https://doi.org/10.17113/ftb.63.02.25.8904

Article in press

Comparative Study on Composting and Vermicomposting for Digestate Physicochemical Enhancement via Kitchen Waste Addition

Ze Sen Tan¹, M. Devendran Manogaran^1,2, Rashid Shamsuddin^3*, Mohd Hakimi¹, Lee Wen Looi¹, Kai Tong Woo¹, Chin Seng Liew² and Lailatul Qomariyah⁴

¹Chemical Engineering Department, Faculty of Engineering, Universiti Teknologi PETRONAS, 32610 Seri Iskandar, Perak, Malaysia

²Centre of Carbon Capture, Utilisation and Storage, Institute of Sustainable Energy and Resources, Universiti Teknologi PETRONAS, 32610 Seri Iskandar, Perak, Malaysia

³Department of Chemical Engineering, Faculty of Engineering, Islamic University of Madinah, 42311 Madinah, Saudi Arabia

⁴Department of Industrial Chemical Engineering, Institut Teknologi Sepuluh Nopember, 60111 Surabaya, Indonesia

Copyright © 2024 This is a Diamond Open Access article published under CC-BY licence. Copyright remains with the authors, who grant third parties the unrestricted right to use, copy, distribute and reproduce the article as long as the original author(s) and source are acknowledged.

Article history:

Received: 5 October 2024

Accepted: 1 April 2025

Keywords:

conventional composting; vermicomposting; chicken manure digestate; kitchen waste; physicochemical enhancement; macronutrients enrichment

 The content of this publication has not been approved by the United Nations and does not reflect the views of the United Nations or its officials or Member States.

Summary:

Research background. The escalating growth in Malaysian population has resulted in the rise of kitchen waste generation, especially inedible organic kitchen waste, which is generally disposed to landfills and impacts the environment. Apart from that, the increasing demand for chicken products in Malaysia has led to a significant increase in chicken manure production, and with the anaerobic digestion being explored further, there is a concern in utilization of the chicken manure digestate. Hence, this research addresses the challenge of treating kitchen waste and chicken manure digestate in Malaysia by exploring the effectiveness of composting and vermicomposting methods via comparative analysis. With the integration of kitchen waste, specifically spent coffee grounds, bone waste, and used kitchen towel, this study aims to enhance the imbalanced physicochemical properties of chicken manure digestate.

Experimental approach. Before composting, characterisation of kitchen waste and chicken manure digestate was performed to investigate the initial physicochemical properties. Four composting setups comprising the substances were established to study the physical appearance, temperature and pH profile, enhancement of nitrogen, phosphorus and potassium content, and the mass reduction in the final compost upon 50-day composting.

Results and conclusions. The vermicompost with kitchen waste additives observed significant nutrient enhancement with an NPK ratio of 1:3.57:6.58 with lower moisture content of 48.92 %, requiring the shortest maturity duration (20 days), and highest mass reduction (55.11 %).

Novelty and scientific contribution. The novelty of this research highlights the valorisation of organic kitchen waste and chicken manure digestate as biofertilizers. The final output is achieved by promoting a sustainable alternative to accommodate kitchen waste besides a conventional waste-to-landfill approach, while addressing the pain point of digestate, primarily its imbalanced physicochemical properties, specifically its macronutrients, pH, and moisture content. In contrast to previous studies, the framework of this work investigates the effectiveness of both conventional composting and vermicomposting with the incorporation of organic kitchen waste, namely spent coffee grounds, bone meals, and used kitchen towels in enhancing the physicochemical properties of digestate.