كيفية اجراء تحاليل المياه/water quality parameters

-
________________________________________
Water Quality Monitoring - A How To Guide -
________________________________________
-
Description Of Water Quality Parameters
-
pH Parameter
pH, or the "potential of hydrogen", is a measure of the concentration of hydrogen ions in the water. This measurement indicates the acidity or alkalinity of the water. On the pH scale of 0-14, a reading of 7 is considered to be "neutral". Readings below 7 indicate acidic conditions, while readings above 7 indicate the water is alkaline, or basic. Naturally occurring fresh waters have a pH range between 6 and 8. The pH of the water is important because it affects the solubility and availability of nutrients, and how they can be utilized by aquatic organisms.
-
Dissolved Oxygen Parameter
Dissolved oxygen is the amount of oxygen dissolved in water, measured in milligrams per liter (mg/L). This component in water is critical to the survival of various aquatic life in streams, such as fish. The ability of water to hold oxygen in solution is inversely proportional to the temperature of the water. For example, the cooler the water temperature, the more dissolved oxygen it can hold.
-
Biological Oxygen Demand (BOD) Parameter
Biological Oxygen Demand is a measure of how much oxygen is used by microorganisms in the aerobic oxidation, or breakdown of organic matter in the streams. Usually, the higher the amount of organic material found in the stream, the more oxygen is used for aerobic oxidation. This depletes the amount of dissolved oxygen available to other aquatic life. This measurement is obtained over a period of five days, and is expressed in mg/L.

Temperature Parameter
Temperature is a measure of how cool or how warm the water is, expressed in degrees Celsius (C). Temperature is a critical water quality parameter, since it directly influences the amount of dissolved oxygen that is available to aquatic organisms. Water temperature that exceeds 18 degrees Celsius (for Class A Waters) has a deleterious effect on several fish species in streams. Salmonids, for example, prefer waters of approximately 12 to 14 degrees Celsius
-
Conductivity Parameter
Conductivity is the ability of the water to conduct an electrical current, and is an indirect measure of the ion concentration. The more ions present, the more electricity can be conducted by the water. This measurement is expressed in microsiemens per centimeter (uS/cm) at 25 degrees Celsius.
-
Total Dissolved Solids (TDS) Parameter
Total dissolved solids is a measure of the amount of particulate solids that are in solution. This is an indicator of nonpoint source pollution problems associated with various land use practices. The TDS measurement should be obtained with the conductivity meter and is expressed in (mg/L).
-
Turbidity Parameter
Turbidity is a measure of the clarity of the water. It is the amount of solids suspended in the water. It can be in the form of minerals or organic matter. It is a measure of the light scattering properties of water, thus an increase in the amount of suspended solid particles in the water may be visually described as cloudiness or muddiness. Turbidity is measured in Nephelometric Turbidity Units (NTU).
-
Streamflow/Discharge Parameter
The streamflow, or discharge, is the volume of water passing a single point in the stream over time. It is measured by determining the cross-sectional area and velocity (speed and direction) of the flowing water. The measurement is usually expressed in cubic feet per second (cfs).
-
Fecal Coliform Bacteria Parameter
Fecal coliform bacteria are microscopic organisms that live in the intestines of all warm blooded animals, and in animal wastes or feces eliminated from the intestinal tract. Fecal coliform bacteria may indicate the presence of disease carrying organisms which live in the same environment as the fecal coliform bacteria. The measurement is expressed as the number of organisms per 100 mL sample of water (#/100mL).
-
Analytical Procedures
All trained volunteers who will be involved in monitoring water quality and quantity parameters on the subject waterbody and its tributaries should follow specific procedures and protocols for the collecting and processing the data.
The volunteers should monitor all water quality and quantity parameters at all stations once every two weeks, or twice a month. All parameters should be sampled on the same day. The water quality parameters that should be monitored, field tested, and recorded on the data sheets include pH, temperature, dissolved oxygen, conductivity, and total dissolved solids (Data Sheet I, Appendix). All parameters should be tested on the same day with the potential exception of turbidity and fecal coliform samples. While the fecal coliform samples must be delivered to the lab, on the same day, the turbidity samples may be refrigerated at the office overnight, and may be tested the next day at the office. The biological oxygen demand results should be recorded after five days of testing.
-
Turbidity
Turbidity samples should be tested in the office, and results recorded on data sheets. The turbidity samples should be tested at the office at the end of the day, or within 30 hours from the time they were collected. If they are left overnight, they should be stored in a refrigerator at the office. If the turbidity samples are taken to a laboratory, they must be tested within 30 hours from the time they were collected in the field.
-
Fecal Coliform
Fecal coliform bacteria samples should be collected by the volunteers and brought to a certified laboratory. The fecal coliform samples need to arrive at the laboratory by the end of the sampling day unless other arrangements have been made. However, the fecal coliform samples will need to be tested within 30 hours from the time the first sample in the field was taken. All attempts should be made to get the samples to the lab on time. The lab should be called a day ahead of the actual sampling day, and also on the day of sampling, to remind the laboratory when samples will be brought to them to be tested.
-
Streamflow
Stream flow should be measured in the field and discharge results compiled in the office (Data Sheet II, Appendix). Data gathered should be compiled into a spreadsheet and analyzed by the project leader, the Washington Department of Ecolog. Stream flow measurements should be taken at specific locations at the same time the other water quality parameters are sampled. Stream flows should be measured at the following locations:
• Your monitoring stations should be identified here
Stream gages may be needed installed . The stream gages should provide the stream height of the water and can be used in concert with the stream discharge data.
Volunteers should work as a two-person crew while conducting all the necessary water quality monitoring in the field. The crew may decide to determine who is responsible for taking various measurements. For example, while one volunteer is obtaining the pH and temperature readings, the other volunteer may wish to conduct the conductivity and TDS sampling and testing. This may be beneficial due to time constraints in the field. However, streamflow measurements will require that both volunteers work together.
The day of the week that the sampling will occur may be decided by the project leader and the volunteer crew. Once a day is chosen, the sampling must be conducted on the same day of the week each time.
-
Certified Laboratory For Testing Fecal Coliform Samples
The Certified Laboratory you choose should agreed to process and test all fecal coliform samples that are collected for the the subject waterbody pilot water quality monitoring project.
The cost to process and test the fecal coliform bacteria samples is variable and should be negotiated. This should also includes testing turbidity if desired. The approved methods for testing each of these parameters is as follows:
Parameter Method Approval
Turbidity HACH PA 2000 Turbidimeter (Nephelometric Method) APHA 2130 B
Fecal Coliform Bacteria Membrane Filter Method APHA 9222 D

