Differentiation of the composting stages of green waste using the CIELAB color model

Abstract

BACKGROUNDCIELAB color variables can be used to monitor a composting process and evaluate the maturity of the compost with a new, rapid, easy, and low‐cost colorimetric analysis. However, to date there are no available data to support the ability of CIELAB color changes to depict the different stages of a composting procedure. This study aims to examine the correlation of CIELAB color variables with composting time to elucidate how color changes can be used to detect the different stages of a composting process. Two green waste industrial scale composting processes with different added materials were monitored using typical physicochemical and CIELAB color analyses.RESULTSDuring composting, color variables a*, b*, C*, and ΔΕ* exhibited fluctuations following a constant variation trend that correlated with each composting phase. This behavior depicts the transformation of the organic composition of compost, as described by Organic Carbon (OC), Carbon‐to‐Nitrogen ratio (C/N), Humic Acids (HA), and Fulvic Acids (FA). Moreover, color variables a*, b*, and C* showed strong relationships with OC, C/N, and HA/FA (R2 > 0.83) and with HA (R2 > 0.74). These results indicate that CIELAB color change follows the same general pattern for each composting procedure that utilizes the same main composting substrate, regardless of any differing additional materials.CONCLUSIONMonitoring the CIELAB color variables made it possible to depict the different phases of composting, especially the transformation of the organic composition of the compost. Accurately monitoring CIELAB color variables distinguishes the different stages of a composting process through a rapid analysis at radically reduced costs compared to complex physicochemical analyses. © 2023 The Authors. Journal of Chemical Technology and Biotechnology published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry (SCI).

Development of a novel green waste compost stability monitoring method using the CIELAB color model

“…In addition, the study by Tsivas et al (2023) showed that compost color had almost similar values and identical progression patterns when composting similar main organic substrates with different additives. However, the color variables appear to be influenced by the inherent properties of the raw materials (Tsivas et al 2023). In particular, different composting substrates exhibit different color values during composting (Khan et al 2009;Tsivas et al 2021).…”

“…Recent studies (Khan et al 2009;Tsivas et al 2021;Tsivas et al 2023) have shown that compost color, and in particular the CIELAB color model, could partially mitigate typical compost physicochemical analyses and provide a rapid and more cost-effective method for monitoring composting. Compost color change has been shown to follow the evolution of composting (Khan et al 2009;Tsivas et al 2021), and, in particular, organic matter transformation (Tsivas et al 2023).…”

“…Recent studies (Khan et al 2009;Tsivas et al 2021;Tsivas et al 2023) have shown that compost color, and in particular the CIELAB color model, could partially mitigate typical compost physicochemical analyses and provide a rapid and more cost-effective method for monitoring composting. Compost color change has been shown to follow the evolution of composting (Khan et al 2009;Tsivas et al 2021), and, in particular, organic matter transformation (Tsivas et al 2023). In certain cases, and particularly when the composting phases are sequential (Tsivas et al 2023) and do not merge (Khan et al 2009;Tsivas et al 2021), the color of compost appeared to be able to distinguish the different phases of composting.…”

“…Compost color change has been shown to follow the evolution of composting (Khan et al 2009;Tsivas et al 2021), and, in particular, organic matter transformation (Tsivas et al 2023). In certain cases, and particularly when the composting phases are sequential (Tsivas et al 2023) and do not merge (Khan et al 2009;Tsivas et al 2021), the color of compost appeared to be able to distinguish the different phases of composting. In addition, the study by Tsivas et al (2023) showed that compost color had almost similar values and identical progression patterns when composting similar main organic substrates with different additives.…”

“…In certain cases, and particularly when the composting phases are sequential (Tsivas et al 2023) and do not merge (Khan et al 2009;Tsivas et al 2021), the color of compost appeared to be able to distinguish the different phases of composting. In addition, the study by Tsivas et al (2023) showed that compost color had almost similar values and identical progression patterns when composting similar main organic substrates with different additives. However, the color variables appear to be influenced by the inherent properties of the raw materials (Tsivas et al 2023).…”