**1. Introduction**

Municipal solid waste managemen<sup>t</sup> has emerged as one of the greatest challenges facing many developing countries. Daily human activities lead to the generation of various classes of waste, which is seen as a major environmental threat for many cities in developing nations worldwide [1,2]. The factors affecting such a high rate of change in solid waste generation includes things such as population growth, changing lifestyles, income growth, increasing use of disposable materials, excessive packaging of items, and consumer habits [3,4]. Despite the several investment opportunities that waste managemen<sup>t</sup> offers with a very high return on investment for public and private sectors, most developing countries, including Nigeria, have solid waste managemen<sup>t</sup> issues which are different from those found in industrialized countries in regard to composition, density, political and economic frameworks, quantity of waste, access to waste for collection, awareness, and attitude [4–6]. In developing countries, local authorities spend 77–95% of their revenue on collection and the balance on disposal [7], but are only able to collect around 50–70% of municipal solid waste [8]. In Nigeria, municipal waste densities generally range from 250–370 kg/m<sup>3</sup> [7,9]. Unfortunately, people in many developing countries (including Nigeria) have, until recently, regarded the issue of proper solid waste managemen<sup>t</sup> as trivial, which may have diverted attention away from the most urgen<sup>t</sup> and serious problem of achieving a

fast rate of economic growth. This attitude stems from the belief that solid waste generation is an inevitable price of development [10].

According to [8], there are several factors influencing solid waste collection in Nigeria, some of which are the lack of advanced technology facilities for separation at its source, the strength of solid waste managemen<sup>t</sup> policies and enforcement procedures, environmental education and awareness, and the economic status of individuals, among others. Mahees et al. [11] stated that better solid waste managemen<sup>t</sup> processes should start from the solid waste generation stage. Olukanni et al. [12] and Ogwueleka [7] stated that the volume of solid waste being generated increases at a faster rate than the ability of waste managemen<sup>t</sup> agencies to improve resources required to meet financial and technical resources needed to parallel this growth. According to Bowan and Tieroba [13], solid waste needs to be characterized by sources, generation rates, type of waste produced, and composition in order to monitor and control prevailing waste managemen<sup>t</sup> systems while improving the existing system. A complete understanding of the composition of a waste stream as well as the activities that determine its generation is essential for effective solid waste managemen<sup>t</sup> [14].

However, the concept of recycling is still being explored. This is the extraction and recovery of valuable materials from scraps or other discarded materials employed to supplement the production of new materials. It is essentially adding value to waste, making it economically useful [15–17]. Waste recycling has enormous economic opportunities, including job creation, poverty alleviation, and sustainable development [5]. Recyclable materials in low-, middle-, and high-income countries comprise about 17%, 43%, and 62% of the total waste stream, respectively [16]. Recyclable solid waste include textiles, construction waste, paper, plastic, ferrous and nonferrous metals, and glass. Plastic recycling industries shred plastics into pellets to manufacture other plastics and allied products. Some recycling factories process waste paper and cardboard to make tissue paper, newsprint, or bulk packaging materials. Waste glass is processed by glass or terrazzo companies, nonferrous metals are processed by aluminum smelters, and tin is recovered from aerosol cans [18]. Agunwamba [19] observed that a well-planned recycling program in Nigeria could result in savings of up to 78% in waste managemen<sup>t</sup> costs and 79.5% in landfill avoidance costs. Aside from the economic gains of recycling, environmental benefits, such as the reduction of greenhouse gas emissions, air, and water pollution associated with production from virgin raw materials, are likely to accrue from waste recycling [16].

Literature generally reports that enormous quantities of solid waste are generated daily in the major cities of Nigeria, but exact figures are difficult to determine due to the fact that proper records of collection and disposal are not kept by the authorities responsible [20]. The project at hand used Covenant University as a case study to present an overview of the amount of municipal solid waste which is generated and studied its characterization to ascertain its economic significance. Specific areas chosen were the academic and residential areas for use by staff and students, and the two cafeterias. The aim of this study was to determine the quantity, composition, and generation rate of solid waste in the institution, with specific objectives of gathering statistical data of waste generated, presenting the current state of waste management, characterizing the solid waste generated, and quantifying waste for recycling, recovery, and reuse.

