Conventional Approaches for Waste Management—A Canadian Perspective

Abstract

In this chapter, conventional methods for managing hazardous and non-hazardous waste streams are discussed. Non-hazardous solid waste management methods include disposal and diversion. Disposal refers to the removal of the waste by landfilling or thermal treatment such as incineration and solid recovered fuel system. Landfilling, the primary approach of solid waste disposal in Canada, is associated with environmental contamination such as leachate leakage and landfill gas emission. Compared to landfill disposal, thermal treatments can significantly reduce the volume of the waste and recover energy in the form of heat and electricity. However, they generate more air contaminants, bottom ash and fly ash and their operation is costly. Disposal of hazardous waste is performed through a reduction of the volume and toxicity of the waste by physical, chemical, biological and thermal treatments. Examples of these treatments include air stripping, carbon adsorption, hydrolysis, oxidation, reduction, anaerobic digestion, enzyme treatment, incineration, pyrolysis, etc. On the other hand, diversion refers to reducing, reusing or recycling the waste and includes two major approaches of recycling and composting. Recycling materials such as glass, metal, plastic or paper provide an alternative source of materials to the extraction and production of virgin resources. It is performed through the Material Recycling Facility (MRF) that receives, separates and prepares the recyclable materials for later use as raw materials for remanufacturing and reprocessing. Composting is used for organic waste such as food waste, manure, paper, wood, crop residue, etc., converting them into valuable organic fertilizers. In addition to solid waste management, municipal and industrial wastewater, which are the largest amount of generated waste by weight in Canada, are introduced and different treatment levels for each of them are discussed.