Barbi Silvia, Barbieri Francesco, Andreola Fernanda, Lancellotti Isabella, Barbieri Luisa, Montorsi Monia
Department of Science and Methods for Engineering, University of Modena and Reggio Emilia, Via Amendola 2, 42122 Reggio Emilia, Italy.
Interdepartmental center for applied research and services in advanced mechanics and motoring, INTERMECH-Mo.Re., University of Modena and Reggio Emilia, Via P. Vivarelli 10/1, 41125 Modena, Italy.
ACS Omega. 2020 Oct 16;5(42):27154-27163. doi: 10.1021/acsomega.0c03082. eCollection 2020 Oct 27.
In this study, an organic nitrogen-based coating was developed based on black soldier fly (BSF) prepupae reared on poultry dejections and deposited on ceramic lightweight aggregates (LWAs), containing phosphorous (P) and potassium (K) from agroresidues, leading to a complete nitrogen, phosphorus, and potassium (NPK) fertilizer. To obtain a resistant coating with good adhesion to LWAs, different plasticizing agents were tested (e.g., glycerol, cellulose, and polyethylene glycol). The coating formulation was optimized through a design-of-experiment (DoE) approach to correlate the effect of each mixture component on the coating's performance. BSF biomass was characterized through chemical and thermal routes, as well as the final coated LWAs, confirming their general agreement to fertilizer's requirements. Release tests in static conditions highlighted the barrier action of the coating, preventing uncontrolled release of potassium and phosphorus contained in the LWAs as well as the release of nitrogen after 21 days (near to 20%). Germination and growth tests indicated a valuable increase of the growth index, whereas the germination process is limited by the coating barrier effect. This work proposes a new product in the field of slow-release fertilizers designed by rational methodologies and innovative materials based on waste valorization, fully in agreement with a circular economy perspective.
在本研究中，基于以家禽粪便饲养的黑水虻预蛹开发了一种有机氮基涂层，并将其沉积在含有来自农业废弃物的磷（P）和钾（K）的陶瓷轻质骨料（LWA）上，从而制成了一种完整的氮磷钾（NPK）肥料。为了获得对LWA具有良好附着力的抗性涂层，测试了不同的增塑剂（例如甘油、纤维素和聚乙二醇）。通过实验设计（DoE）方法优化了涂层配方，以关联每种混合物成分对涂层性能的影响。通过化学和热学途径对黑水虻生物质以及最终的涂层LWA进行了表征，证实它们总体上符合肥料的要求。静态条件下的释放测试突出了涂层的阻隔作用，可防止LWA中所含钾和磷的不受控制释放以及21天后氮的释放（接近20%）。发芽和生长测试表明生长指数有显著提高，而发芽过程受到涂层阻隔作用的限制。这项工作提出了一种缓释肥料领域的新产品，该产品由基于废物 valorization 的合理方法和创新材料设计而成，完全符合循环经济的理念。
