KMS XINJIANG INSTITUTE OF ECOLOGY AND GEOGRAPHY，CAS
| 脱硫石膏改良碱土过程中大气 CO2吸收强度研究 | |
| 雒琼 | |
| Subtype | 硕士 |
| Thesis Advisor | 马健 |
| 2018-06-01 | |
| Degree Grantor | 中国科学院大学 |
| Place of Conferral | 新疆乌鲁木齐 |
| Degree Discipline | 工程硕士 |
| Keyword | 盐碱土 碳吸收 pH 值 土壤呼吸 环境因子 Saline-alkaline soil Carbon sequestration pH value Soil respiration Environmental factors |
| Abstract | 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； 脱硫石膏是燃煤电厂脱硫技术产生的工业废弃物， 在我国每年产量巨大且利用率较低， 这对环境造成大量污染； 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， 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。 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， 由此干旱区的盐碱土改良不仅能够改善盐碱现状， 还必然能够对吸收大气 CO2 有所贡献。 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 种土壤样品作为研究对象，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） 改良部分： 通过添加脱硫石膏改良碱土， 在 0-20 的改良层中土壤 pH值、 碱化度（ESP） 、 钠吸附比（SAR） 均得到了有效改善， 且降低程度与脱硫石膏添加量呈正相关关系， 在整个 0-60 cm 的土层深度中改良效果为 0-20 cm >20-40 cm > 40-60 cm； 另外从淋溶液中分析得到钠离子占阳离子比重的 90%以上， 证实钠离子在改良层中被有效置换且去除。（2） 碳吸收部分： 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； 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 0.29kg/m2-0.81kg/m2， 最终通过拟合得到拟合公式（R2=0.98， P<0.05） 。（3） 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， 脱硫石膏添加量与大气 CO2吸收量呈现明显正相关关系， 初始 pH 值与大气 CO2 吸收量呈现明显负相关性； 对相关性进行排序显示， 正相关性： 脱硫石膏添加量> CO32 -> K+ >土壤含水率> SO42-， 负相关性： 初始 pH 值> Cl- > Ca2+ >SAR > ESP > Na+ > 土壤 pH >土壤 EC。 |
| Other Abstract | As the world population continues to grow and the available land area decreasesgradually, saline-alkaline soil has become the more important land resource in landdevelopment and utilization. Flue gypsum desulphurization (FGD) gypsum is anindustrial waste of desulphurization technology in coal-fired power plant. In China,the annual production is huge and the utilization rate is low, which causes a lot ofpollution to the environment. At the same time, the global climate change caused byCO2-based greenhouse gases has become a hot issue in the worldwide. Soil carbonpool, as the largest carbon sink in terrestrial ecosystems and also the most closelylinked 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-usemeasure, will inevitably change the absorption mechanism and absorption rate of CO2in the geo-gas system. Due to its special climatic characteristics in arid area, soilsalinization has become a prominent problem restricting the agricultural developmentand ecological environment improvement in arid areas.Therefore, the improvement ofthe saline-alkaline soil in the arid area not only improves the saline-alkali status, butalso can certainly contribute to the absorption of atmospheric CO2. Therefore, thestudy can not only determined the contribution to reducing atmospheric CO2 in themode of agricultural sustainable development with improved alkaline earth in theregion, but also can contribute to the reduction of atmospheric CO2, providing a directand convenient way for resource recovery and reuse mode of power factory wasteFGD gypsum. This study can provides important data for our correct understanding ofthe issue of carbon sequestration in the arid region. It has far-reaching significance forus to recognize the role of promoting the improvement of regional ecologicalenvironment in the current background of climate change.In this study, five soil types with pH range of 8.5-10.5 in the arid region wereselected as the research object. Taking the simulated leaching method of indoor fillingsoil 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 andthe corresponding chemical analytical data. The atmospheric CO2 absorption intensityduring the improvement was quantified through the determination of organic carbonand inorganic carbon in soil and leaching solution. Finally, based on the above data,analysis of the relationship between environmental factors and atmospheric CO2absorption intensity. The results showed the following:(1) Improvements effect: Improvement of alkaline soil by adding Flue gasdesulfurizated gypsum, soil pH, alkalinity (ESP), and sodium adsorption ratio (SAR)have been effectively improved in the 0-20 improved layer. The degree of reductionwas positively correlated with the amount of desulfurized gypsum, and theimprovement effect was 0-20 cm> 20-40 cm> 40-60 cm throughout the depth of 0-60cm. In addition, with the result of sodium ions accounted for more than 90% of thecation specific gravity in the elution solution, it was confirmed that the sodium ionswere effectively replaced and removed in the modified layer.(2) Through measuring the CO2 flux change, it can be confirmed that there is anatmospheric CO2 absorption process during desalination gypsum improvement ofsaline-alkaline soil. The whole process is divided into three stages, a reaction stage ofabout 0-12 days, a stable stage of about 12-18 days, and a natural fluctuation stageafter 18 days. Calculate the atmospheric CO2 absorption intensity of different initialpH 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 notproportional to the carbon absorption. According to the different initial pH values, theoptimal amount of desulfurized gypsum was calculated and the correspondingatmospheric CO2 absorption was obtained. With the initial pH increasing, it showedthe trend of decreasing first and then increasing. The variation range of atmosphericCO2 absorption was 0.29 kg/m2-0.81kg/m2. The fitting formula was finally obtainedby fitting (R2=0.96, P<0.05).(3) The relationship between environmental factors and atmospheric CO2 uptakewas obtained through redundancy analysis (RDA). The results showed that there wasa significant positive correlation between the amount of desulfurized gypsum and atmospheric CO2 absorption, and the initial pH was negatively correlated withatmospheric CO2 absorption. Sort the correlations and show a positive correlation:Amount of desulfurized gypsum addition > CO32-> K+ > soil moisture > SO42-,negative correlation: initial pH > Cl- > Ca2+ > SAR > ESP > Na+ > soil pH > soil EC. |
| Subject Area | 环境工程 |
| Language | 中文 |
| Document Type | 学位论文 |
| Identifier | http://ir.xjlas.org/handle/365004/14978 |
| Collection | 研究系统_荒漠环境研究室 |
| Affiliation | 中国科学院新疆生态与地理研究所 |
| First Author Affilication | 中国科学院新疆生态与地理研究所 |
| Recommended Citation 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]. 新疆乌鲁木齐. 中国科学院大学,2018. |
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