By Dr. Solmaz Rezaei
Head of research and consulting department
The waste is generally referred to as solid, liquid, and gas material (other than sewage), which is directly derived from human activity and considered redundant. Waste is classified in scientific definition to various types of regular, medical, agricultural, industrial and special, each of which has its own characteristics.
In recent decades, municipal solid waste management has become one of the most important bases of urban management in the world. In general, any solution to waste management should take into account the health, environmental, economic and social aspects. Although there are many ways to dispose solid waste, but in advanced countries, recycling management has become very special in reducing waste and environmental pollution, saving costs, energy and natural resources. . In industrialized and advanced countries, municipal waste management is an over-all activity, and all the measures taken in this area are seen as sustainable development. Despite all the progress made in waste management, it has become particularly important to minimize garbage at source in the formulation of programs due to inevitable complications, such as greenhouse gas emissions. The priority of waste management is to avoid the production, reduction, reuse, recycling and recovery of materials and energy, and finally waste landfill.
In today’s world, the use of innovative municipal waste management strategies based on city intelligence, considering the diversity and volume of waste types, can provide marvelous solutions for urban and urban management in reducing waste and utilizing available capacities. This intelligence provides basic solutions in the areas of waste collection, transportation, processing and disposal. These methods are based on measures that prevent the production of harmful leachate and the emission of greenhouse gases in the environment and produces new and usable products in the recycling process. Some technologies are used in the waste disposal sector and others in the field of energy production, and sometimes the combination of these two methods is used to achieve the desired result. In the evacuation approach, sanitation, composting and biogas production methods can be pointed out, and also the waste incineration, plasma gas generation and fuel generation from waste (RDF) in the energy production approach.
According to the International Energy Agency (IEA), the share of energy generated from urban waste is 1.2% of the total renewable energy, equivalent to 1.5 times the energy from wind and 4 times the solar energy, which reveals the role of sustainable waste management with an energy production approach, more than before.
Nowadays, in waste management processes, new technologies are used that we mention two examples:
Using RFID technology or Radio-Frequency IDentification: In this method, a very small microchip capable of sending radio signals is used. To detect these chips, unlike barcodes, they do not need to be exposed to a barcode reader. Labels containing these microchips in terms of type of waste are installed on the waste bins and readers are attached to the garbage trucks and related data transferred through the GSM system to the central system. This tracking system optimizes the location of waste trucks, garbage collection and transportation routes, and optimizes the process of garbage collection.
Choosing the best landfill site by GIS system: With all the waste recycling methods, waste is eventually buried safely for the environment, which, with all the existing standards, allows the leakage of contaminants and there will be harmful leaks in the underground. The Geographic Information System (GIS) identifies and uses the best landfill site which includes the geological, climatic, groundwater and other characteristics for landfills.
The waste can be used to produce compost or to generate energy by anaerobic digestion. Also, a significant percentage of the waste can be used as alternative fuels or RDFs, which are produced by the separation of energy wastes and drying them to a certain extent, for use in power plants, and in particular cement plants.