Water pollution MCQs With Answer

Water pollution MCQs With Answer tailored for B. Pharm students provide focused practice on water quality, contaminants, toxicology, and treatment processes relevant to pharmaceutical sciences. This concise, SEO-friendly introduction highlights key topics such as organic and inorganic contaminants, microbial hazards, pharmaceutical residues, water quality parameters (BOD, COD, DO, pH, turbidity), analytical methods, and remediation technologies. Understanding these concepts helps B. Pharm students assess environmental impacts, design safer formulations, and engage in regulatory compliance and wastewater management. Practical MCQs improve exam readiness and clinical relevance by linking theory to real-world water safety challenges. Now let’s test your knowledge with 50 MCQs on this topic.

Q1. Which parameter primarily indicates the amount of biodegradable organic matter in water?

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

Correct Answer: Biochemical Oxygen Demand (BOD)

Q2. What is the most common microbial indicator used to assess fecal contamination in drinking water?

• Pseudomonas aeruginosa
• Escherichia coli
• Staphylococcus aureus
• Bacillus subtilis

Correct Answer: Escherichia coli

Q3. Which of the following is classified as an emerging contaminant of concern in aquatic environments related to pharmacy?

• Chloride ions
• Pharmaceutical residues (antibiotics, hormones)
• Sodium bicarbonate
• Calcium carbonate

Correct Answer: Pharmaceutical residues (antibiotics, hormones)

Q4. Which treatment process is most effective for removing suspended solids and reducing turbidity?

• Activated carbon adsorption
• Coagulation and flocculation
• Reverse osmosis
• Chlorination

Correct Answer: Coagulation and flocculation

Q5. Chemical Oxygen Demand (COD) differs from BOD because COD measures:

• Only biodegradable organic matter
• Total oxidizable organic matter including non-biodegradable fractions
• Only inorganic pollutants
• Total suspended solids

Correct Answer: Total oxidizable organic matter including non-biodegradable fractions

Q6. Which method is commonly used to quantify specific pharmaceutical compounds in water?

• Gravimetric analysis
• High-performance liquid chromatography (HPLC)
• Titration with NaOH
• Colorimetric chlorine test

Correct Answer: High-performance liquid chromatography (HPLC)

Q7. Eutrophication in aquatic systems is primarily caused by excess:

• Heavy metals
• Nutrients such as nitrogen and phosphorus
• Salinity
• Dissolved oxygen

Correct Answer: Nutrients such as nitrogen and phosphorus

Q8. Which disinfectant can form harmful disinfection by-products (DBPs) when reacting with organic matter?

• Ozone
• Sodium bisulfite
• Chlorine
• Activated carbon

Correct Answer: Chlorine

Q9. Which heavy metal is well known for causing neurotoxicity and is monitored in water quality assessments?

• Iron
• Lead
• Calcium
• Magnesium

Correct Answer: Lead

Q10. Total Dissolved Solids (TDS) in water primarily measure:

• Suspended particles visible to the eye
• Dissolved inorganic salts and small organic molecules
• Only bacterial contamination
• Color intensity

Correct Answer: Dissolved inorganic salts and small organic molecules

Q11. Which process is most suitable for removing dissolved ionic contaminants like heavy metals from wastewater?

• Sedimentation
• Membrane processes such as reverse osmosis or nanofiltration
• Filtration through sand only
• UV disinfection

Correct Answer: Membrane processes such as reverse osmosis or nanofiltration

Q12. Which analytical parameter indicates the oxygen available for aquatic life?

• Biochemical Oxygen Demand (BOD)
• Dissolved Oxygen (DO)
• pH
• Conductivity

Correct Answer: Dissolved Oxygen (DO)

Q13. Which term describes pollution entering water bodies from diffuse sources like agricultural runoff?

• Point source pollution
• Non-point source pollution
• Thermal pollution
• Atmospheric deposition only

Correct Answer: Non-point source pollution

Q14. Why are antibiotics in wastewater a public health concern?

• They increase water hardness
• They promote development of antibiotic-resistant bacteria
• They decrease pH drastically
• They increase turbidity

Correct Answer: They promote development of antibiotic-resistant bacteria

Q15. Which process removes natural organic matter and improves taste and odor but also reduces DBP precursors?

• Chlorination
• Activated carbon adsorption
• Ultraviolet irradiation
• Flocculation only

Correct Answer: Activated carbon adsorption

Q16. The presence of coliforms in treated drinking water indicates:

• Excessive hardness
• Potential fecal contamination or treatment failure
• High levels of organic solvents
• High nitrate concentration

Correct Answer: Potential fecal contamination or treatment failure

Q17. Which parameter is most affected by algal blooms caused by nutrient pollution?

• Total suspended solids only
• Dissolved oxygen, especially causing hypoxia
• Chloride concentration
• Conductivity reduction

Correct Answer: Dissolved oxygen, especially causing hypoxia

Q18. Photodegradation in surface waters primarily affects which class of contaminants?

