The mechanisms of the Si-heavy metals interaction in the soil, from theory to practice

• 作 者: Vladimir Matychenkov Elena Bocharnikova Magne D(a)st(o)l Wei Xiao Zhan Qiang
• 机 构: DepartmentofEcologyandPhysiologyofAutotrophicOrganisms,InstituteBasicBiologicalProblems,Pushchino,Ru
• 出 处: The 17th International Conference on Heavy Metals in the Env
• 发表日期: 2014年9期
• 关键词: silicon pollution heavy metals soil

　　Heavy metal pollution of the cultivated area is one of the most actual problems today.It is available numerous data which has demonstrated that the application of the Si fertilizers or Si-rich soil amendment can reduce the mobility of the heavy metals,however the mechanism of this process is investigated very poor.Using of the standard and elaborated methods the interaction between active forms of Si(liquid and solid)with heavy metals(Cd,Pb,Ni,Cu)in soil-plant system was investigated.Laboratory,greenhouse and field tests were conducted in USA,Russia and in China.The application of active forms of Si initiated several types of the reaction with heavy metals – reaction of precipitation with monosilicic acid,formation of water-soluble complexes and chemical adsorption on Si-rich surface.The monosilicic acid is control heavy metals mobility in the soil solution.Low concentration of monosilicic acid initiated the formation of soluble complexes with heavy metals,which in result increase the mobility of heavy metals in soil.The greenhouse tests showed that low rate of Si fertilizers can increase the mobility of heavy metals on 30-150%.The high concentration of the monosilicic acid in soil solution can dramatically reduce(2-3 times)the heavy metals mobility and protect cultivated plants against pollution.The application of the solid forms of active Si reduces the heavy metals leaching on 30-80%.By this means using the different forms of Si and various rate of Si we can regulate the mobility,migration and transformation of the heavy metals in the soil-plant system.The theoretical investigations give possibility to increase the efficiency of applied Si fertilizers or Si-rich soil amendments for reduction of the heavy metals adsorption by cultivated plants.The content of mobile and potential mobile heavy metals in the soil was reduced under application of Si-rich materials on 10-50%and more.The greenhouse and field tests with different types of Si-rich substances showed that the effect on heavy metals mobility and on their adsorption by plants depend on rate of Si-rich materials and on the content of active Si in Si-rich substances.