Agronomic potential value of household urban solid wastes by composting and composts quality assessment

ISSN: 2224-0616 Int. J. Agril. Res. Innov. Tech. 9(2): 1-8, December 2019 DOI: https://doi.org/10.3329/ijarit.v9i2.45403 Available online at http://ijarit.webs.com https://www.banglajol.info/index.php/IJARIT AGRONOMIC POTENTIAL VALUE OF HOUSEHOLD URBAN SOLID WASTES BY COMPOSTING AND COMPOSTS QUALITY ASSESSMENT K.K.A. Alate1, G. Mawussi1*, K.D. Ayisah2 and K. Sanda1 Received 28 June 2019, Revised 20 November 2019, Accepted 24 December 2019, Published online 31 December 2019 Abstract Using composting technology, the biodegradable fraction of solid wastes collected from Agbalepedogan district in Lomé (Togo) was transformed into composts with no phytotoxicity suitable for use in agriculture. The household urban solid wastes were mixed with poultry manure and Mucuna pruriens leaves in appropriate percentages and transformed into composts. The composting process was monitored by temperature, pH and C/N ratio controlling. The composts quality was appreciated by phytotoxicity test, particle size distribution, contents of nitrogen, phosphorus, potassium, organic matter and trace elements. The results showed that composts particle size distribution presented four fractions (>10 mm, 5-10 mm, 2-5 mm and ≤2 mm) whose average percentages are respectively 9.04±0.2%; 10.71±0.2%; 12.68±0.4% and 67.53±0.6%, respectively. Composts produced contained 1.02±0.1% - 2.72±0.2% of nitrogen, 1.35±0.3% - 2.70±0.4% of phosphorus, 1.31±0.2% - 1.72±0.3% of potassium and 23.50±0.4% - 37.75±0.5% of organic matter. The pH in final composts were between 8.50±0.2 and 9.00±0.3 while C/N ratio varying from 8.06±0.2 to 13.13±0.2. The concentrations of some heavy metals in final products were 79.8±1.7 - 140.2±1.6 mg/kg.dm of zinc, 27.1±1.01 - 76.6±1.03 mg/kg.dm of copper, 2.07±0.33 - 9.19±0.22 mg/kg.dm of lead, 4.13±0.16 - 11.05±0.36 mg/kg.dm of nickel and 0.79±0.02 - 2.15±0.03 mg/kg.dm of cadmium. These concentrations were lower than the limited value for heavy metals prescribed by French and US EPA regulation for organic and organic-mineral fertilizers. Keywords: Household Solid Waste, Poultry Manure, Mucuna pruriens, Composting, Composts Quality. 1 Department of Soil Sciences, Research Laboratory on Agroresources and Environmental Health, School of Agronomy, University of Lome, BP 1515 Lome, Togo. 2 Department of Plant Science and Improvement, School of Agronomy, University of Lome, BP 1515 Lome, Togo. *Corresponding author’s email: (G. Mawussi) Cite this article as: Alate, K.K.A., Mawussi, G., Ayisah, K.D. and Sanda, K. 2019. Agronomic potential value of household urban solid wastes by composting and composts quality assessment. Int. J. Agril. Res. Innov. Tech. 9(2): 1-8. DOI: 10.3329/ijarit.v9i2.45403. Introduction The production of urban solid waste is increasing in quantity and diversity in African developing countries and generates huge risks on the environment and the health of populations. The generation of household solid waste has been increasing in Lome, capital of Togo in West Africa, mainly driven by growing global population, urbanization and economic growth, coupled with changing activities and consumption behavior (Koledzi, 2011). A household urban waste is defined as a material whose economic value is zero or negative. In order to secure the ecological balance and an adequate living quality for the human society also in the future, it is more than ever before necessary to manage these wastes, utilize them to the extent possible to save primary resources. Waste management is a major challenge for any society. It contributes to sustained economic activity and enhances public welfare. In recent years, the research showed that, many wastes produced in important quantities may be transformed into an organic fertilizer by composting. Land application of compost obtained from municipal waste is one of the most economical and attractive methods of solving two problems in the developing countries: waste disposal and soil infertility. Therefore, composting is more suitable technology for waste management in developing countries. Compost consists of the relatively stable decomposed organic materials resulting from the accelerated biological degradation of organic materials under controlled and aerobic conditions. Many studies (Ouédraogo et al., 2001; Caravaca et al., 2003; Gamal, 2009) have shown that application of mature composts at reasonable rates improves soil physical properties, increases available soil nutrient levels and plant growth. International Journal of Agricultural Research Innovation & Technology 1 Alate et al. (2019) Agronomic potential value of household urban solid wastes by composting The aim of this study is to assess the agronomic potential value of biodegradable fraction of household urban solid waste collected from Agbalepedogan district in Lome (Togo) by composting, as well as to evaluate the quality of the final product composts. Materials and Methods The composting took place at a large-scale composting platform of the Non Governmental Organization: Clean Natural Ecosystem (ENPRO) situated in Lome (6°10'N, 1°11'E; with altitude comprises between 19 and 60 m). The household urban solid wastes collected from one district of Lome called Agbalepedogan were transferred to clean area and physically segregated into different inorganic and organic components (Fig. 1). They were sorted by the following categories: biodegradable fraction (wood and wood products, pulp, paper and cardboard, food, food waste, textiles, garden, yard and park waste) and no biodegradable fraction (glass, plastic, metal and other inert waste; fine and sand). The windrows produced respectively compost CW100, compost CW85P15, compost CW70P30, compost CW85M15 and compost CW70M30. Composting operation The windrows had triangular shape with 1.5 m wide of the base and 1.0 - 1.5 m high (Fig. 2). The windrows were turned using a loading shovel twice a week for the first 10 weeks (Fig. 3) and then, the material was allowed to mature for a period of 3 weeks with no turning. A representative sample of approximately 500 g was taken once a week after turning. The sample was a composite made up from 10 grab subsamples taken along the length on the windrow. The samples were screened through a 10 mm sieve and kept refrigerated for physicochemical analysis. The moisture was kept at 45 50% by adding water. The temperature was monitored daily using mercury thermometers placed near the centre of the pile at six different points along its length and the average of all measurements was recorded. Other parameters controlling are pH and C/N ratio. The composting process involved three phases: pilling (Fig. 2), compost maturation (Fig. 3) and compost screening (Fig. 4). Fig. 1. Physical segregation of household urban solid wastes into different inorganic and organic components. The urban solid waste biodegradable fraction characterized by high organic carbon and low nitrogen contents, is co-composted with poultry (...truncated)