加氧微咸水溶氧量对土壤水盐运移特征的影响

利用微纳米发泡器对微咸水进行加氧处理,并对加氧微咸水入渗条件下的土壤水盐运移特征及对入渗模型参数影响开展了研究。结果表明,在微咸水不同溶氧量入渗条件下,入渗时间相同时,累积入渗量和湿润锋深度随溶氧量增加先增加后减小,微咸水溶氧量为14. 0 mg/L时累积入渗量和湿润锋深度最大。相比于其他处理,微咸水溶氧量为14. 0 mg/L时能加快水分入渗,增加土壤体积含水率。此外,相比于不加氧处理,不同加氧水平入渗均能提高灌溉水脱盐效率。同时,利用现有入渗模型对入渗过程进行了定量分析,结果显示代数模型和PHILIP模型都能准确描述加氧微咸水入渗过程,而且模型参数与微咸水溶氧量存在函数关系。PHILIP模型中吸渗率随着微咸水溶氧量的增加呈先增加后减小的趋势,最大值出现在14. 0 mg/L,代数模型中综合形状系数则呈现相反的规律,最小值出现在14. 0 mg/L,且代数模型可较好描述加氧微咸水一维垂直入渗条件下的土壤含水率分布。

Effect of Dissolved Oxygen Content of Oxygenated Brackish Water on Soil Water and Salt Transport

The distribution of salt and water and the parameters of infiltration model under the condition of oxygenated brackish water were investigated, and micro-nanobubble rapid generation device was used to carry out different oxygenated levels treatment to brackish water. The results showed that under the condition of different dissolved oxygen infiltration in brackish water, when the infiltration time was the same, the cumulative infiltration and the wetting front depth were increased first and then decreased with the dissolved oxygen amount, and when the dissolved oxygen content of brackish water was 14.0mg/L, the cumulative infiltration and the depth of wet front were maximum. Compared with other treatments, infiltration conditions with dissolved oxygen content of 14.0mg/L in brackish water could accelerate water infiltration and increase soil moisture content. In addition, compared with the treatment without the addition of oxygen, infiltration of different oxygen levels could improve the desalination efficiency of irrigation water. The fitting effect of algebraic model was better than that of PHILIP model under the condition of oxygenated brackish water. In the PHILIP model, with the increase of dissolved oxygen in brackish water, the permeation rate was increased first and then decreased, and the maximum appeared at 14.0mg/L. In the algebraic model, the comprehensive shape factor showed the opposite law, and the minimum value appeared at 14.0mg/L, the algebraic model was able to fit the soil moisture content under one-dimensional vertical infiltration conditions of oxygenated brackish water.