Measurements and Standards

Question 1

what are the environmental standards

Answer 1

standards or methods or requirements for land use and subdivision, use of coastal marine area and beds of lakes and rivers, water take and use, discharges, or noise. + monitoring

Question 2

NZ drinking water standards

Answer 2

max acceptable value for drinking water - the concentration of a determinand below which the presence of the determinand does not result in any significant risk to a consumer over a lifetime of consumption

Question 3

fresh water for pH criterea

Answer 3

6.5-9.5

Question 4

drinking water pH critera

Answer 4

6.5-8.5

Question 5

what does pH measure

Answer 5

hydrogen ion concentration

Question 6

how do you measure pH

Answer 6

negative log of hydrogen ion concentration

Question 7

what does pH in water control

Answer 7

solubility of metals (lead is bad for you)

Question 8

what is alkalinity made up of

Answer 8

2 ions carbonate CO3 2- and bicarbonate HCO3-

Question 9

what is alkalinity

Answer 9

acid neutralizing capacity of the water

Question 10

how is alkalinity measured

Answer 10

by measuring the amount of acid (sulfric acid needed to bring the sample to a pH of 4.2)

Question 11

what does conductivity measure

Answer 11

electric conductivity of water

Question 12

higher value of conductivity means water is a

Answer 12

better electrical conductor

Question 13

how does electrical conductivity increase

Answer 13

when more salt (sodium chloride) is dissolved in water

Question 14

what is conductivity an indirect measurement of

Answer 14

salinity

Question 15

what are the units of conductivity

Answer 15

µmhos/cm at 25C or µsiemens/cm

Question 16

what is the purity of water defined as

Answer 16

how resistive it is to electric conductivity

Question 17

what is salinity

Answer 17

classification of ground water

Question 18

what is salinity based on

Answer 18

composition on total dissolved solids content

Question 19

what type of water can we not drink

Answer 19

water over 1000 mg/l dissolved salt content

Question 20

what is dissolved oxygen

Answer 20

amount of gaseous oxygen dissolved in water

Question 21

how does oxygen get into the water

Answer 21

diffusion from surrounding air, aeration, photosynthesis

Question 22

how much oxygen do we need to support a diverse population

Answer 22

5-6 mg/l

Question 23

what happens when dissolved oxygen levels <2 mg/l

Answer 23

Hypoxia

Question 24

what is hypoxia

Answer 24

low or depleted amounts of dissolved oxygen. the bloom of algae, organic matter flourishes, lots of bacteria that eats organic matter and consume a lot of oxygen. dissolved oxygen falls below 2 mg/l = death of organic life

Question 25

how does temperature affect water

Answer 25

it is a pollutant of water. If you increase the temperature of water, you are getting rid of gas oxygen, dissolved oxygen. aquatic life suffers because of the less amount of oxygen thats present

Question 26

what does turbidity measure

Answer 26

estimates light scattering by suspended particles

Question 27

the more turbid the water

Answer 27

the more muddy the water is

Question 28

high turbid water or prolonged exposure of aquatic species like fish have..

Answer 28

various health effects and even death at certain high concentrations and exposure over high durations

Question 29

what instrument do we used to measure turbidity

Answer 29

nephelometer

Question 30

how does a nephelometer work

Answer 30

measures scattered light at right angles to the source

Question 31

what is a visible indicator of the presence of solids in a water sample

Answer 31

turbidity

Question 32

how is solids used in water analysis

Answer 32

refers to residue left upon evaporation and may be dissolved or undissolved species

Question 33

how is dissolved solids determined

Answer 33

evaporating water and drying the material at 100C. The mass of remaining solids relative to the volume of water evaporated is the measure

Question 34

what compounds make up total solids

Answer 34

everything that doesnt evaporate below 110C. Examples include: inorganic salts, organic material, insoluble salts, soluble salts, metal etc

Question 35

what are undissolved solids responsible for

Answer 35

turbidity or sediment, isolated by simply filtering

Question 36

what are dissolved solids responsible for

Answer 36

hardness of water. Specifically refers to samples isolated by drying at 180C which removes any bound water.

Question 37

what are volatile solids

Answer 37

solids that will burn off at 550C of lower. Includes the vast majority of organic compounds

Question 38

what are fixed solids

Answer 38

solids remaining after burning at 550C and consist largely of inorganic salts. These salts are most directly related to hardness

Question 39

what are settleable solids

Answer 39

solids that will form sediment if not stirred up. Can be determined by simply allowing the material to sit in an Imhoff cone for an hour

Question 40

how to classify water (3)

Answer 40

- compare irons with ions using chemical equivalence - making sure anions and cations balance - use of diagrams and models

Question 41

why do we do water classifications (4)

Answer 41

- help define origin of the water - indicates residence time in the aquifer - aids in defining the hydrogeology - defines suitability

Question 42

how to find equivalent concentration

Answer 42

concentration/(formula weight/charge)

Question 43

chemical equivalence

Answer 43

going from mg/L -> mmoles/L -> meq/L

Question 44

what diagrams can chemical equivalence be plotted on

Answer 44

piper, stiff, pie, depth profile

Question 45

what are piper diagrams

Answer 45

two ternary diagrams projected on quadralinear diagram

Question 46

what are stiff diagrams and how do they work

Answer 46

concentrations of cations are plotted to the left of the vertical axis and anions are plotted to the right (meq/L). The points are connected to form a polygon. Water of similar quality have distinctive shapes.

Question 47

What is hardness defined as

Answer 47

presence of DIVALENT CATIONS (2+)

Question 48

what does hardness cause

Answer 48

water to form scales and a resistance to soap. Hard water doesn't produce lather with soap solutions, but instead produces white precipitate

Question 49

CaCO3 0-75

Answer 49

soft

Question 50

CaCO3 75-150

Answer 50

moderately hard

Question 51

CaCO3 150-300

Answer 51

hard

Question 52

CaCO3 over 300

Answer 52

very hard

Question 53

how is hardness caused in most natural waters

Answer 53

primarily by compounds of calcuim (ca2+) and magnesium (Mg2+)

Question 54

what is the total hardness

Answer 54

sum of carbonate and non carbonate hardness

Question 55

how is hardness calculated

Answer 55

hardnes as CaCO3 = M2+ x 50 (100 is normal but bc theres 2, 100/2 = 50) / EW of M2+ (EW = equivalent weight)

Question 56

How is hardness calculated using titrimetric method

Answer 56

based on a colorimetric reaction that occurs when all hardness ions have been removed from the solution

Question 57

what is hardness mostly

Answer 57

calcium and magnesium

Question 58

non carbonated hardness is only possible if

Answer 58

alkalinity is lower than calcium magnesium concentrations. if not then non carbonated hardness = 0

Question 59

what is the optimum temperature for drinking water

Answer 59

10-15C

Question 60

Dissolved oxygen concentrations are more in

Answer 60

colder water

Question 61

at higher temperatures, the rate of biological activity is

Answer 61

higher if organics are present in the water

Question 62

what does temperature in water affect

Answer 62

various treatment process, especially during wastewater treatment

Question 63

what does taste and odor indicate

Answer 63

contamination as these are the indicators of organics and inorganic compounts

Question 64

how to work out taste and odor

Answer 64

(volume of sample + volume of pure water added to make the sample odor free) / volume of sample