18-Env-B9 Environmental Chemistry and Microbiology · May 2016
Nivaar worked solution (AI-drafted; not reviewed by a licensed engineer)
National Exams — May 2016 — 04-Env-B9, Environmental Chemistry/Microbiology. 3 hours duration; closed-book exam (one 8.5×11" aid sheet, both sides, permitted; any non-communicating calculator permitted). The paper has two sections — Section 1: Chemistry (8 questions, 50 marks) and Section 2: Microbiology (12 questions, 50 marks) — twenty questions constitute the complete exam and all are answered below. Total examination mark 100.
Reference texts. Davis & Cornwell, Introduction to Environmental Engineering (6th ed.) (water chemistry, disinfection, water/wastewater microbiology, indicator organisms); Metcalf & Eddy (Tchobanoglous, Stensel, Tsuchihashi & Burton), Wastewater Engineering: Treatment and Resource Recovery (5th ed.) (chemical unit processes, chemical phosphorus precipitation, biomass stoichiometry, activated-sludge microbiology, BOD/SRT/F–M); Guidelines for Canadian Drinking Water Quality (Health Canada); MWH's Water Treatment: Principles and Design (3rd ed.) (advanced treatment, UV disinfection, potable reuse).
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.
Tuberculosis (bacterium Mycobacterium tuberculosis) — spread via airborne droplet nuclei expelled by coughing, which can remain suspended and infectious for extended periods in poorly ventilated spaces.
Legionellosis (Legionnaires’ disease) (bacterium Legionella pneumophila) — contracted by inhaling fine aerosolized water droplets from contaminated sources such as cooling towers, whirlpool spas or building water systems, making it directly relevant to environmental/building-services engineering design.
Influenza (influenza virus) — transmitted principally through respiratory droplets and aerosols expelled by coughing, sneezing or talking, and readily spread in enclosed, crowded, poorly-ventilated indoor environments.
