18-Env-A6 Solid Waste Engineering and Management · December 2014
Nivaar worked solution (AI-drafted; not reviewed by a licensed engineer)
Reference texts: Tchobanoglous, Theisen & Vigil, Integrated Solid Waste Management: Engineering Principles and Management Issues; Vesilind, Worrell & Reinhart, Solid Waste Engineering; Davis & Cornwell, Introduction to Environmental Engineering (6th ed.); CCME, Guidance Document on Landfill Gas Management; Canadian Environmental Protection Act, 1999.
This paper prints marks IN FRONT of the question number on every line (e.g. "5 1. What are the elements…", "4 16. All 29 questions are answered in full.
Question text not reproduced: the examination questions are © Engineers and Geoscientists BC. Open the official past paper (linked at the top of this page) to read the question, then follow the worked solution below.
Gaseous emissions: carbon dioxide (CO₂, a greenhouse gas), nitrogen oxides (NOₓ, from combustion-air nitrogen and fuel-bound nitrogen), sulphur dioxide (SO₂, from sulphur in the waste), hydrogen chloride (HCl, from chlorinated plastics such as PVC), dioxins and furans (products of incomplete combustion/de novo synthesis, tightly regulated), and volatilized mercury and other trace metals. Particulate emissions: fly ash carried in the flue gas, which itself carries adsorbed heavy metals and can require dedicated particulate control (baghouse/electrostatic precipitator) to meet emission limits. Beyond the stack emissions, a thermal recovery system also produces bottom ash and fly ash residue requiring disposal (potentially as hazardous waste depending on metal content), wastewater/blowdown from wet scrubbing systems if used, and secondary impacts such as noise from induced-draft fans and truck traffic.
