Chapter 1 Flashcards
Acidity of water is
its quantitative capacity to react with a strong base to a designated pH.
Acidity is a measure of
an aggregate property of water
Acidity is a measure of an aggregate property of water and can be interpreted in terms of
specific substances only
Alkalinity is also known as
the buffering capacity of a stream
alkalinity refers
how well it can neutralize acidic pollution and resist change in PH
alkalinity measures
the amount of alkaline compounds in the water, such as carbonate, bicarbonates and hydroxides. these compounds are natural buffers that can remove excess hydrogen, or H+, ions
BOD means
The Biological Oxygen Demand
BOD means
the amount of oxygen consumed by bacteria in the decomposition of organic material.
BOD also includes
the oxygen required for the oxidation of various chemical in the water, such as sulfides, ferrous iron and ammonia.
dissolved oxygen test tells you
how much oxygen is available
BOD test tells you
how much oxygen is being consumed
BOD is determined by
measuring the dissolved oxygen level in a freshly collected sample and comparing it to the dissolved oxygen level in a sample that was collected at the same time but incubated under specific conditions for a certain number of days.
The difference in the oxygen readings between the two samples in the BOD is recorded in units of
mg/L
Unpolluted, natural waters should have a BOD of
5 mg/L or less
Raw sewage may have BOD levels ranging from
150 – 300 mg/L
conductivity is
a measure of how well water can pass an electrical current. It is an indirect measure of the presence of inorganic dissolved solids such as chloride, nitrate, sulfate, phosphate, sodium, magnesium, calcium, iron and aluminum.
It is an indirect measure of the presence of inorganic dissolved solids such as chloride, nitrate, sulfate, phosphate, sodium, magnesium, calcium, iron and aluminum. The presence of these substances increases
the conductivity of a body of water.
…………………………..like …………………………………………..do not conduct electricity very well, and thus have a ……………….conductivity in water.
Organic substances
oil, alcohol, and sugar
low
Inorganic dissolved solids are essential ingredients for
aquatic life
Inorganic dissolved solids are essential ingredients for aquatic life. They
regulate the flow of water in and out of organisms’ cells and are building blocks of the molecules necessary for life.
A high concentration of dissolved solids, however, can cause
water balance problems for aquatic organisms and decrease dissolved oxygen levels
Temperature: Oxygen is more easily dissolved in
cold water
Flow: Oxygen concentrations vary with
the volume and velocity of water flowing in a stream.
Usually streams with ……………………………………………………. are considered healthy streams.
high dissolved oxygen concentrations (greater than 8 mg/L for Ozark streams)
Usually streams with high dissolved oxygen concentrations (greater than 8 mg/L for Ozark streams) are considered healthy streams. They are able to support a greater
diversity of aquatic organisms
They are able to support a greater diversity of aquatic organisms. They are typified by
cold, clear water, with enough riffles to provide sufficient mixing of atmospheric oxygen into the water.
In streams that have been impacted by any of the above factors, summer is usually the
most crucial time for dissolved oxygen levels because stream flows tend to lessen and water temperatures tend to increase.
In general, DO levels less than ………are stressful to most aquatic organisms.
3 mg/L
Most fish die at
1-2 mg/L
Most fish die at 1-2 mg/L. However, fish can move away from
low DO areas
Water with low DO from ……………………….are considered hypoxic
2 – 0.5 mg/L
waters with ………………………….are anoxic.
less than 0.5 mg/L
Because the temperature of the stream can vary daily, and even hourly, it is important to
factor out the effect of temperature when analyzing the DO levels in a sample of water.
Because the temperature of the stream can vary daily, and even hourly, it is important to factor out the effect of temperature when analyzing the DO levels in a sample of water. This is achieved by
considering the saturation value.
This is achieved by considering the saturation value. Saturation is
the maximum level of DO that would be present in the water at a specific temperature, in the absence of other influences.
Once you know the temperature of the water in your stream you can use an oxygen saturation table to
determine the maximum DO concentration
if your stream temperature is 8 degrees C, your maximum saturation value would be 11.83 mg/L. If your DO reading was 8.5 mg/L, your percent saturation would be
8.50/11.83=71.9 percent
Since a healthy stream is considered to be ………………….percent saturated,
90-100
your sample indicates that something else besides temperature is affecting oxygen levels adversely (examples:………………………………….)
suspended or dissolved solids, or bacteria decomposition
Fecal Coliform
Human and animal wastes carried to stream systems are sources of pathogenic or disease-causing, bacteria and viruses. The disease causing organisms are accompanied by other common types of nonpathogenic bacteria found in animal intestines, such as fecal coliform bacteria, enterococci bacteria, and escherichia coli, or E. coli bacteria.
Fecal coliform, enterococci, and E. coli bacteria are
not usually disease-causing agents themselves.
