The Desalting Dynamics of Clayey Saline Dredger Fill After Efficiency Improvement with Straw Treatment

Zhang Bo;Ma Lvyi;Duan Jie;Li Jia;Wang Wei;Liu Hongqing;College of Forestry,Beijing Forestry University;National Energy R&D Center for Non-food Biomass/Beijing Forestry University;Hailin Tianjin Horticulture Environmental Science and Technology Engineering Co.,Ltd.;

clayey saline dredger fill;;desalting dynamics;;alkalization;;improvement technology;;laboratory lysimeter

In order to develop a sound saline soil improvement technique and find its application effects, the author introduced lysimeter column test, in which desalting dynamics in clayey saline dredger fill columns treated with straw mixture, straw column and straw layer and the CK column were observed respectively under the condition of continuous water leaching. The results showed that: compared with the CK column, the former could remarkably improve soil permeability and water desalting rate and constrain salt accumulation and resalinization. Moreover, it could shorten desalting time and save over 60% fresh water. Soil alkalization was obviously observed in the CK column, while it was not the case in improvement column as big pores were formed by straw and flue gas desulfurization gypsum was added. Both organic matter and nitrogen content were reduced in the control column, but they were increased in improvement column after the straw was added. Those findings indicate that this technique could effectively reduce water usage, increase desalting rate, curb soil alkalization and shorten desalting time in improving clayey saline dredger fill.