18-Env-A6 Solid Waste Engineering and Management · May 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.
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.
(1) Heating (calorific) value (kJ/kg or Btu/lb) — the net energy that can be recovered per unit mass, which sizes the combustion/boiler capacity and the recoverable steam or electrical output. (2) Moisture content — reduces the net (usable) heating value because energy must first be spent evaporating the water, and high moisture destabilizes combustion. (3) Ash content — the non-combustible residue remaining after combustion, which sets ash-handling and disposal requirements and further reduces effective heating value per unit of as-received waste. (4) Proximate/ultimate analysis — volatile matter and fixed carbon (proximate), plus elemental composition of carbon, hydrogen, oxygen, nitrogen, sulphur and chlorine (ultimate), which govern combustion behaviour and the resulting air emissions (SOₓ, HCl, NOₓ, particulates) that must be controlled.
