Dairy Wastewater for Production of Chelated Biodegradable Zn Micronutrient Fertilizers.

Zinc contg. org. materials were synthesized using dairy wastewater and solid zinc waste derived from zinc nitrate with the goal of obtaining biodegradable, slow release, micronutrient contg. fertilizers. The developed synthesis procedure involved heating at mild 55 °C temp., followed by pH adjustment to 7, pptn., and drying. The resulting solid materials were characterized using wt. anal., thermogravimetric anal. (TGA), X-ray diffraction (XRD), and Fourier transformed IR spectroscopy (FTIR). Higher wastewater-to-zinc nitrate ratios of 1:1/5 yielded amorphous materials with no inorg. zinc compds. detected. TGA anal. showed very complex thermal behavior due to the large amt. of orgs. present while FTIR anal. suggested the presence of both coordinated and uncoordinated carboxylic acid and ester groups. The developed process can have a variety of applications in recovering Zn from waste sources, such as tire crumb, while returning this valuable micronutrient into soil as a slow release biodegradable fertilizer. [on SciFinder(R)]