MCQ Bank

Bioventing is generally less suitable when the water table is very close to the ground surface because limited unsaturated soil remains available for air movement. A water table within about 2.0 m of the surface can significantly restrict effective bioventing.

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Q41

In----------technique air extraction rate is adjusted to maximize underground decomposition.

A) Biosparging
B) Injection Recovery
C) All of the above
D) Bioventing

AI Explanation

Bioventing controls the rate of air extraction or injection to optimise oxygen supply and stimulate microbial degradation in the unsaturated soil zone. The airflow is adjusted to promote underground biodegradation.

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Q42

----------technique is used to remediate contamination above the boundary of the water table.

A) All of the above
B) Biosparging
C) Injection Recovery
D) Bioventing

AI Explanation

Bioventing is primarily used to remediate contamination in the unsaturated zone above the water table. It supplies oxygen to stimulate aerobic microorganisms that degrade contaminants.

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Q43

Some plants act as pumps or siphons, removing contaminants from the----------.

A) Air
B) Soil
C) All of the above
D) Water

AI Explanation

Certain plants can act as biological pumps, taking up contaminants from contaminated soil through their roots. This phytoremediation process can accumulate or transform contaminants within plant tissues.

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Q44

---------method makes use of the movement of ground water through the zone of contamination to assist the remediation process.

A) Bioventing
B) Injection Recovery
C) All of the above
D) Biosparging

AI Explanation

Injection-recovery methods use the movement of groundwater through a contaminated zone to assist in transporting and recovering contaminants. This controlled groundwater flow can enhance the remediation process.

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Q45

Pteris vittata, accumulates -------percentage of arsenic.

A) 4.5%
B) 2.3%
C) 3.4%
D) 1.2%

AI Explanation

Pteris vittata is a well-known arsenic hyperaccumulator and can accumulate about 2.3% arsenic in its frond biomass. This exceptional accumulation ability makes it useful for phytoremediation of arsenic-contaminated soils.

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Q46

Hyperaccumulators have ability to absorb large amounts of metals typically______more as compared to most ordinary plants.

A) 30-50 times
B) 100-150 times
C) 50–100 times
D) 20-30 times

AI Explanation

Hyperaccumulator plants can absorb and concentrate metals at levels far exceeding those of ordinary plants. In many educational references, this capacity is described as roughly 100–150 times greater.

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Q47

The technique which choose and permit plants to grow for a suitable length of time.

A) Rhizofiltration
B) Phytoextraction
C) Bioaccumulation
D) All of the above

AI Explanation

Phytoextraction involves growing selected plants for a suitable period so they absorb contaminants from soil and accumulate them in harvestable tissues. The plants are then harvested to remove the contaminants from the site.

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Q48

Bio accumulation takes place by--------.

A) None of above
B) Microbes
C) Plant species
D) Both A & B

AI Explanation

Bioaccumulation in phytoremediation commonly refers to the uptake and accumulation of contaminants within plant tissues. Plant species capable of accumulating metals can therefore be used for this purpose.

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Q49

Which of the following technique is used to remediate contamination at, or below, the water table boundary?

A) Injection Recovery
B) Biosparging
C) All of the above
D) Bioventing

AI Explanation

Biosparging introduces air or oxygen below the water table to stimulate aerobic microbial activity and contaminant degradation. It is therefore suited to remediation at or below the water-table boundary.

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Q50

which of the following best describes contaminant?

A) Should not dissolve
B) Rarely available
C) Low to medium toxicity range
D) High toxicity range

AI Explanation

A contaminant is generally a substance present in an environment at an undesirable level and capable of causing harm. In the context of bioremediation, contaminants are often characterized by their potentially high toxicity to organisms or ecosystems.

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Q51

-----speeds up the natural ability of resident microbes to metabolize the pollutant?

A) Removal of oxygen
B) Dissolving oxygen in water
C) All of the above
D) Addition of oxygen

AI Explanation

Adding oxygen can stimulate aerobic microorganisms and increase their ability to metabolize pollutants. Oxygen availability is therefore an important factor in enhancing natural microbial biodegradation.

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Q52

For efficient bioremediation the suitable temperature should be ----------------.

A) -20 ◦C
B) 60-70 ◦C
C) 20-30 ◦C
D) 95 ◦C

AI Explanation

Most microorganisms involved in effective bioremediation have good metabolic activity at moderate temperatures. A temperature range of about 20–30 °C is generally suitable for microbial degradation.

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Q53

Two indica rice cultivars MORETSU and IR-8 are used for extraction of -----------------------.

A) Copper
B) Nickel
C) Cadmium
D) Zinc

AI Explanation

The indica rice cultivars MORETSU and IR-8 have been studied for their ability to take up and accumulate cadmium. Their uptake capacity makes them relevant to phytoremediation of cadmium-contaminated environments.

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Q54

In which of the following technique of bioremediation, contaminant is used as a food source by the microbes?

A) Co- metabolism
B) None
C) Immobilization
D) Mineralization

AI Explanation

Mineralization is the microbial breakdown of an organic contaminant into simpler inorganic end products, with the contaminant serving as a substrate or food source. This differs from co-metabolism, where degradation occurs without the contaminant serving as the primary growth substrate.

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Q55

Which of the following technique involves introducing oxygen and nutrients to the contaminated area by various methods?

A) Ex situ techniques
B) Both
C) None
D) In situ Techniques

AI Explanation

In situ bioremediation treats contamination at the original site without excavating or removing the contaminated material. Oxygen and nutrients can be introduced into the contaminated area to stimulate microbial activity and pollutant degradation.

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Q56

-----------plant species can be used as terrestrial phyto-systems.

A) 100
B) 300
C) 400
D) 200

AI Explanation

Approximately 400 plant species have been identified as suitable for use in terrestrial phyto-systems. These plants can help remove, stabilize, or transform contaminants in soil.

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Q57

Bioremediation relies on the inherent abilities and characteristics of following --------- species.

A) Fungi
B) All of the above
C) Plant species
D) Indigenous bacteria

AI Explanation

Bioremediation can rely on the natural abilities of indigenous bacteria, fungi, and plant species. These organisms can degrade, transform, immobilize, or accumulate different environmental contaminants.

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Q58

Some other plants species enable the biodegradation of relatively large--------.

A) Inorganic molecules
B) Organic molecules
C) Heavy metals
D) Soil particles

AI Explanation

Some plant species can enhance the biodegradation of relatively large organic molecules through plant-associated microorganisms and enzymatic processes. This makes them useful in phytoremediation of organic contaminants.

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Q59

Which of the following methods is considered as an effective biological water treatment method?

A) Natural attenuation
B) Bio attenuation
C) Passive remediation
D) All of the above

AI Explanation

Natural attenuation, bioattenuation, and passive remediation are biological approaches that can be used to treat contaminated water under suitable conditions. They rely on natural or enhanced biological processes to reduce contaminant concentrations.