【作者】 王星；

【导师】 吕家珑；

【作者基本信息】 西北农林科技大学 ， 土壤学， 2003， 硕士

【摘要】 采用热分析和红外光谱法分析一种普通地膜和三种可降解地膜的组成和降解性能。采用微生物培养法检验生物降解膜的可降解性。采用田间试验和盆栽试验研究可降解地膜对作物生长和土壤环境的影响。 热分析的结果表明，四种地膜的差热曲线有许多相似，但也略有差异，说明降解膜与普通膜的基本组分相同，而添加组分有较大差异。地膜在热解时极大熔融吸热峰处的反应级数约为0.93。各地膜热解的活化能和指前因子的大小顺序为；普通膜＞光降解膜＞生-光双降解膜＞生物降解膜。覆膜后，地膜试期降解样的差热曲线与原样基本相同，但降解样的极大熔融吸热峰温度比原样稍微增高，极大熔融吸热峰处的反应级数有所下降，普通膜的活化能略有降低，光降解膜的活化能降低较为明显，相反，生物降解膜和生-光双降解膜的活化能略有升高。从热重曲线可以测算，生物膜中淀粉的含量约为21.05％，生-光双降解膜中碳酸钙含量约为10.91％。地膜试期降解样的热重曲线和微分热重曲线与原样基本相同，但极大失重峰的温度比原样略有提高。生物降解膜试期降解样中淀粉的含量和生-光双降解膜试期降解样中碳酸钙的含量均有所减少。研究结果还表明，差热分析和热重分析是分析地膜的组成，研究其热解特性，评价其降解性能的一种简便而有效的方法。地膜热解活化能可作为地膜降解性能强弱的判据，地膜DTA曲线及DTG曲线的特征峰可作为辨别生物降解膜及生-光双降解膜的依据。 红外光谱分析结果表明，不同类型地膜的红外光谱不同，红外光谱可作为普通膜与降解膜，以及不同类型降解膜之间的鉴别手段。地膜覆盖一定时期的降解膜样品的红外光谱可显示出地膜组分和性状的一些变化，可作为判断地膜降解状况的依据。羰基指数可作为评价地膜降解状况的指标。三种降解膜原样的羰基指数大小顺序为：生物降解膜＞生-光双降解膜＞光降解膜。 微生物培养的结果表明，加混合孢子悬液的生物降解膜降解率比未加的生物降解膜高，加土壤悬液的生物降解膜降解率比未加的生物降解膜高。不同培养基比较，生物降解膜降解率的大小顺序为：细菌培养基＞放线菌培养基＞真菌培养基。加大田土悬液的生物降解膜降解率最大。生物降解膜的降解率远大于普通膜。液体培养法做检验试验的结果表明，混和菌有助于生物降解膜的降解；液体培养中生物降解膜的降解率大于固体培养。 地膜覆盖种植玉米的结果表明，地膜覆盖在玉米生育中期保水效果明显，而在生育前期和后期保水效果不明显。在生育中期保温效果不明显，而在生育前期和后期保温效果明显。降解膜和普通膜的保水、保温和增产效果基本相同。各降解膜对玉米生长和土壤环境的影响无差异。三种降解膜的降解速率为：生物降解膜＞生-光双降解膜＞光降解膜。播种前各处理的养分含量基本相同，全生育期中覆膜处理的养分含量总体上高于对照，各覆膜处理之间差异不明显，到收获时各处理的养分状况又趋于相同。 盆栽试验的结果表明，各处理间的差异均不显著，即不同的地膜种类、残留量和残膜面积对盆栽玉米的生长都没有显著影响。更多还原

【Abstract】 The components and degradabilities of one kind of ordinary film and three kinds of degradable films were analysized by thermal analysis and infrared spectroscopy.Biodegradable film’s degradability was tested by micro-organism culture.Degradable films’ effects on com growth and soil environment were studied by field experiment and pot experiment.The results of thermal analysis showed that the DTA curves of four kinds of films had much similarity and seldom difference,which meant that degradable films had more same components as ordinary film,but their added components were very different.Films’ pyrolysis reaction orders in maximum melting endothermic peak were about 0.93.The order of films pyrolysis’s activation energies and anaphoric factors was:ordinary film>photodegradable film>bio-photodegradable film>biodegradable film.After films being mulched,the DTA curves of degradated films in test were as same as those of original films on the whole.The degradated films’ temperature in maximum melting endothermic peak were higher than original films’.The degradated films’ pyrolysis reaction orders in maximum melting endothermic peak were smaller than original films’.Ordinary film’s pyrolysis’s activation energy was decreased a little,photodegradable film’s pyrolysis’s activation energy was decreased more,by contrastjbiodegradable film and bio-photodegradable film’s pyrolysis’s activation energies were increased a little.Calculation from thermogravimetric curves showed that the content of starch in biodegradable film was about 21.05% and the content of calcium carbonate in bio-photodegradable film was about 10.91%.The thermogravimetric curves and differential thermogravimetric curves of degradated films in test was as same as those of the original films.The content of starch in biodegradable film and the content of calcium carbonate in bio-photodegradable film were all decreased.The results were also showed that differential thermal analysis and thermogravimetric were a simple and efficient methold to analysize films’ components,study their pyrolysis characters and assess their degradabilities.Film’s degradability can be judged by film’s pyrolysis’s activation energy.Biodegradable film and bio-photodegradable film can be differentiated by DTA curve and DTG curve’s character peaks.Analysis of infrared spectroscopy showed that different kinds of film had their own infrared spectrum,ordinary film and degradable film can be differentiated by infrared spectrum,so did different degradable films.The infrared spectrum of mulched film for a certain period can show some changes of film’s components and characters,which can be used to judged the state of film’s degradation.Carbonyl index can be used as an quota to judge the state of film’s degradation.The order of three kinds of degradable film’s carbonyl indexes is:biodegradable film>bio-photodegradablefilm>photodegradable.The results of micro-organism culture showed that the degradable rate of the biodegradable film added with spore suspension was higher than that of the biodegradable film without spore suspension.The degradable rate of the biodegradable film added with soil suspension was higher than that of the biodegradable film without soil suspension. Compared different culture mediumSjthe order of degradable rates of the biodegradable films was:bacteria medium>actinomyces medium>fungi medium.The degradable rate of the biodegradable film with field soil suspension was the highest one.The degradable rate of biodegradable film was higher than that of ordinary film.The results of test under liquid culture showed that mixed bacterium were helpful to biodegradable film’s degradation;the degradable rate of biodegradable film under liquid culture was higher than that of solid culture.The results of planting corn by mulching film showed that film mulching had obvious effect on soil water conservation at the middle stage of corn growth,but at the earlier and later stages this effect was not obvious.Film mulching had no obvious effect on raising soil temperature at the更多还原