward trend (p<0.05) at="" then="" gradually="" stabilizes.="" when="" the="" initial="" soil="" inorganic="" carbon="" is="" fluctuations="" of="" are="" small="" and="" they="" tend="" to="" be="" stable="" in="" whole="" process.="" with="" increase="" amount="" desulfurized="" content="" showed="" an="" increasing="" trend="" all="" levels.="" organic="" basically="" stabilized="" there="" was="" not="" much="" fluctuation="" but="" desulfurization="" gypsum="" final="" soc="" same="" difference="" significant="" p="">0.05). (4) Calculate the atmospheric CO2 absorption intensity of different initial pH values according to the formula, the range of atmospheric CO2 absorption is 0.04±0.012 kg/m2 - 0.91±0.009 kg/m2, and the soil improvement effect is not proportional to the carbon absorption. According to the different initial pH values, the optimal amount of desulfurized gypsum was calculated and the corresponding atmospheric CO2 absorption was obtained. With the initial pH increasing, it showed the trend of decreasing first and then increasing. The variation range of atmospheric CO2 absorption was 0.29 kg/m2-0.81kg/m2. The fitting formula was finally obtained by fitting (R2=0.96, P<0.05). (5) The relationship between environmental factors and atmospheric CO2 uptake was obtained through redundancy analysis (RDA). The results showed that the positive correlation order was: Amount of desulfurized gypsum addition > CO32-> K+ > soil moisture > SO42-, negative correlation The order is: initial pH > Cl- > Ca2+ > SAR > ESP > Na+ > pH > EC. |
| 中文关键词 | 盐碱土 ; 碳吸收 ; pH值 ; 土壤呼吸 ; 环境因子 |
| 英文关键词 | Saline-alkaline soil Carbon sequestration pH Soil respiration Environmental factors. |
| 语种 | 中文 |
| 国家 | 中国 |
| 来源学科分类 | 环境工程 |
| 来源机构 | 中国科学院新疆生态与地理研究所 |
| 资源类型 | 学位论文 |
| 条目标识符 | http://119.78.100.177/qdio/handle/2XILL650/288193 |
| 推荐引用方式 GB/T 7714 | 雒琼. 脱硫石膏改良碱土过程中大气CO2吸收强度研究[D]. 中国科学院大学,2018. |
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