Fecal coliform, enterococci, and E. coli bacteria are not usually disease-causing agents themselves. However, high concentrations suggest the
presence of disease-causing organisms
Fecal coliform, enterococci, and E. coli bacteria are used as
indicator organisms
ecal coliform, enterococci, and E. coli bacteria are used as indicator organisms; they indicated
the probability of finding pathogenic organisms in a stream.
To measure indicator bacteria
water samples must be collected in sterilized containers. The samples are forced through a filter and incubated at a specific temperature for a certain amount of time. The resulting colonies that form during incubation are counted and recorded as the number of colony producing units per 100 mL of water
Hardness is
frequently used as an assessment of the quality of water supplies. The hardness of a water is governed by the content of calcium and magnesium salts (temporary hardness), largely combined with bicarbonate and carbonate and with sulfates, chlorides, and other anions of mineral acids (permanent hardness)
The effects of metals in water and wastewater range from
beneficial through troublesome to dangerously toxic.
Some metals are essential, others may
adversely affect water consumers, wastewater treatment systems, and receiving waters.
Some metals may be either beneficial or toxic, depending on
concentration
The primary mechanism for toxicity to organisms that live in the water column is by
absorption to or uptake across the gills
The primary mechanism for toxicity to organisms that live in the water column is by absorption to or uptake across the gills: this physiological process requires
metal to be in a dissolved form
this physiological process requires metal to be in a dissolved form. This is not to say that particulate metal is nontoxic, only that particulate metal
appears to exhibit substantially less toxicity than does dissolved metal
Dissolved
hose metals of an unacidified sample that pass through a 0.45 micrometer membrane filter and is thought to better represent the bioavailable fraction of metal in the water column than does total recoverable metal
Recoverable
Those metals that are not tightly bound and are biologically available to aquatic organisms
Total:
Includes all metals, inorganically and organically bound, both dissolved and particulate. Will give a unrealistic high value of those metals that are biological available to aquatic organisms.
Not all metals are acutely toxic in small concentrations. The…………………………….. include ……………………………………………………………are the most toxic to aquatic organisms.
“heavy metals”
copper, or Cu, iron, or Fe, cadmium, or Cd, zinc, or Zn, mercury, or Hg, and lead, or Pb, and
Some water quality characteristics which affect metal toxicity include
temperature, pH, hardness, alkalinity, suspended solids, redox potential and dissolved organic carbon.
Metals can bind to many ……………………………………….which ……………………………….
organic and inorganic compounds
reduces the toxicity of the metal.
Nitrogen is important to
to all life
Nitrogen in the atmosphere or in the soil can go through
many complex chemical and biological changes
Nitrogen in the atmosphere or in the soil can go through many complex chemical and biological changes. It can be combined into
living and non-living material and return back to the soil or air in a continuing cycle called the nitrogen cycle.
Nitrogen occurs in natural waters in various forms, including
including nitrate, or NO3, nitrite, or NO2, and ammonia, or NH3.
Ammonia, or
NH3
Ammonia, or NH3: It is
one of the most important pollutants in the aquatic environment
Ammonia, or NH3: It is one of the most important pollutants in the aquatic environment because
of its relatively highly toxic nature and its ubiquity in surface water systems.
It is one of the most important pollutants in the aquatic environment because of its relatively highly toxic nature and its ubiquity in surface water systems. It is discharged in large quantities in
in industrial, municipal and agricultural waste waters.
Nitrate, or
NO3
Nitrate, or NO3-: Generally occurs in
trace quantities in surface water
Nitrate, or NO3-: Generally occurs in trace quantities in surface water. It is the essential
nutrient for many photosynthetic autotrophs and has been identified as the growth limit nutrient.
Nitrate
It is only found in
small amounts in fresh domestic wastewater,
Nitrate
It is only found in small amounts in fresh domestic wastewater, but in effluent of
nitrifying biological treatment plants.
Nitrate is a less serious environmental problem, it can be found in relatively high concentrations where it is
relatively nontoxic to aquatic organisms
When nitrate concentrations become excessive, however, and
other essential nutrient factors are present, eutrophication and associated algal blooms can be become a problem
Nitrite, or
NO2
Nitrite is
extremely toxic to aquatic life
Nitrite is extremely toxic to aquatic life, however, is
usually present only in trace amounts in most natural freshwater systems because it is rapidly oxidized to nitrate.
In sewage treatment plants using
nitrification process to convert ammonia to nitrate, the process may be impeded, causing discharge of nitrite at elevated concentrations into receiving waters.
The conversion process is affected by several factors, including
pH, temperature and dissolved oxygen, number of nitrifying bacteria and presence of inhibiting compounds.
Organic nitrogen and ammonia can be
determined together and have been referred to as “Kjeldahl nitrogen, or TKN,”
Organic nitrogen and ammonia can be determined together and have been referred to as “Kjeldahl nitrogen, or TKN,” a term that
reflects the technique used in their determination.
