Estimating the quantity of solid waste generation in Oyo, Nigeria

Abstract

The study established waste multipliers that could be used in conjunction with the population figure of a city to estimate the quantity of solid waste generation in the developing world. Oyo, a traditional city in Nigeria was the focus of the study. Two sets of data were collected. The first was the information on the socio-economic attributes of residents obtained from 648 households through questionnaires administered using a systematic random sampling technique. The second was the measurement of waste generated in 25% of the households for a week in each of the 12 months of the year. The study established that 23.3% of the residents surveyed have educational qualifications beyond secondary school, with 51.2% engaged in occupations requiring very little or no formal education and 50.9% were in the low-income group. The daily per capita solid waste generation was 0.129 kg. The highest (9.8%) and lowest (6.5%) of the annual quantities of waste were produced in October and February, respectively. Similarly, 20.2% of the weekly generation was produced on Saturday and the 10.2% produced on Thursday was the lowest. Animal dung, which accounted for 18.0%, constituted the highest component of the total solid waste generated. The study further established that the organic component of the waste generation was 75.4%. The results of the regression analysis R2 significant at 0.001 showed that income, household size, social status, occupation, education and season of the year explained 88.8% of waste generation in Oyo. It was established that 50.90 tonnes of solid waste was generated per day in the city in 2005, and the daily generation in the year 2008 is estimated to be 55.20 tonnes. The study concluded that with an average annual population growth of 13 000 people for the town, an additional 1.3 acres of land will need to be legally acquired annually, implying that 10.92—19.68 hectares will be required as dump site(s) over the next 20—30 years.