Development of Biodegradable Binding Materials Synthesized from Co-Application of Byproducts Based on a Pyrolysis Polygeneration Process for Slow-Release Fertilizers

Abstract

The biochar-based slow-release fertilizers (BSRFs) are vital for the development of eco-friendly and sustainable agriculture. Considerable attentions have been attracted for enhancing efficiency of fertilizers (EEF) by appropriate modifying or binding to reduce nutrient waste and improve the slow-release effect in growth of plant. In this study, sustained binding materials was presented for BSRFs synthesis, including pyroligneous acids (PA), bio-oil (BO), and modified starch binder (MSB). The results showed that the release ratio of phosphorus from PA+BO+MSB was 4.7%, 15.2%, and 21.2% slower than that of sole binding with PA, BO, and MSB, respectively. The BSRFs were characterized by SEM, XRD, FT-IR, XPS, EDS and the release kinetic outcome revealed that the PA+BO+MSB contributed to a satisfactory structure formed in BSRFs. The viscosities of the MSB significantly influenced the slow-release performance and accumulation of N, P, and K nutrients. Moreover, the PA+BO+MSB exhibited the lowest cost in the economic assessments.

Keywords: Pyroligneous acid, Rape, Photosynthesis, Ritger−Peppas model, Economic assessments