AQUATIC CHEM QUIZ 3

Question 1

What key processes do micro organisms carry out in water chemistry?

Answer 1

Photosynthesis and respiration

Question 2

What are organic hazardous substances carried through water as?

Answer 2

As emulsions of very small particles suspended in water

Some hazardous materials are deposited in sediments

Question 3

Autotrophic

Answer 3

Use solar/chemical energy to fix elements from simple non-living inorganic material—>complex life molecules that compose living organisms

PRODUCERS

Question 4

Heterotrophic

Answer 4

Use organic substances produced by autotrophs as energy sources & as a raw material for the synthesis of their own biomass

Cannot produce its own food

DECOMPOSERS(bacteria, fungi)

Question 5

The roles of micro organisms in water

Answer 5

1. Oxygen production
2. breakdown of biomass
3. Catalysts of aquatic chemical reactions
   

Question 6

Examples of microorganisms in water

Answer 6

1. Algae
2. fungi
3. bacteria

Question 7

Aerobic

Answer 7

Require molecular oxygen as an electron receptor

Question 8

Facultative bacteria 

Answer 8

Uses free oxygen and other substances as electron receptors

Question 9

Ways other than photosynthesis and respiration that microbes are involved in the C cycle

Answer 9

1. Degradation of biomass
2. Methane production
3. Degradation of hydrocarbons

Question 10

What is Nitrogen fixation

Answer 10

Any natural/ industrial process that causes free nitrogen

Question 11

What is nitrification?

Answer 11

Reduced nitrogen compounds are oxidised to nitrite & nitrate

The conversion of N(-III) to N(V)

2O2 + NH4+ —> NO3- + 2H+ + H2O

Question 12

What is Nitrate reduction?

Answer 12

Nitrate used as an electron acceptor in anaerobic conditions

2NO3- + {CH2O} —> 2NO2- + H2O + CO2

Question 13

What is Denitrification?

Answer 13

A process I converts nitrate to nitrogen gas

End product- N2

Question 14

What are the four trophic classifications of lakes?

Answer 14

1. Oligotrophic - little to no aquatic vegetation
2. Mesotrophic- intermediate productivity
3. Eutrophic- large quantities of organisms (algal blooms)
4. Hypereutrophic- excessive algal growth

OMEH

Question 15

Liebig’s Law of the Minimum states: 

Answer 15

If one of the essential plant nutrient is deficient, plant growth will be poor even when all other essential nutrients are present
or
The yield of a given species should be limited by the nutrient that was present in the least quantity in the environment relative to its demand for growth

Question 16

What are the Key variables for eutrophication?

Answer 16

Sunlight
Nitrogen
Phosphorus

Question 17

TN stands for

TP stands for

Answer 17

Total nitrogen

Total phosphorus

Question 18

Chl a stands for

SD stands for

Answer 18

Chlorophyll a

Secchi disk transparency

Question 19

Factors that can influence eutrophication

Answer 19

Dissolved oxygen
Light
Macronutrients (Ca, Mg, K)
Salinity

Question 20

What is eutrophication?

Answer 20

An enrichment of water by nutrients that cause structural changes to the ecosystem

E.g excessive growth of algae
Depletion of fish species
Deterioration of water quality

Question 21

What does OECD stand for?

Answer 21

Organisation for economic cooperation and development

Question 22

Affects cultural eutrophication is having on water bodies

Answer 22

Cultural eutrophication is caused by humans speeding up the process of natural eutrophication

Causing an abundance of particular substances, e.g. phytoplankton, bacteria, fungi & debris which determines the turbidity of water.

Low biodiversity
Depletion of fish
Low BOD levels

Question 23

Signs of excessive eutrophication

Answer 23

Bad odour
Bad taste
Depletion of fish
Potentially toxic algae 

Question 24

Cause of an excessive amount of nutrients

Answer 24

1.Fertilisers and agricultural run-off
2.Discharge of WASTE WATER


Question 25

Nuisance Harmful Alage or Harmful Algal Blooms (HABS)

Answer 25

No toxins but high biomass

Question 26

Toxic Harmful Alage or Harmful Algal Blooms (HABS)

Answer 26

Those that produced toxins or metabolites harmful to humans/ animals

Question 27

What is a pesticide?

Answer 27

A substance for preventing or destroying pests

Question 28

What techniques/steps are used in water treatment?

Answer 28

1. Pre-treatment 2. Mixing and coagulation 3. Settlement 4. Filtration 5. Disinfection

Question 29

Where is raw freshwater abstracted from?

Answer 29

Rivers, lakes and underground sources to be treated for human consumption

Question 30

What are the objectives of water treatment?

Answer 30

safe for human consumption aesthetically appealing | reasonable cost

Question 31

Public water supplies normally service the requirements of where

Answer 31

Domestic households Industry Commercial

Question 32

What are the two sets of standards for water quality

Answer 32

1. Quality of raw water | 2. Quality of treated water

Question 33

What are the four classes of water treatment?

Answer 33

Class A- no treatment Class B- used for public supplies, disinfected Class C- standard treatment, from lowland areas & reservoirs Class D- when industries require high quality/ source is down stream of urban develpments

Question 34

What processes occur in pre-treatment of water?

Answer 34

``` Screening Raw water storage Aeration Preliminary settling Prechlorination ``` SRAPP

Question 35

Purpose of screening and water treatment

Answer 35

To remove large floating debris and suspended solids (leaves, twigs, plastics) 

Question 36

What three types of screens are used for screening

Answer 36

Bar screens Band and drum screens Micro strainers

Question 37

What is raw water storage?

Answer 37

Practical temporary storage Water usually needs to be stored before treatment Usually stored in reservoirs

Question 38

Benefits of raw water storage

Answer 38

1. Natural settlement occurs 2. Reduction in number of pathogenic bacteria 3. Water quality improves with storage especially relating to suspended solids

Question 39

Benefits of aeration 

Answer 39

1. Improves raw water quality 2. Supplies oxygen 3. Liberates unwanted gases e.g. CO2 4. Cheap process

Question 40

What is Chlorination 

Answer 40

And essential method of disinfection | LAST STAGE of treatment

Question 41

What is prechlorination

Answer 41

Injecting chlorine into raw water straight after abstraction from river Used on water with HIGH BACTERIAL COUNT

Question 42

Why is chlorination still necessary after prechlorination?

Answer 42

Organic matter reacts with chlorine at this stage reducing its effectiveness as a disinfectant

Question 43

Negatives of prechloriantion?

Answer 43

High amount of chlorine needed, moreso than later stage chlorination

Question 44

Example of a coagulant

Answer 44

Ferric chloride

Question 45

Purpose of filtration

Answer 45

To remove fine non-settleable particles from water

Question 46

Name three types of filtration

Answer 46

1. Slow sound filtration 2. Rapid sand filtration 3. Activated carbon

Question 47

Deficiency affiliation depends on

Answer 47

1. The size and shape of the media | 2. Rate flow of water through the filter

Question 48

Limitations of Chlorination 

Answer 48

Chlorination byproducts- potential long term effects taste and odour issues can affect quality  Lower effectiveness in TURBID WATERS

Question 49

Example of chlorination by product

Answer 49

Trihalomethanes

Question 50

What type of water is prechlorination generally used on?

Answer 50

Water with high bacterial count