Industrial Effluent Testing & Treatment MCQs With Answer

Introduction: This set of MCQs on Industrial Effluent Testing & Treatment is designed for M.Pharm students studying MIP 202T – Scale Up & Technology Transfer. Questions emphasize practical understanding of effluent characteristics, analytical tests (BOD, COD, TOC, TSS), unit operations and processes (equalization, coagulation, biological and advanced oxidation), membrane and disinfection technologies, toxicity and regulatory considerations, and sludge management. The quiz targets critical decision points in designing and evaluating effluent treatment systems for pharmaceutical industries, highlighting parameters that influence process selection, performance monitoring and compliance. Use these questions for self-assessment and rapid revision prior to exams or project work.

Q1. Which parameter is most commonly used as an indicator of biodegradable organic pollution in industrial effluents?

• Biochemical Oxygen Demand (BOD)
• Chemical Oxygen Demand (COD)
• Total Dissolved Solids (TDS)
• pH

Correct Answer: Biochemical Oxygen Demand (BOD)

Q2. Which test estimates the oxygen equivalent of the organic matter oxidizable by a strong chemical oxidant and is widely used for process design?

• Biochemical Oxygen Demand (BOD)
• Chemical Oxygen Demand (COD)
• Total Organic Carbon (TOC)
• Total Suspended Solids (TSS)

Correct Answer: Chemical Oxygen Demand (COD)

Q3. Which measured parameter best correlates with the ionic strength and salinity of an effluent?

• Electrical conductivity
• pH
• Turbidity
• BOD

Correct Answer: Electrical conductivity

Q4. What is the primary function of an equalization tank in an industrial effluent treatment plant?

• Improve sludge dewaterability
• Buffer flow and composition variations (equalization)
• Remove dissolved organics by adsorption
• Final polishing of effluent

Correct Answer: Buffer flow and composition variations (equalization)

Q5. For pharmaceutical effluents with high COD and low biodegradability, which treatment is most effective as a pre-treatment before biological steps?

• Conventional activated sludge
• Advanced oxidation processes (AOP) such as Fenton or ozonation
• Primary sedimentation only
• Screening and grit removal

Correct Answer: Advanced oxidation processes (AOP) such as Fenton or ozonation

Q6. Which unit operation is primarily responsible for removing settleable suspended solids from effluent?

• Secondary biological treatment
• Primary sedimentation
• Filtration through activated carbon
• Membrane ultrafiltration

Correct Answer: Primary sedimentation

Q7. What does the Sludge Volume Index (SVI) indicate in activated sludge systems?

• Electrical conductivity of sludge
• Settleability of activated sludge
• Organic loading rate
• Sludge dewatering rate

Correct Answer: Settleability of activated sludge

Q8. The main aim of coagulation-flocculation in effluent treatment is to:

• Increase dissolved oxygen
• Convert organics to methane
• Remove colloidal and fine suspended particles by destabilization and aggregation
• Reduce salinity

Correct Answer: Remove colloidal and fine suspended particles by destabilization and aggregation

Q9. Which disinfection method is preferred when avoiding formation of halogenated disinfection by-products is a priority?

• Chlorination
• Chlorine dioxide
• Ozonation
• UV irradiation

Correct Answer: UV irradiation

Q10. Which analytical parameter gives a direct quantitative measure of organic carbon content in an effluent?

• Total Suspended Solids (TSS)
• Biochemical Oxygen Demand (BOD)
• Total Organic Carbon (TOC)
• Conductivity

Correct Answer: Total Organic Carbon (TOC)

Q11. Anaerobic digestion of high-strength industrial wastewater primarily produces which valuable gas?

• Carbon monoxide
• Nitrous oxide
• Methane-rich biogas
• Hydrogen chloride

Correct Answer: Methane-rich biogas

Q12. Which membrane process is most appropriate for removing dissolved organic molecules and achieving potable-quality permeate from industrial effluent?

• Microfiltration
• Ultrafiltration
• Nanofiltration
• Reverse osmosis (RO)

Correct Answer: Reverse osmosis (RO)

Q13. Which aquatic organism is commonly used for acute toxicity bioassays of industrial effluents?

• Ames bacterial mutation test
• Daphnia magna immobilization test
• Activated sludge respiration inhibition test
• Algal pigment analysis only

Correct Answer: Daphnia magna immobilization test

Q14. The biodegradability index commonly used to assess whether an effluent is amenable to biological treatment is:

• COD/TSS ratio
• BOD5/COD ratio
• TDS/TSS ratio
• Nitrate/Nitrite ratio

Correct Answer: BOD5/COD ratio

Q15. What is the primary purpose of sludge thickening in an ETP?

• Neutralize pH of sludge
• Reduce sludge volume by removing free water prior to dewatering
• Oxidize organic matter biologically
• Polish effluent for reuse

Correct Answer: Reduce sludge volume by removing free water prior to dewatering

Q16. Which treatment approach relies on hydroxyl radicals to degrade refractory pharmaceutical compounds?

• Biological nutrient removal
• Hydroxyl radical-based AOPs (e.g., Fenton, UV/H2O2)
• Primary clarification
• Sand filtration

Correct Answer: Hydroxyl radical-based AOPs (e.g., Fenton, UV/H2O2)

Q17. In India, which authority is mainly responsible for prescribing effluent discharge standards for industries?

• Food and Drug Administration (FDA)
• Environmental Protection Agency (EPA)
• Central Pollution Control Board (CPCB)
• World Health Organization (WHO)

Correct Answer: Central Pollution Control Board (CPCB)

Q18. For anaerobic reactor design (e.g., UASB) the organic loading and sizing primarily use which parameter?

• Biochemical Oxygen Demand (BOD)
• Chemical Oxygen Demand (COD)
• Total Suspended Solids (TSS)
• pH only

Correct Answer: Chemical Oxygen Demand (COD)

Q19. Which microbial process is most sensitive to low pH and therefore often inhibited if effluent pH is acidic?

• Nitrification
• Denitrification
• Coagulation
• Sedimentation

Correct Answer: Nitrification

Q20. Which tertiary treatment method is commonly used for effective phosphate removal from industrial wastewater?

• Activated carbon adsorption only
• Biological phosphorus removal in all cases
• Chemical precipitation with alum or ferric salts
• Membrane microfiltration alone

Correct Answer: Chemical precipitation with alum or ferric salts

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