Seasonal variation in solid waste composition and characteristics in a newly formed semi-urban municipality of Nepal

Abstract

An important aspect of municipal solid waste management is analyzing waste stream characteristics, which allows the selection of the appropriate waste management approach for various waste types. This study focuses on finding out the general seasonal variation (summer and winter) in the composition, characteristics, and energy value of municipal solid waste (MSW) in Nepal. A waste generation survey was conducted on 53 households (covering a population of 393 in summer and 388 in winter, determined as a statistically significant sample size), 3 schools, and 2 commercial restaurants in Godawari municipality. The study observed that household solid waste generation was 0.164 kg per capita per day in summer, compared to 0.137 kg per capita per day in winter, marking a 19 % increase in the summer. Despite these differences, a paired t-test revealed no statistically significant seasonal variation, with a p-value of 0.435 (> 0.05). Additionally, the impact of socioeconomic conditions on MSW generation was investigated using a one-way ANOVA test, which revealed a statistically significant correlation between household income levels and waste production with p-value = 0.009 (<0.05). This highlights a clear socioeconomic gradient, with waste generation increasing alongside rising income. In addition, the key MSW component was organic waste, suggesting a greater potential for resource recovery of MSW via composting organic waste and recycling other wastes. The possibility of energy generation via incineration was seen as the average energy value of the waste was estimated as 19.7 MJ/kg, computed from proximate and ultimate analysis. This study can act as a baseline for other municipalities in the country in the absence of prior inquiry into seasonal variation of MSW and its energy value in the context of Nepal.