【作者】 张桥；

【导师】 伍钧； 张万钧； 李登煜；

【作者基本信息】 四川农业大学 ， 土壤学， 2003， 硕士

【摘要】 本文主要从施工方便性这个角度出发，研究利用滨海地区大量存在的海湾泥、碱渣、粉煤灰三种废弃物相混和来配制绿化种植土，采用室内模拟淋洗脱盐实验，应用脱盐速率、用水量、SAR、RSC、pH等指标筛选出具有较快的脱盐速率，较经济的脱盐淋洗用水量，达到脱盐标准时各盐渍性状满足植物生存要求，在脱盐过程中不存在碱化问题，脱盐后配比pH不会上升，含有的离子浓度对植物的生长不产生毒害作用，也不存在重金属污染的三种废弃物的最佳混合比例。试验结果表明，海湾泥：碱渣：粉煤灰=X₇：Y₇：Z₇（体积比）的混合比例是配制绿化种植基质的最佳配比。 室内淋洗模拟脱盐实验表明：在水分入渗条件下，随着盐分含量下降，该配比中Na⁺、Cl^-、SO₄^2-、K⁺、Mg²⁺、Ca²⁺的绝对含量都逐渐减少，HCO₃^-逐渐增加；Na⁺、Cl^-的相对含量逐渐下降，而SO₄^2-、K⁺、Mg²⁺特别是Ca²⁺、HCO₃^-的相对含量逐渐增加，当土壤含盐量下降到小于1g/kg时结果更加明显。淋洗过程中Na⁺、Cl^-离子下降速度最快，Na⁺、Cl^-浓度变化与全盐含量变化均呈极显著正相关(r=0.999^**)。淋洗结束时该配比盐分的化学类型由Na⁺—Cl^-型转变到HCO₃^-—Ca²⁺型，SAR变化与全盐含量变化呈显著的正相关（r=0.99^*），RSC变化与全盐含量变化呈显著的负相关（r=0.99^*）。 在积水入渗条件下，该配比剖面的水盐动态可划分为三个阶段，即表层脱盐阶段、盐峰下移阶段和底土脱盐阶段。上部土体的脱盐速度快于底部土体，20cm层次达到脱盐标准需要2天，而140cm土层则需要18天，淋洗过程中该配比的水盐运动速度主要取决于淋洗入渗水量，入渗水量越多，脱盐深度越大，入渗水量与脱盐深度呈显著正相关（r=0.97^*）。使得140cm土层达到脱盐标准（全盐含量＜3g/kg土）的用水定额是0.84ml/cm`3土。利用土柱一维水盐运移基本方程，采用Laplace变换，算出单位体积最佳配比脱盐理论用水量，计算结果与试验观测结果基本一致。更多还原

【Abstract】 On the base of construction convenience, the research utilizes the benthal mud, coal ash and alkali dreg, which abound in Tianjin Economy Technology Development Area, to mix the three solid wastes together to a new type of soil for landscaping. The best mixing proportion that Benthal mud : Alkali dreg : coal ash =X7 : Y7 : Z7( by volume) has been choosed out by indoor washing desalination experiment. The treatment has faster desalination speed, economic desalination water quota, and when it reached desalination standard, the salining properties is satisfy to plants surviving, it will not become alkali soil in the course of desalination, the pH didn’t raised after the desalination, after the desalination, the density of ion contained in the treatment hasn’t poison to the growth of plant, There hasn’t heavy metal polluted either. The treatment may be used as gardening soil after desalination and fertilization.The indoor simulate desalination experiment showed, the absolute content of Na +, Cl, SO42-, K+, Mg2+, Ca2+ in the treatment reduced and HCO3- raised along with the desalination process, the opposite content of Na+, Cl-reduced and SO42-, K + , Mg2+, Ca2+, HCO3- raised long with the desalination process, the treatment salinity type from Na+-Cl- become to HCO3--Ca2+ after desalination. The content variety of Na+ and Cl- has marked correlation with the total salt content variety.Under the condition of accumulation water leaching process, the water salt movement trend of the section can be divided into three stages, the desalination stage of top layer, the desalination stage of salt peak move down and the desalination stage of bottom layer. The soil desalination depth depend on washing water amount, the more water used, the depther soil layer zhas been desalinated. The water quota is 0.84 ml/cm3soil, which can make 140cm soil layer reach desalination standard.更多还原