16-Civ-B5 Water Supply and Wastewater Treatment
Worked solutions to 13 past sittings (2013–2019), 67 questions. Pick a sitting, or start from a topic below.
- December 2019
- December 2018
- May 2018
- December 2017
- May 2017
- December 2016
- May 2016
- December 2015
- May 2015
- December 2014
- May 2014
- May 2013
- Undated paper
Topics across the sittings
Topics that come up in more than one sitting, taken from the headings of our worked solutions. A topic counts once per sitting.
- Discharge (3 sittings): December 2019 Q5 · May 2018 Q5 · December 2017 Q5
- Filtration (3 sittings): December 2018 Q4 · December 2016 Q4 · May 2015 Q4
- Wastewater Characteristics (3 sittings): December 2018 Q1 · December 2016 Q1 · May 2016 Q1
- Wastewater Practice (3 sittings): December 2017 Q1 · May 2017 Q1 · December 2014 Q1
- Chlorination Chemistry (2 sittings): December 2016 Q2 · May 2014 Q2
- Clarifier sizing (2 sittings): December 2018 Q5 · December 2016 Q5
- Coagulation Mechanisms (2 sittings): December 2019 Q4 · December 2017 Q4
- Define (2 sittings): December 2019 Q1 · December 2017 Q1
- Differentiate (2 sittings): December 2019 Q1 · December 2017 Q1
- Disinfection Efficiency (2 sittings): December 2019 Q2 · December 2017 Q2
- Distinctions in Water (2 sittings): May 2017 Q1 · December 2014 Q1
- Filtration mechanisms (2 sittings): May 2014 Q2 · Undated paper Q4
- Hardness (2 sittings): December 2016 Q2 · December 2015 Q1
- Indicator Organisms (2 sittings): December 2019 Q2 · December 2017 Q2
- Oxygen Demand (2 sittings): May 2017 Q4 · December 2014 Q4
Questions by sitting
December 2019
- Question 1: Define and Differentiate
- Question 2: pH and Disinfection Efficiency; Indicator Organisms
- Question 3: Ammonia in Effluents; Activated Sludge with Anaerobic Digestion
- Question 4: Coagulation Mechanisms; Water Distribution Systems
- Question 5: Discharge and Velocity in a Partly Full Sewer
December 2018
- Question 1: Significance of five water and wastewater characteristics
- Question 2: Alkalinity speciation from a two-end-point titration; UV disinfection
- Question 3: Solids retention time and solids loading rate; choice of sludge digestion process
- Question 4: Filtration, coagulation and contaminant-removal mechanisms in water treatment
- Question 5: Facultative lagoon; activated-sludge SRT and clarifier sizing
May 2018
- Question 1: Definitions and significance of five treatment parameters
- Question 2: Chlorine chemistry and pH; water distribution system layouts
- Question 3: Suspended-solids test and the high-rate anaerobic digester
- Question 4: Process schematic for a turbid, hard, iron-bearing surface water
- Question 5: Discharge and velocity in a part-full sewer
December 2017
- Question 1: Define and Differentiate — Five Pairs from Water and Wastewater Practice
- Question 2: pH and Disinfection Efficiency; Indicator Organisms
- Question 3: Ammonia in Treated Effluents; Stages of Anaerobic Sludge Digestion
- Question 4: Coagulation Mechanisms; Requirements of a Water Distribution System
- Question 5: Partial Flow in a 600 mm Sewer — Discharge and Velocity
May 2017
- Question 1: Definitions and Distinctions in Water and Wastewater Practice
- Question 2: Ion Exchange Softening and the Significance of Five Water Quality Parameters
- Question 3: Receiving-Water Assimilative Capacity and the Revised Phosphorus Limit
- Question 4: Conventional Activated Sludge — Tank Sizing, Clarifier Loading and Oxygen Demand
- Question 5: The Rapid Sand Filter — Principle, Ripening, Backwash and Air Scour
December 2016
- Question 1: Water and Wastewater Characteristics
- Question 2: Chlorination Chemistry; Taste, Odour and Hardness
- Question 3: Solids Retention Time, Surface Overflow Rate, and Anaerobic Sludge Stabilization
- Question 4: Filtration and UV Disinfection in Water Treatment
- Question 5: Trickling Filter Operation; Activated Sludge SRT and Clarifier Sizing
May 2016
- Question 1: Significance of Five Water and Wastewater Characteristics
- Question 2: Chlorine Demand, the Breakpoint Curve and the pH Dependence of Chlorination
- Question 3: Effluent Limits on cBOD, Ammonia and Phosphorus, and the Sludge Train
- Question 4: UV Disinfection, Rapid Sand Filtration and the Settling Regimes
- Question 5: The Activated Sludge Process, and the SRT, SOR and SLR of a Given Plant
December 2015
- Question 1: Treatment Train for a Lake Supply with TSS, Hardness and Taste-and-Odour Problems
- Question 2: Total, Volatile and Inorganic Suspended Solids of a Sludge Sample
- Question 3: Significance and Control of Ammonia in Treated Effluents
- Question 4: Inter-Particle Bridging, Sweep Coagulation and Ionic Layer Compression
- Question 5: Biodegradable and Total COD from a Measured cBOD 5
- Question 6: TSS Removal in a Sedimentation Tank Depends on Surface Area, Not Depth
- Question 7: The Four Biochemical Stages of Anaerobic Sludge Digestion
May 2015
- Question 1: Impact of Wastewater Characteristics on Receiving Waters
- Question 2: Oxygen-Demand Definitions and Water-Quality Parameters
- Question 3: Coagulation–Flocculation and Taste and Odour Control
- Question 4: Filtration, Sedimentation and Hardness Removal
- Question 5: Principles and Operation of a Trickling Filter
December 2014
- Question 1: Definitions and Distinctions in Water and Wastewater Practice
- Question 2: Ion-Exchange Softening and the Significance of Selected Water-Quality Parameters
- Question 3: Receiving-Water Assimilative Capacity and the Revised Effluent Phosphorus Limit
- Question 4: Activated-Sludge Aeration Tank, Secondary Clarifier Loadings and Oxygen Demand
- Question 5: Working Principle and Operation of a Rapid Sand Filter
May 2014
- Question 1: Definitions and Significance of Five Treatment Parameters
- Question 2: Filtration Mechanisms and Chlorination Chemistry
- Question 3: New Effluent Limits at the Expanded Plant Capacity
- Question 4: Secondary Clarifier Sizing, Solids Loading and Sludge Age
- Question 5: Process Schematic for a Hard, Turbid, Iron-Bearing Raw Water
May 2013
- Question 1: Water and wastewater quality parameters
- Question 2: Settling regimes and the mechanisms of coagulation
- Question 3: Effluent phosphorus limit from receiving-water assimilative capacity
- Question 4: Primary clarifier volume, overflow rate, and the choice between a second tank and a deeper tank
- Question 5: Trickling filter — principle, working, and operating problems
Undated paper
- Question 1: Definitions and their significance
- Question 2: pH and disinfection; municipal flow projection
- Question 3: Distribution systems; load-based effluent limits
- Question 4: Filtration mechanisms; chlorine residuals; break-point
- Question 5: Partial flow in a 300 mm sewer