• Inert salts
• Organic contaminants sensitive to sunlight, such as some pharmaceuticals and pesticides
• Heavy metals
• Colloidal clay particles

Correct Answer: Organic contaminants sensitive to sunlight, such as some pharmaceuticals and pesticides

Q19. Which unit operation in wastewater treatment relies on microbial degradation of organics under aerobic conditions?

• Primary sedimentation
• Activated sludge process
• Coagulation
• Chlorination

Correct Answer: Activated sludge process

Q20. Which technique is preferred for rapid on-site detection of residual chlorine in treated water?

• Mass spectrometry
• Colorimetric test kits
• HPLC
• Atomic absorption spectroscopy

Correct Answer: Colorimetric test kits

Q21. Which of the following is a primary method to remove phosphorus from wastewater?

• Biological uptake in enhanced biological phosphorus removal (EBPR)
• Simple sedimentation
• UV disinfection
• pH adjustment alone

Correct Answer: Biological uptake in enhanced biological phosphorus removal (EBPR)

Q22. Which parameter is measured to estimate the organic carbon content in water?

• Total Organic Carbon (TOC)
• Electrical conductivity
• Hardness as CaCO3
• Alkalinity

Correct Answer: Total Organic Carbon (TOC)

Q23. What is the main advantage of membrane bioreactors (MBRs) compared to conventional activated sludge?

• Lower energy usage always
• Higher biomass retention and better effluent quality
• No sludge production
• They eliminate the need for pre-treatment

Correct Answer: Higher biomass retention and better effluent quality

Q24. Which contaminant group commonly contributes to thyroid disruption and is monitored in water?

• Organophosphate pesticides only
• Perchlorate and certain endocrine-disrupting chemicals
• Inert salts like sodium chloride
• Alkaline earth metals

Correct Answer: Perchlorate and certain endocrine-disrupting chemicals

Q25. In assessing chronic toxicity of a pollutant to aquatic organisms, which type of test is usually performed?

• Short-term LC50 acute test
• Long-term chronic exposure test assessing reproduction and growth
• pH titration
• Conductivity mapping

Correct Answer: Long-term chronic exposure test assessing reproduction and growth

Q26. Which process is effective at removing viruses from water?

• Coagulation alone
• Membrane filtration (e.g., ultrafiltration) and disinfection (chlorination/UV)
• Simple sand filtration only
• Flocculation without disinfection

Correct Answer: Membrane filtration (e.g., ultrafiltration) and disinfection (chlorination/UV)

Q27. Which water quality parameter strongly influences the toxicity and speciation of heavy metals?

• Turbidity only
• pH
• Color
• Odor

Correct Answer: pH

Q28. Adsorption onto activated carbon is most effective for removing which type of contaminants?

• Highly ionic inorganic salts
• Hydrophobic organic compounds and many pharmaceuticals
• Colloidal clay particles
• Dissolved oxygen

Correct Answer: Hydrophobic organic compounds and many pharmaceuticals

Q29. Which regulatory approach sets permissible limits for contaminants in drinking water?

• Environmental Impact Assessments only
• Water quality standards and guidelines (e.g., WHO, national standards)
• Laboratory SOPs only
• Manufacturer safety data sheets

Correct Answer: Water quality standards and guidelines (e.g., WHO, national standards)

Q30. Which analytical technique is most appropriate for trace-level detection of pharmaceuticals in surface water?

• UV-Visible spectrophotometry without separation
• Liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS)
• Simple conductivity measurement
• Gravimetric assay

Correct Answer: Liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS)

Q31. Which action helps reduce pharmaceutical pollution at the source?

• Improper disposal of medicines down the sink
• Take-back programs and proper disposal of unused medications
• Overuse of antibiotics in humans and animals
• Flushing expired drugs into sewer

Correct Answer: Take-back programs and proper disposal of unused medications

Q32. What is the principal cause of thermal pollution in aquatic systems?

• Discharge of heated industrial effluents
• Excessive nutrient input
• Heavy metal contamination
• Oil spills

Correct Answer: Discharge of heated industrial effluents

Q33. Which advanced oxidation process generates hydroxyl radicals for degrading persistent organics?

• Coagulation with alum
• Ozonation combined with hydrogen peroxide (O3/H2O2) or UV/H2O2
• Simple chlorination
• Sand filtration

Correct Answer: Ozonation combined with hydrogen peroxide (O3/H2O2) or UV/H2O2

Q34. What does turbidity measure in water?

• Concentration of dissolved inorganic salts
• Cloudiness due to suspended particles scattering light
• Amount of dissolved oxygen
• Concentration of organic carbon

Correct Answer: Cloudiness due to suspended particles scattering light

Q35. In groundwater contamination, which pollutant commonly associated with agriculture is a major health concern?

