土壤中低相对分子质量聚乙烯(L-PE)的提取及其降解特性研究  

Study on Extraction Rates and Degradation Characteristics of Low Relative Molecular Weight Polyethylene (L-PE) in Potted-Soil

作　　者：韩娜[1] 张春惠[1] 卢红[1] 赖金龙 吴国[1] 陶宗娅[1] 

机构地区：[1]四川师范大学生命科学学院,四川成都610101

出　　处：《四川师范大学学报（自然科学版）》2017年第2期228-233,共6页Journal of Sichuan Normal University（Natural Science）

基　　金：国家核设施退役及放射性废物治理重点项目(14ZG6101);四川省教育厅自然科学重点基金(14ZA0030);地方高校国家级大学生创新创业训练计划项目(201610636090)

摘　　要：环境可降解地膜降解后形成大量低相对分子质量残体,这些低相对分子质量残留物累积在土壤耕作层,对土壤微环境及作物生长发育构成潜在危害.这些残留物可在土壤中进一步降解,但其降解进程尚不清楚.研究这类低相对分子质量残留物碎化降解和无机矿化进程,对进一步优化可降解地膜配方、生产工艺及提高可降解地膜的环境安全性具有重要的实践意义.选用相对分子质量分别为2 000(M1)、5 000(M2)和100 000以上(M3)的聚乙烯(L-PE),以不同累积量(1、10、50和100 a量)添加到不同质地(壤土、砂土、黏土)的土壤中,经盆栽种植一季小麦后,采用十氢萘高温融化法从土壤中提取L-PE,用凝胶渗透色谱法(GPC)检测L-PE相对分子质量及其分布的变化.结果显示,十氢萘高温融化法未改变L-PE的结构特征;L-PE相对分子质量大于5 000时,其提取率达74.47%~97.48%,提取率随相对分子质量增加而提高;经盆栽种植一季小麦后,添加到土壤中的3种相对分子质量的L-PE(M1、M2、M3)均发生了不同程度的降解,降解效果为M3>M1>M2.Biodegradable plastic mulch film was degraded to form a large number of relative low molecular weight residues,which were accumulated in plough horizon so much and had caused latent risk to the soil microenvironment and the growth and development of crop. These residues can be further degradation in soil,but they are not clear in the process of further degradation. The research on the process of fragmentation and biomineralization of the relative low molecular weight residues was of great practical significance for optimizing the formula and production technology of biodegradable plastic mulch film and for evaluating the environmental safety of the degradable mulch film. In the experiments,low relative molecular weight polyethylene（ L-PE） with different relative molecular weight of2 000（ M1）,5 000（ M2）,100 000 above（ M3） and different accumulation（1,10,50,100 year respectively） were added into pottedsoils with different soil texture（ loam,sandy soil and clay）,in which wheat were planted. When the wheat were ripe and harvested,L-PE was extracted from the soils by decahydronaphthalene,and the relative molecular weight and their distribution changes were detected by the method of the gel permeation chromatography（ GPC）. The results showed that the structure characteristics of L-PE was not obviously changed by the method of decahydronaphthalene and high temperature melting. When the relative molecular weight of L-PE were more than 5 000,the extraction rate were 74. 47% - 97. 48%,and the rates were greater as the increase of L-PE relative molecular weight. Experienced a growing season of wheat,L-PE（ M1,M2,M3） could be degraded in different degrees in the pottedsoils,the degradation effects was M3〉M1〉M2.

关 键 词：低相对分子质量聚乙烯(L-PE) 提取率 平均相对分子质量表征参数 

分 类 号：X53[环境科学与工程—环境工程]