Waste Management Problem
Waste can be defined as materials discarded or generated by living organisms within a natural ecosystem, where the system processes them efficiently and effectively as resources to be reused in a natural cycle. It also refers to residues and refuse resulting from various human activities, such as paper, plastic bags, cardboard, glass, metal containers, food waste, and industrial and construction debris.
With population growth and the massive volume of solid waste generated by humans, the issue of waste has emerged as a significant challenge. Waste management is one of the critical problems faced by nations in the modern environment, directly contributing to environmental degradation. In rural areas, soil, livestock, and poultry waste are primary drivers of environmental pollution unless disposed of in environmentally friendly and sanitary ways.
Recently, the waste problem has worsened due to agricultural and industrial advancements following the Industrial Revolution. This has turned waste disposal into a pressing global and regional issue, requiring significant effort and investment to address. The increasing volume of waste, combined with limited land area, has led to environmental pollution, resource depletion, rising environmental awareness, and disasters caused by improper waste treatment, which negatively impact public health.
Types of Solid Waste
Solid waste varies by its source and nature. Below are the primary categories:
- Urban Solid Waste:
Includes waste generated from industrial activities, residential areas, and companies. It consists of a heterogeneous mix of paper, rubber, leather, cardboard, garden waste, glass, textiles, food scraps, and plastics. - Mining Waste:
This waste comes from drilling, mining, processing, and extracting various minerals. Mining waste significantly impacts the environment and nearby communities. - Agricultural Waste:
Agricultural waste includes residues from crops and livestock farms. This type of waste often contains valuable nutrients and can be reused by collecting and biologically processing it to extract methane gas.
Methods of Waste Disposal
Waste can be disposed of in several ways, depending on the availability of systems and regulations ensuring safe waste treatment. The most common methods include:
1. Landfilling
Waste is placed in ground pits without separating its components or recovering reusable materials. Methane gas is produced as a result of the anaerobic decomposition of organic waste when covered with soil. This method may contaminate groundwater through the infiltration of polluted rainwater, known as leachate, into the aquifer. To prevent contamination, cement or plastic layers are used as barriers in landfills. Environmental and climatic conditions of proposed landfill sites must also be studied.
2. Incineration
Waste is burned in specialized furnaces at temperatures ranging from 900 to 2000°C, with continuous combustion required. The thermal energy generated can be used for district heating or electricity production by heating water pipes in heating networks or producing steam to generate power.
Despite its environmental advantages, this method can pollute the air due to toxic gases released during combustion. It is also unsuitable for certain solid wastes, which are then disposed of through landfilling, along with the ash produced. As a result, sanitary landfilling complements incineration.
3. Recycling
Industrial and urban waste, such as paper, plastic, and food scraps, can be processed and reused as raw materials to manufacture new products. For example, one ton of paper is made from approximately 20 trees, so recycling paper reduces tree consumption for paper production. Organic household waste can also be converted into compost through biological decomposition, where microorganisms like bacteria break down the waste in the presence of air. The resulting compost can enhance soil fertility and support agricultural activities.
4. Traditional Methods
Some countries use traditional methods, such as transporting waste outside cities and accumulating it in designated areas for burning or natural decomposition. This approach is a significant cause of air, water, and soil pollution. Burning waste releases gases containing numerous pollutants like nitrogen oxides and sulfur oxides, contributing to acid rain.
To minimize the risks of this method, waste collection sites must be carefully chosen to reduce environmental harm as much as possible.