#### *1.1. Study Area*

The study site represents a typical modern community of Nigeria. The Covenant University community, within Canaan Land in Ota town, is in close proximity to the city of Lagos, Nigeria. The community hosts the world's single largest church auditorium with a capacity of 50,000, and runs five (5) worship services every Sunday. Temperatures are high throughout the year, averaging from 25 ◦C to 28 ◦C (77 ◦F to 82 ◦F). The institution has witnessed an increase in population since its inception in 2002, with a current population of above 9000 people and a daily water requirement that is estimated at 136 L/c/day. On average, one person consumes 4 bottles of water per day. Canaan Land has an expanse of 524 acres of land with an array of architectural masterpieces, which consist of the Centre for Learning Resources (university library), college buildings, a 3000-seat student chapel, 22 duplexes with 48 chalets in the Professors' Village, 64 suites at the senior staff gues<sup>t</sup> house, 64 three-bedroom flats in the senior staff quarters, 100 rooms in the university gues<sup>t</sup> house, two cafeterias, 96 two-bedroom apartments, and 24 one-bedroom apartments in the postgraduate halls of residence. In addition to these, there are 10 blocks of student hostels, administrative offices, lecture halls, a gymnasium, and four new engineering workshops. Figure 1 shows the master plan of the institution with selected points of interest presented in Table 1 as marked on the map.

**Figure 1.** Master plan of the institution.



## *1.2. Site-Specific Study*

This study involved sampling, sorting, and weighing the individual components of the waste stream. The site-specific study required a large number of samples to be taken, ensuring that the results were not skewed or misleading. The procedures involved in municipal solid waste characterization for this project using a site-specific study were as follows.

#### *1.3. Selection of a Representative Sample*

It was very important that the samples collected were representative of the waste generation units being studied, and involved things like specifying the target population. The staff population as at 2018 was about 500 persons for academic staff and 600 persons for non-academic staff. Tables 2 and 3 show the staff and students residence populations, respectively.


**Table 2.** Covenant University staff residence population.



#### *1.4. Sample Size*

The sample size depended on the number of solid waste generation units in the sampling area. In the senior staff quarters which consisted of 72 flats (i.e., 9 blocks of 8 flats), 14 flats were sampled. In the professor's village which consisted of 22 duplexes and 48 chalets, 14 units were sampled. In the post-graduate quarters, consisting of 120 flats (i.e., 6 blocks of 20 flats, 96 two-bedroom flats and 24 one-bedroom flats), 24 flats were sampled. In the halls of residence, consisting of 10 blocks (with each block consisting of at least 8 wings), 2 blocks with 2 wings each were sampled. 13 units were sampled among the 64 suites. In the new estate, which consisted of 32 duplexes, 129 three-bedroom flats and 80 two-bedroom flats, 48 units were sampled (i.e., 6 duplexes, 26 three-bedroom flats and 16 two-bedroom flats). Both cafeterias 1 and 2 were sampled.

#### *1.5. Sample Collection*

In Covenant University, solid waste collection is carried out by the use of trucks. The trucks are usually parkers, tippers, and trucks that carry hydraulic rams to compact the waste to reduce its volume and thus be able to carry larger quantities, and this method is also known as the stationary haul collection system. The weight of the total sample was obtained before sorting, and the number of sampling units (households) included in the survey were recorded so that the average weight of waste per household per week could be determined. The solid waste in the institution was also sorted in terms of organic and inorganic materials—"organic" referring to food waste, and "inorganic" referring to PET bottles, tin cans, metal scraps, and the like. The first phase of this project dealt with the collection of waste in different bins—green bins for food waste, red for paper and disposable waste, and blue for PET bottles.

#### *1.6. Sample Analysis*

The samples were sorted into types and classes of solid waste, and the weight of each type and class was recorded. For this survey, the waste was categorized into the following classes—paper, PET bottles, nylons, tetra packs, plastic food packs, tin cans, food waste, and others. Waste was classified because we needed to ge<sup>t</sup> an idea of the amount of recyclable waste from the Covenant University waste stream.

#### **2. Method of Analysis**

The results were analyzed using Equations (1)–(5), respectively. Bar charts were used to express primary data collected to give the weight of characterized household waste per kg/household/day.

$$\text{Per capita waste generated (kg/capital/day)} = \frac{\text{total solid waste per day}}{\text{total population that produces the waste}} \tag{1}$$

$$\text{Average solid waste generated/day (kg/day)} = \frac{\text{total weight generated/week}}{7 \text{ days}}\tag{2}$$

$$\text{Characterization of waste composition (\%)} = \frac{\text{weight of segmented waste}}{\text{weight of total waste}} \times 100\tag{3}$$

$$\text{Average waste generated in a household (kg/day, kg)} = \frac{\text{total waste generated by different households}}{\text{total number of households}} \quad (4)$$

*Average total waste generated by population of a place (kg/day) = per capita waste* × *total population* (5)
