18-Env-B5 Industrial & Hazardous Waste Management · May 2014
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 Environmental Protection Act (CEPA), 1999; provincial Environmental Protection / Hazardous Waste Regulations (e.g. BC's Hazardous Waste Regulation, O.Reg. 347 in Ontario).
All eighteen 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.
An equalization basin dampens the swings in an industrial wastewater's flow and strength before it reaches downstream treatment, for three main purposes: (1) dampening hydraulic (flow-rate) surges, so downstream units are sized on a steadier, closer-to-average flow rather than the peak instantaneous discharge, avoiding hydraulic overload and washout of biological solids; (2) dampening concentration/loading surges (BOD, TSS, pH, or an intermittent toxic slug), which protects biological treatment from shock loading and gives operators time to detect and respond to an upset batch dump before it reaches the biology; and (3) providing a controlled point for pH neutralization, nutrient addition or other chemical conditioning, since blending and buffering are far more reliable on a homogenized equalized stream than on a raw, highly variable one.
