An Overview of Various Waste Management Techniques
Keeping up with the waste generated and implementing proper reuse or recycling techniques requires planning, resources, scientific knowledge, and logistical capabilities.
Quite often municipal corporations have to make a choice between the various modes of managing wastes. Some of the popular techniques include landfilling, composting or incinerating. The right method needs to be selected according to the categories of wastes produced. Waste to energy conversion is an ideal solution as it creates energy and heat from waste products. It, however, does have certain environmental impacts.
Waste management companies and governments are also under pressure to ensure that the various waste management techniques are environmentally friendly. While landfilling and composting have its advantages, combustion of wastes and the treatment of waste to create energy fuels are gaining popularity.
Basic techniques of waste to energy generation
The process of generating energy from waste sounds like something out of sci-fi, but it is possible to convert biodegradable and non-biodegradable wastes into energy sources. There is a wide range of technologies that use four basic methods of converting waste to energy sources. The four basic processes are mentioned below.
- Thermal Conversion- Waste incinerators typically work on the principle of the thermal conversion. Here the waste products are degraded at very high temperatures which results in the complete oxidation of the waste. The final products of thermal conversion are usually steam, ash, and purified flue gas.
- Biochemical conversion- Biomethane is produced by this chemical process through processes such anaerobic digestion and fermentation of wastes. The enzymatic decomposition of the organic wastes through the action of microbes produce methane, alcohol and a variety of other energy sources.
- Thermochemical conversion- Used in processes like pyrolysis and gasification, the high organic waste matter is forced to decompose under high temperatures to generate fuel gas, oil or direct heat. Perfects waste for this process is non-biodegradable organic waste with extremely low moisture content. The final products of this process are typically used to generate heat or can be further treated to provide a variety of other products.
- Electrochemical conversion- Conversion of organic wastes into various kinds of MFCs or Microbial fuel cells is done through the decomposition of wastes under an electric discharge. This method is based on the oxidation and reduction mechanisms of immobilized microbial cells for generating electricity and bio-hydrogen.
There are a lot of factors involved in deciding the right technology for the various methods mentioned above. The nature and quantity of waste, the energy projections and the public mentality towards the various processes due to their environmental impacts are all important factors that should be considered. Most of these processes require the segregation and treatment prior to decomposition. Added to this there are a lot of other methods such as plasma gasification and the creation of fuel pellets that are often used in waste-to-energy plants.