鸡毛交联纤维素多功能锌肥制备与性能研究

Preparation and Properties of Multi-functional Zinc Fertilizer Made by Cross-linking Chicken Feathers and Cellulose

以鸡毛(CF)和纤维素(Cell)为原料,氢氧化钾/水/尿素(KOH/H2O/CO(NH2)2)体系为复合溶剂,碱解鸡毛得到鸡毛碱解液,然后向鸡毛碱解液加入纤维素形成凝胶化的混合物,为发挥凝胶基质中官能团的保肥作用向其内部加入微量元素Zn,经过干燥并造粒,最后得到含N(150.6 mg/g)、K(136.7 mg/g)、Zn(13.9 mg/g)并同时含有硫、多肽和氨基酸等营养成分的鸡毛交联纤维素凝胶肥料(Cell-CF)。利用红外光谱(FTIR)、X射线衍射(XRD)、X射线光电子能谱(XPS)、荧光显微镜对Cell-CF水凝胶的交联结构及形成机理进行分析与表征。结果表明:经复合溶剂处理后鸡毛和纤维素原料的结晶结构破坏较完全,Cell-CF中的多肽和纤维素进行了分子间的穿插折叠并形成了较强的分子间作用力,Cell-CF中的官能团与锌离子进行了络合反应。另外,土壤培养实验和玉米盆栽实验结果表明,Cell-CF中锌的生物有效性高、肥效期长,可作为一种长效锌肥。

The development of new fertilizers from agricultural and industrial wastes could be both environmentally-friendly and low-cost. High-value utilization of chicken feather（ CF） and cellulose（ Cell） has always been a challenging endeavor. A multi-functional zinc-rich fertilizer was developed by cross-linking CF and Cell with KOH/H2 O/CO（ NH2）2（ KOH,1. 5 mol/L; CO（ NH2）2,0. 12 g/m L）being a composite solvent,which was named Cell-CF. The main procedures were： the CF was firstly gone through alkaline hydrolysis in the composite solvent with ratio of solid to water of 1∶ 10 at temperature of75℃ for 2 h,then the polypeptide solution was obtained and cooled at-12℃; secondly,the Cell（ 0. 06 g/m L） was immersed into the polypeptide solution and the Cell-CF hydrogel was obtained after highintensity stirring for 30 min; thirdly,dilute H2 SO4 solution was used to adjust the p H value of Cell-CF gel to 6. 5; fourthly,Zn SO4·7 H2 O was added to the gel followed by constant stirring of 1 h; finally,the above gel was prilled with a 1 cm × 1 cm × 1 cm cubic mould and dried at 60℃ in oven. Chemical analyses of the granulated Cell-CF fertilizer showed that it contained nitrogen of 150. 6 mg/g,potassium of 136. 7 mg/g and zinc of 13. 9 mg/g. Water sorption measurement indicated that Cell-CF had good swelling capacity in water. Hydrostatic nutrients release experiment revealed that Cell-CF could slow down the release of potassium and zinc into water. The formation mechanism of cross-linking structure of Cell-CF was investigated by FTIR and X-ray. It was demonstrated that the crystal structures of CF and Cell were destroyed after being treated with the composite solvent, and there was hydrogen bond interaction between the polypeptide and Cell. After the Cell-CF was immersed into water for 8 h,strong fluorescence signal was detected from the crossed Cell-CF while there was no fluorescence around CellCF,meaning that the polypeptide was not dissolved in water and the molecular interactions between Celland CF were strong. Photoelectron spectroscopy results showed that zinc was chelated with the functional groups of Cell-CF. Soil incubation experiment and pot experiment showed that Cell-CF could release high bio-available zinc in a long term.