Drinking Water Quality Evaluation
water tests , Water Quality Control Indicators
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Language: en
Added: Oct 13, 2024
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Slide Content
Drinking Water Quality Drinking Water Quality
EvaluationEvaluation
Water Quality
Control
Indicators
Sample collection
During sample collection:
" Collection details
# Date and time of collection
# Name of collector)
# Place of origin /
# Sampling point/addresses (roadside stall, farm, market)
# Condition of cultivation (feed regime, altitude, irrigation)
# Purchase price /
# Graphical record (Photograph, visual record with scale)
# Transport conditions ( mode and conditions of transport)
Sample collection
Things to note
# Deliver samples to the laboratory promptly with
the original
conditions maintained as nearly as possible
# If products are in bulk: storage procedures, choice of
containers, modes of transport should be considered
# Use containers that are clean, dry, leak-proof, widemouthed, sterile, and of a
size suitable for samples of the product.
Sampling Collection
Things to note ا
Population
Samples
.1
:Temperature
:Turbidity
Turbidity is a measurement of how cloudy the water is in a lake
or river. Anything that makes water cloudy will increase
turbidity. High turbidity can be caused by silt, mud, algae,
plant pieces, melting glaciers, sawdust, wood ashes or
chemicals in the water.
Most of the natural river water is clear,
but if there are more algae in the water, the river
looks green. Water looks blue when containing
more calcium carbonate,
looks red with more sulfur, and looks black
with more mud. Industrial pollution also changes
the river colors
Perhaps the most common cause of water color is the
presence minerals.
Red and brown colors are due to iron; black to manganese or organic
matter; and yellow to dissolved organic matter such as رفصعلا
tannins. Iron
and manganese are common, at least in small amounts, in most rocks
and
sedimentary
2. Pretreatment for Turbidity Removal To determine color by currently accepted methods,
turbidity must be removed before analysis. Methods for removing turbidity without removing
color vary. Filtration yields results that are reproducible from day to day and among laboratories
:Taste & Oder
Chemical Indicators for water
quality
Physical, chemical, and biological properties define the quality status of water
which further indicates the suitability for a specific use.
The physical properties of water include
turbidity,
temperature,
total dissolved solids (TDS),
color,
odor,
conductivity,
salinity,
and dissolved oxygen (DO),
chemical characteristics include
pH,
chlorides,
fluorides,
organic contaminants
and heavy metals among other pollutants
biological parameters include
bacteria,
algae, virus load and fecal matter
.1
:Chemical Indicators for water quality
pH is a measure of how acidic/basic
water is. The range goes from 0 to
14, with 7 being neutral. pHs of less
than 7 indicate acidity, whereas a
pH of greater than 7 indicates a
base. pH is really a measure of the
relative amount of free hydrogen
and hydroxyl ions in the water.
Europe, Poland, Germany, Czech Republic, Sweden, Norway and Finland are
affected because of British and European factories. In Asia, India and China are
mostly affected mainly because of the large number of factories.
European emissions of sulphur dioxide (SO2—black), nitrogen oxides (NOx, calculated as NO2—
green) and ammonia (NH3—blue)
He pointed to the significant decrease in pH of rainwater and surface waters that had
occurred over the previous decade and linked it to the large and increasing emissions of
sulphur dioxide in Europe
Elevated pH in ponds also favors the growth of blue-green algae (called
cyanobacteria by many biologists), because these organisms tend to grow
better than other kinds of algae at a high pH. Aquaculture ponds often have
phytoplankton communities in which one or a few species of blue-green algae
make up 90 percent or more of the algal community.
: Total Dissolved Solids (TDS)
What is TDS in Water? TDS stands for Total
Dissolved Solids and refers to the total
concentration of dissolved substances in
drinking water. TDS comprises inorganic salts
and a small amount of organic matter as well.
TDS majorly includes species such as sodium, potassium, magnesium,
calcium, strontium, barium, iron, aluminum, bicarbonate, chloride and
sulfates [3,15,21,22]. Trace elements can also be present such as dissolved
metals, metalloids and boron [23,24]. Saline water can cause physiological
effects in humans and livestock through consumption [25]. Also, elevated TDS
concentrations in irrigation waters may cause adverse effects on plants and
crops by inducing saline soils [25].
