18-Env-B5 Industrial & Hazardous Waste Management · May 2013
Nivaar worked solution (AI-drafted; not reviewed by a licensed engineer)
Reference texts: Nemerow & Dasgupta, Industrial and Hazardous Waste Treatment, 2nd ed.; Metcalf & Eddy, Wastewater Engineering: Treatment and Resource Recovery, 5th ed.; Davis & Cornwell, Introduction to Environmental Engineering, 6th ed.; LaGrega, Buckingham & Evans, Hazardous Waste Management, 2nd ed.; CCME, Guidelines for the Management of Biomedical Waste in Canada (1992); Canadian Nuclear Safety Commission (CNSC) regulatory framework and NWMO Adaptive Phased Management; Canadian Environmental Protection Act (CEPA), 1999.
All nineteen questions are compulsory on this paper and are answered in full below.
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.
Pharmaceuticals and personal-care products (PPCPs) largely enter the aquatic environment through wastewater because conventional secondary treatment was never designed to remove them, so effective strategies operate at both the source and the treatment plant. Source reduction through medication take-back and disposal programs — pharmacy and municipal take-back depots that keep unused medication out of the toilet and sink — addresses the single largest avoidable input, since flushing unused medication is otherwise a direct, concentrated discharge route. Advanced/tertiary treatment at the wastewater plant — granular activated carbon adsorption, ozonation or other advanced oxidation processes, and membrane filtration (nanofiltration/reverse osmosis) — can remove a substantial fraction of the PPCPs that conventional biological treatment passes through, and is increasingly specified at plants discharging to sensitive receiving waters. Extended producer responsibility and green pharmacy design — regulatory and industry programs that fund take-back infrastructure, plus formulating drugs to biodegrade more readily or to be prescribed/packaged in quantities that reduce leftover medication — reduce the mass of PPCPs entering the waste stream in the first place, complementing end-of-pipe treatment rather than replacing it.