• Phosphate detergents only
• Nitrate from fertilizers
• Silica
• Atmospheric oxygen

Correct Answer: Nitrate from fertilizers

Q36. Which term describes a compound that disrupts endocrine function at low concentrations?

• Bioaccumulative metal
• Endocrine-disrupting chemical (EDC)
• Inert tracer
• Colloid

Correct Answer: Endocrine-disrupting chemical (EDC)

Q37. Which of the following best describes biodegradation of pollutants in water?

• Chemical breakdown only by sunlight
• Microbial metabolic processes converting complex compounds to simpler products
• Physical removal by filtration only
• Precipitation of salts

Correct Answer: Microbial metabolic processes converting complex compounds to simpler products

Q38. What is the main concern with persistent organic pollutants (POPs) in aquatic systems?

• They evaporate quickly
• They bioaccumulate and persist, posing long-term ecological and human health risks
• They are easily degraded by bacteria
• They only affect water color

Correct Answer: They bioaccumulate and persist, posing long-term ecological and human health risks

Q39. Which parameter is used to measure the ionic conductivity of water and infer salinity?

• pH
• Electrical conductivity (EC)
• Biochemical oxygen demand
• Coliform count

Correct Answer: Electrical conductivity (EC)

Q40. Which remediation technique uses plants to remove, stabilize, or degrade contaminants in water or wetlands?

• Thermal desorption
• Phytoremediation
• Electroplating
• Ozonation only

Correct Answer: Phytoremediation

Q41. Which practice in pharmaceutical manufacturing reduces risk of contaminant release to water bodies?

• Discharging untreated effluent
• Implementing wastewater pre-treatment and zero liquid discharge where feasible
• Flushing process wastes into storm drains
• Mixing wastes with potable water

Correct Answer: Implementing wastewater pre-treatment and zero liquid discharge where feasible

Q42. Which indicator is most useful for detecting recent contamination by warm-blooded animals?

• Total suspended solids
• Fecal coliforms or E. coli presence
• Heavy metal concentration
• Chloride levels

Correct Answer: Fecal coliforms or E. coli presence

Q43. Which by-product is commonly produced when chlorine reacts with natural organic matter?

• Ozone
• Trihalomethanes (THMs)
• Activated carbon
• Nitrite

Correct Answer: Trihalomethanes (THMs)

Q44. What is bioaccumulation in the context of aquatic pollution?

• Rapid dilution of pollutants
• Progressive build-up of chemicals in an organism over time
• Immediate breakdown of contaminants
• Physical settling of particles

Correct Answer: Progressive build-up of chemicals in an organism over time

Q45. Which sampling practice is important to obtain representative water quality data?

• Collecting a single grab sample regardless of variability
• Using composite sampling over time or locations to capture variation
• Sampling only during storms
• Only sampling surface scum

Correct Answer: Using composite sampling over time or locations to capture variation

Q46. Which factor accelerates corrosion and mobilization of metals in drinking water distribution systems?

• Neutral pH and low chlorine residual
• Low alkalinity and acidic pH
• High dissolved oxygen only
• High turbidity exclusively

Correct Answer: Low alkalinity and acidic pH

Q47. Which class of pesticides is known for persistence and potential to bioaccumulate?

• Organophosphates (short-lived)
• Organochlorines (e.g., DDT)
• Biodegradable ionic surfactants
• Simple alcohols

Correct Answer: Organochlorines (e.g., DDT)

Q48. Which approach combines physical separation and biological degradation to treat municipal wastewater?

• Membrane distillation alone
• Primary sedimentation followed by secondary biological treatment (e.g., activated sludge)
• Only chemical oxidation
• Direct discharge without treatment

Correct Answer: Primary sedimentation followed by secondary biological treatment (e.g., activated sludge)

Q49. What role does dissolved organic carbon (DOC) play in drinking water treatment?

• It has no effect on treatment
• It acts as a precursor for disinfection by-products and affects treatment efficacy
• It reduces turbidity directly
• It always improves taste

Correct Answer: It acts as a precursor for disinfection by-products and affects treatment efficacy

Q50. Which monitoring metric would a B. Pharm student focus on when assessing risk of drug residues in a river used for irrigation?

• Presence and concentration of specific pharmaceuticals and ecotoxicity assays
• Only pH measurement
• Total suspended solids without chemical analysis
• Color alone

Correct Answer: Presence and concentration of specific pharmaceuticals and ecotoxicity assays

G S Sachin

I am a Registered Pharmacist under the Pharmacy Act, 1948, and the founder of PharmacyFreak.com. I hold a Bachelor of Pharmacy degree from Rungta College of Pharmaceutical Science and Research. With a strong academic foundation and practical knowledge, I am committed to providing accurate, easy-to-understand content to support pharmacy students and professionals. My aim is to make complex pharmaceutical concepts accessible and useful for real-world application.

Mail- Sachin@pharmacyfreak.com