液化废纸包膜控释肥的制备及其在油菜上的应用

发布时间：2018-01-29 11:21

  本文关键词： 废纸 液化 包膜控释肥 油菜盆栽 降解　出处：《山东农业大学》2017年硕士论文　论文类型：学位论文

【摘要】：相对于传统水溶性化学肥料,包膜控释肥能够显著提高肥料的利用率,降低肥料淋溶带来的环境问题。但控释肥的高成本以及包膜材料的难降解是阻碍控释肥应用推广的重要因素。因此,针对上述两大重要问题,降低包膜控释肥的成本、选择可生物降解的包膜材料成为新型肥料研制的热点。利用生活中广泛存在的天然高分子如废纸、秸秆等制备生物基可降解高分子包膜材料,包膜后的控释肥具有优异的控释性能,且包膜材料具有低成本、生态环保等优点。因此,本文选用废纸作为主要原料,对液化方案进行优化,制备了液化废纸包膜材料,并通过转鼓包膜工艺制得了液化废纸包膜控释肥。通过红外光谱、热重分析、扫描电镜对液化物、膜材料的性能及微观结构进行了研究,通过静水浸提实验研究了控释肥料的养分释放性能及机理;采用盆栽试验观察了控释肥的施入以及残膜残留对油菜的生长发育和土壤的影响并研究了残膜的降解机理。主要研究结果如下:(1)单因素优化试验得出液化条件:液固比为10:1(溶剂:废纸,w/w)、溶剂比为2:8(EG:EC,w/w)、液化时间为1.5 h、液化温度为160℃、催化剂用量为液化剂的3%(w/w),在此条件下,废纸的液化率最高。同时在25℃静水浸提方式下评价了包膜控释肥的养分释放性能。研究发现,在最优条件下得到的包膜控释肥的控释效果最好,且养分释放期为84天。(2)通过废纸、液化物、聚多异氰酸酯、聚氨酯的FTIR分析可知,废纸在液化过程中发生了分解,并与液化剂发生反应生成了废纸多元醇。聚氨酯上NCO基团的消失表明废纸液化物上的OH和聚多异氰酸酯上的NCO发生反应合成了聚氨酯。(3)对控释肥包膜材料进行表征,研究了废纸液化物中羟基值与异氰酸酯基的不同摩尔比对膜材料性能的影响。研究发现,当[OH]/[NCO]摩尔比为1.05:1时,所得包膜材料性能最佳。从PCU的SEM电镜照片可以看出膜壳与尿素接触紧密,包膜材料表面均匀光滑、结构致密,膜断面几乎看不见任何微孔和裂纹。(4)通过包膜厚度对控释肥的养分释放性能的影响研究发现,当包膜率为3%时,控释肥的养分释放曲线呈倒“L”型,养分释放较快,释放期较短。当包膜率达到7%时,肥料的养分释放期为84天,养分释放曲线呈“S”型,与植物的生长曲线相一致。(5)通过土埋降解试验分别对土埋6和12个月的残膜降解情况进行了研究。发现土埋后的包膜材料发生了降解,且随着时间的延长降解趋势更加明显。(6)采用油菜盆栽试验,研究了控释肥的施入以及残膜残留对油菜生长及品质和土壤的影响。通过试验对比可以看出,控释肥与残膜的施入不仅提高了油菜的产量、改善了油菜的品质,还对改善土壤性质有一定的促进作用。
[Abstract]:Compared with the traditional water-soluble chemical fertilizer, coated controlled-release fertilizer can significantly improve the fertilizer efficiency. Reducing the environmental problems caused by fertilizer leaching, but the high cost of controlled-release fertilizer and the difficult degradation of coated material are the important factors that hinder the application and popularization of CRF. Reducing the cost of coated controlled-release fertilizer and selecting biodegradable coated material has become a hot spot in the development of new fertilizer. Biodegradable polymeric coating materials were prepared by straw. The coated controlled release fertilizer has excellent controlled-release properties, and the coating material has the advantages of low cost, ecological environmental protection and so on. In this paper, waste paper was selected as the main raw material, the liquefaction scheme was optimized, the liquid waste paper coating material was prepared, and the liquid waste paper coated controlled-release fertilizer was prepared by the rotary drum coating process. The infrared spectrum and thermogravimetric analysis were used to prepare the liquid waste paper coating controlled release fertilizer. The properties and microstructure of liquefaction and membrane materials were studied by SEM. The nutrient release performance and mechanism of controlled-release fertilizer were studied by hydrostatic extraction. Pot experiment was conducted to observe the effects of controlled release fertilizer application and residual film residues on the growth and development of rape and the degradation mechanism of residual film. The main results were as follows: 1). Single factor optimization test obtained liquefaction conditions: liquid-solid ratio is 10: 1 (solvent: waste paper). W / w, the solvent ratio is 2: 8 EGW / w / w, the liquefaction time is 1.5 h, the liquefaction temperature is 160 鈩，

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