Physiological effects refer to the physical changes and symptoms experienced by adult
patients after discharge from the hospital, such as lethargy, weakness, pain, and
difficulties with mobility, swallowing, and eating.
Ion Chromatography InstrumentIon chromatography (IC) systems separate
charged particles from a liquid and measure their concentration. IC systems
can analyze particles such as anions, cations, organic salts, and proteins.
They are used in environmental, manufacturing, food, pharmaceutical, and
chemical industries.
Water Alkalinity
TDS-EC relationship:
TDS (mg/L) = ke × EC (μS/cm)
where ke is a constant of proportionality.
.1
: Conductivity
Ca(OH)
₂
NaHCO
₃
Temperature affects the conductivity of
solutions and metals, because of the
effect it has on the viscosity of solutions
and the nature of ions. When
temperature changes, so does
conductivity; conductivity invariability
increases when temperature increases.
:Water Hardness
Hard water is usually defined as water, which
contains a high concentration of calcium and
magnesium ions. However, hardness can be
caused by several other dissolved metals;
those forms divalent or multivalent cations,
including aluminum, barium, strontium,
iron, zinc, and manganese.
When using hard water, more soap or detergent is needed to get
things clean, be it your hands, hair, or your laundry
When hard water is heated, such as in a home water heater,
solid deposits of calcium carbonate can form. This scale can
reduce the life of equipment, raise the costs of heating the
water, lower the efficiency of electric water heaters, and
clog pipes
:chlorides
(Cl
-
)
.Chloride is present in natural water in the form of sodium,
calcium, and magnesium salts. Cl
−
is widely distributed in
natural water and is present in almost all surface waters, but
the content varies widely from 10 to 20 mg/L in river water to
19,000 mg/L in seawater.
The Chloride Ion-Selective Electrode (ISE) is used to measure the
concentration of Chloride (Cl
–
) in aqueous samples. The
concentration of the Chloride ion gives a quick measurement of
salinity of water samples. Use the Chloride ISE to measure chloride
levels in ocean saltwater or salt in food samples.
An
ion-selective electrode
(
ISE), also known as a
specific ion electrode
(
SIE), is
a
transducer
(or
sensor) that converts the change in the concentration of a specific
ion
dissolved in a
solution
into an electrical
potential. The voltage is theoretically
dependent on the
logarithm
of the ionic activity,
.1
sulfates (SO4
2-
)
Elevated sulfate levels in water may have a laxative effect that
can lead to dehydration, and is mostly a concern for infants. High
sulfate levels can be a result of sulfur oxidizing bacteria present in
the water supply
To be safe, only use water with a sulfate level lower than 500 milligrams per liter
(mg/L)
.1
:Ammonia (NH4
+
)
Natural processes can cause
low levels of nitrate in
drinking water—usually less
than 3 mg/L. The health
concern is with levels of
nitrate over 10 mg/L. High
levels of nitrate in water can
be a result of runoff or
leakage from fertilized soil,
wastewater, landfills,
animal feedlots, septic
systems, or urban
drainage.
1.
: Nitrate (NO3
-
) and Nitrite (NO2
-
)
Methemoglobin is a form of hemoglobin.
With methemoglobinemia, the hemoglobin
can carry oxygen, but is not able to release it
effectively to body tissues.
Nitrite is of particular health concern in the body because it causes the
hemoglobin in the blood to change to methemoglobin. Methemoglobin
reduces the amount of oxygen that can be carried in the blood. This results in
cells throughout the body being deprived of sufficient oxygen to function
properly.
.1
: Dissolved Oxygen (DO)
6H2O + 6CO2 + light energy→ 6O2 +C6H12O6.
Mechanical aeration increases the rate of loss of oxygen from ponds when the water is supersaturated with this gas, and it can
also be used to prevent and manage dissolved oxygen levels. Photo by Darryl Jory.
What You Need to Know About Coliform Bacteria in Drinking Water
Coliform bacteria are one of the most common water contamination problems in
private water systems in the U.S.
Coliform is a family of bacteria common in soil, plants, and intestinal tracts of
humans and animals.
The presence of these bacteria in drinking water is used to determine if it may
be unsafe to drink.
A recent study of the results from testing for bacteria in drinking water i:
About two out of three springs had total coliform present.
One in three wells had total coliform present.
One in 10 families with a spring is drinking water contaminated with E. coli
bacteria that can cause diarrhea and other gastrointestinal diseases.