Solid Waste Management: A Theoretical View
2.2 Types of solid waste
2.2.1 Strategies for the improvement in solid waste management
• Strategic service planning- in implementing the solid waste management system in a metropolitan area demographic and industrial growth should be considered. Services are provided based on the people's demand and affordability, mostly focusing on urban poor people. At a national and provincial level the policy framework should link public health, environment and decentralization. Incentives is the best measurer that can be used by local authorities to deliver sufficient services, gain more costs from users, and work hand in hand with other municipalities.
• More efficient operational management-both private and public sectors should be involved in decision-making mostly facility siting and design service delivery. Allowing people to participate in taking decisions will exacerbate the success of any proposed project. On the other hand
participation will limit the NIMBY (Not In My Back Yard) syndrome, which usually hinder development in urban areas. On the other side private sectors
pmiicipation lower costs and improve efficiency and are used to mobilize investment funds and give new ideas and skills needed.
• More efficient financial management-in most countries generators of waste and the government share the cost of waste collection, transfer and disposal.
Charges imposed to those who generate waste can be used as incentives
whereby people who generate more are to pay more, and this help to recover the portion of costs for solid waste management. In some instance people are willing to pay for collection but not for disposal in landfills. The management capacity of municipal authorities and corresponding municipal finance system should be improved as a way to improve solid waste management.
• Improved environmental management-the sanitary landfill is the only choice left to be used for waste disposal, so there is a need to close dump sites and finance the operation of landfills. The lack of experience and financial resources hinders management of the landfill, so there is a need for financial and technical assistance to the lower- and middle-income countries.
Municipalities also have a responsibility to help each other because environmental problem in one area can affect the other. (Fuggle and Rubie, 1994)
2.3 Waste Management Processes
There are six waste management process involved in the waste stream and each process will be discussed in details in the whole section of 2.3.
Figure 2.1
Waste generation Storage
+
• . - - - COlltction---,.
Transfer! transportation ...
I---l+---.~
ProcessinglremovalI
L - -_ _ _ _ _ _ _ _ _ ~~ Disposal ...I
Source: Fuggle and Rabie, 1994
2.3.1 Waste generation, handling, and separation
Storage of waste in a container is not the only activity in handling waste but other activities include the transportation of a container to the collection point and return the container to its point. Different people responsible for the handling of waste generated on different onsite sources. Different handling and separation methods are used at residential and the commercial sources. Separation methods are used at residential and the commercial sources for purposes of recycling waste materials (Bradshaw et ai, 1992).
The generation of waste in any urban area depends on the time of the day, day of the week, week of the month and month of the year. For example during month ends people generate more since they have more money to buy compared to the beginning of the month. Also during Christmas or vacation times people receive bonus and they generate more waste. Weather conditions, especially moisture content can impact
size of waste generated or waste to be disposed off. In the development of the solid waste management solution moisture, particle size, chemical makeup, density, and composition should be taken into consideration. (Bradshaw, 1992)
There are four levels involved in the handling of municipal solid waste, those are source reduction (where manufacturers has to produce what contains fewer toxins and less packaging, and people have to buy what is durable and non-disposable products); recycling and reuse (where recycling helps to prevent useful material from being placed in landfills, reuse save energy and natural resources); waste combustion (to provide benefit of energy production); and landfill (used to keep waste that cannot be recycled or combusted, and this included even the residues from waste combustion). The waste handling in the residential dwelling differs from the commercial facilities and the brief overview of this will be done below. (Bradshaw et aI, 1992).
2.3.1.1 Residential dwelling
At this source houses with more than one floor are used to classify the methods used in handling and separation of waste. There are three different ways that can be used to classify methods at this source. Firstly, at low-rise detached dwelling that has floors less than four. In this dwelling it's the responsibility of the residents or tenant to place solid wastes, generated from different locations on the containers. And in most communities of US that fall under category are not expected to separation waste but instead to store mixed waste with little or no standardization.
At some stages people had to separate recyclable materials and store it on the separate bag or container, and then transport the container to the collection point.
Secondly medium-rise apatiment are those with floors between four and seven. In
these apartments, the residents had to place containers outside their doors and waste collectors pick up waste from each door. (Bradshaw et ai, 1992).
According to Tchobanoglous (1993), storage location and collection methods vary with basement storage, outdoors storage, and compactor storage. In basement storage the owner of the building provides on area where people carry their recyclable and non-recyclable waste and deposit it on the right place. Then the maintenance staff transports containers to the curbside collection area, and retum containers after collection. In the outdoor storage the container is outside and tenants had to carry their waste and recyclable material to the appropriate container, then the collection vehicle is responsible to empty the container (Tchobanoglous, et aI, 1993).
2.3.1.2 Commercial facilities
Commercial dwelling wastes are collected from individual offices or work location and put on containers. But for most commercial building this is the problem since wastes are emptied from containers to burlap drop cloths. If these cloths are full before collection time there could be bad odors. Any onsite storage of solid wastes takes consideration of the "effect of storage on the component, type of container to be used, container location, and public health and aesthetics," (Tchobanoglous, 1993).
The effect of storing wastes involves things like biological decomposition that result due to bacteria and fungi if food and other waste are placed in onside storage containers. If wastes are mixed together paper can absorb moisture from food depending on duration between the collections. The contamination of major waste components takes place if wastes are stored for long time. Therefore this reduces recycling possibility (Tchobanoglous, et aI, 1993). Types of container to be used depend on characteristics of solid waste to be collected, collection frequency and the
space for placement. Low-rise dwelling in a commercial dwelling use light containers that are easy to handle since collection is manually. Highly loaded containers can cause injuries to collectors. These containers can be in a metal or plastic fonn depending on the homeowner. The metal container is noisy and can be damaged when emptied while ultraviolet rays can bum plastic containers (Bradshaw, et aI, 1992).
Although individual containers are used for one apartment, in areas where apartments are close to each other people share containers. So if the container is full collectors have to pick it up otherwise people will litter anywhere. Medium-size and high-size apartments use chutes; separate storage containers are not used and wastes are stored in containers on the premises between collections. These containers include the large open-top containers, enclosed storage containers and special containers used in conjunction with processing equipment. Containers are located on the sides or near the house, in alleys where alley collection is used and in garage where available. (Bradshaw et ai, 1992).