【作者】 张延光；

【导师】 金永灿；

【作者基本信息】 南京林业大学 ， 环境工程， 2009， 硕士

【摘要】 本文以稻草汽爆浆为实验材料,研究汽爆稻草的成分和结构特征对其用于栽培基质的影响。主要研究结果如下:1.汽爆后的稻草,半纤维素含量降低明显,木质素和灰分含量变动不大, C/N和pH值降低,但电导率值过高,汽爆稻草含有丰富营养物质,无重金属污染。2.汽爆处理可以改善秸秆的物理性状,粉碎处理可增加汽爆浆的容重和总孔隙度,但也降低了通气孔隙和大小孔隙比。用汽爆浆改良砂土,混合基质的容重、孔隙、持水量均与汽爆浆含量呈显著线性相关。3.通过研究稻草汽爆浆溶出物对小白菜发芽影响,溶出物对提高小白菜的发芽势和发芽率有积极影响。在适宜的浓度条件下,小白菜鲜重和干重均有增加,溶出物对改善小白菜根冠比也有积极影响。4.对稻草汽爆浆水浸出液做离子分析,检测出K⁺、Ca²⁺、Mg²⁺和NH₄⁺阳离子,其中K⁺含量最高,NH₄⁺的含量最低。粉碎和打浆处理有利于无机盐的溶出。添加营养液后,增加的Ca²⁺、Mg²⁺会使K⁺、NH₄⁺的吸附率变低。Ca²⁺比Mg²⁺的吸附力更强,Ca²⁺甚至可以取代部分原来吸附Mg²⁺的点位。汽爆浆对阴离子的吸附并不牢固,浆液中带负电荷的可溶性有机物会降低阴离子的吸附量。更多还原

【Abstract】 With steam-exploded rice straw used as materials, the effect of composition and structure properties as growing substrate is investigated. The main results are listed as follows.1. By the treatment of steam-explosion, the content of hemicellulose in rice straw decreased greatly. The content of lignin and ash changed little. C/N ratios and pH value got lower, but EC value was higher. Steam explosion pulp was abundant in nutrient elements and without heavy metal pollutants.2. The physical properties of rice straw changed significantly after steam explosion treatment. With milling treatment bulk density and total porosity improved, but airspace and ratio of large and small pores decreased. Through utilizing steam-exploded rice straw to amend sandy soil, the bulk density, porosity and water holding capacity showed a good linear relationship with the content of steam-exploded rice straw.3. Bok choy （Brassica chinensis） was used to investigate the effects of the dissolved substrate of steam-exploded rice straw on seeds germination. A positive effect can be observed on promoting germination potential and germination rate. The total fresh and dry weight increase under suitable concentration. The releasing substance from steam-exploded rice straw is also beneficial to vegetable root/stem.4. According to the ion analysis of dissolved substance from steam-exploded rice straw, K⁺, Ca²⁺, Mg²⁺ and NH₄⁺ were detected, in which K+ was the highest, and NH₄⁺ was the lowest. Milling and refining had a positive effect on mineral substances releasing. Nutrient liquid being added, the increase of Ca²⁺ and Mg²⁺ lowers the adsorption efficiency of K⁺ and NH₄⁺. The adsorption ability of Ca²⁺ was stronger than Mg²⁺, and even part of the adsorption point of Mg²⁺ is replaced by Ca²⁺. The anions adsorption of steam-exploded pulp is not stable. The dissolved organic matter with negative charge decreases the quantity of anions adsorption.更多还原