Organic Nitrogen:
It is the byproduct of living organisms
Organic Nitrogen: It is the byproduct of living organisms. It includes
such natural materials as proteins and peptides, nucleic acids and urea, and numerous synthetic organic materials.
Phosphorus is often the
limiting nutrient for plant growth, meaning it is in short supply relative to nitrogen.
Phosphorus usually occurs in
nature as phosphate
Phosphorus usually occurs in nature as phosphate, which is a
phosphorous atom combined with four oxygen atoms
which is a phosphorous atom combined with four oxygen atoms, or
PO4-3
organic phosphate
Phosphate that is bound to plant or animal tissue
inorganic phosphate
Phosphate that is not associated with organic material
Phosphorus
Both forms are present in aquatic systems and may be
either dissolved in water or suspended (attached to particles in the water column).
Inorganic phosphate is often referred to as
orthophosphate or reactive phosphorous
Inorganic phosphate is often referred to as orthophosphate or reactive phosphorous. It is the form ………………………………………., and thus
most readily available to plants, and thus may be the most useful indicator of immediate potential problems with excessive plant and algal growth
pH is
an important limiting chemical factor for aquatic life
pH is an important limiting chemical factor for aquatic life. If the water in a stream is …………………………………… the ……………………………………………….. may disrupt ……………………………………….
is too acidic or basic, the H+ or OH- ion activity may disrupt aquatic organisms biochemical reactions
pH is an important limiting chemical factor for aquatic life. If the water in a stream is too acidic or basic, the H+ or OH- ion activity may disrupt aquatic organisms biochemical reactions by
either harming or killing the stream organisms.
pH is expressed in a scale with ranges from
1 to 14
A solution with a pH less than 7 has
more H+ activity than OH-
. A solution with a pH less than 7 has more H+ activity than OH-, and is considered
acidic
A solution with a pH value greater than 7 has
more OH- activity than H+, and is considered basic
The pH scale is …………., meaning
logarithmic, meaning that as you go up and down the scale, the values change in factors of ten.
A one-point pH change indicates the
strength of the acid or base has increased or decreased tenfold.
Streams generally have a pH values ranging between
Streams generally have a pH values ranging between 6 and 9, depending upon
the presence of dissolved substances that come from bedrock, soils and other materials in the watershed.
Changes in pH can change the
aspects of water chemistry
Changes in pH can change the aspects of water chemistry. For example,
as pH increases, smaller amounts of ammonia are needed to reach a level that is toxic to fish.
As pH decreases
the concentration of metal may increase because higher acidity increases their ability to be dissolved from sediments into the water
Total Solids is a measure of
the suspended and dissolved solids in a body of water.
Total Solids is a measure of the suspended and dissolved solids in a body of water. Thus, it is related to
both conductivity and turbidity
Water Temperature is a
controlling factor for aquatic life
Water Temperature is a controlling factor for aquatic life: it controls
the rate of metabolic activities, reproductive activities and therefore, life cycles.
If stream temperatures increase, decrease or fluctuate too widely, ……………….. may
metabolic activities may speed up, slow down, malfunction, or stop altogether.
There are many factors that can influence the stream temperature. Water temperatures can fluctuate
seasonally, daily, and even hourly, especially in smaller sized streams.
Water temperatures can fluctuate seasonally, daily, and even hourly, especially in smaller sized streams. Spring
discharges and overhanging canopy of stream vegetation provides shade and helps buffer the effects of temperature changes.
Water temperature is also influenced by
the quantity and velocity of stream flow
The sun has
much less effect in warming the waters of streams with greater and swifter flows than of streams with smaller, slower flows.
Temperature affects the
concentration of dissolved oxygen in a water body.
TEMPERATURE
Oxygen is more easily dissolved in
cold water
Turbidity is a measure of
the cloudiness of water
Cloudiness is caused by
suspended solids (mainly soil particles) and plankton (microscopic plants and animals) that are suspended in the water column.
Moderately low levels of turbidity may indicate
a healthy, well-functioning ecosystem, with moderate amounts of plankton present to fuel the fuel the food chain.
Moderately low levels of turbidity may indicate a healthy, well-functioning ecosystem, with moderate amounts of plankton present to fuel the fuel the food chain. However, higher levels of turbidity
pose several problems for stream systems.
Turbidity blocks out
the light needed by submerged aquatic vegetation
. Turbidity blocks out the light needed by submerged aquatic vegetation. It also can raise
raise surface water temperatures above normal because suspended particles near the surface facilitate the absorption of heat from sunlight.
Suspended soil particles may carry
nutrients, pesticides, and other pollutants throughout a stream system, and they can bury eggs and benthic critters when they settle.
Turbid waters may also be low in
dissolved oxygen
High turbidity may result from
sediment bearing runoff, or nutrients inputs that cause plankton blooms.