Sampling Procedures
The water quality parameters that should be sampled include pH, dissolved oxygen, biological oxygen demand (BOD), temperature, conductivity, total dissolved solids, turbidity, and fecal coliform bacteria. The water quantity parameter that should be sampled is the stream discharge, or streamflow. Each of these parameters should be sampled and tested directly in the field with the exception of turbidity and fecal coliform bacteria samples. While turbidity will be tested in the office, the fecal coliform bacteria samples should be taken directly to a certified laboratory for testing. The following sampling procedures should be followed by the trained volunteers conducting the water quality monitoring for each parameter:

pH Parameter
State Water Quality Standard for pH is within the range of 6.5 to 8.5.
Equipment Needed: pH meter, electrode (probe), buffer solutions for calibrating the instrument, distilled water, thermometer, and data sheet.
At The Office:
• Prepare the pH meter and probe for use.
• Calibrate the pH meter using the manufacturer's instructions. Complete the calibration and check the standard for this instrument. Record the calibration reading.
In The Field:
• At each station, turn the meter on and place the probe into the water column.
• Obtain the pH reading for each station. Wait until the meter reading stabilizes before reading and recording the pH and the temperature.
• Record the pH on the data sheet.
• A second sample should be taken in the field each sampling day, and the results recorded on the data sheet for pH. Do this before rinsing the probe.
• Rinse the probe with distilled water.
• Turn the pH meter off. Be careful to handle the probe carefully so as not to damage it while in the field. Recheck the standard again at the end of the day and record the reading. This should help determine the amount of "drift" from the first calibration taken in the morning.

Temperature Parameter
State Water Quality Standard for Temperature shall not exceed 18 degree Celsius
Equipment Needed- pH meter used for obtaining temperature, or thermometer, and data sheet.
In The Field:
• After taking the pH reading from the pH meter, obtain the temperature reading at each station and record it on the data sheet.
• Place the thermometer or pH meter in the water column.
• After the reading stabilizes, record it on the data sheet.
• A second sample should be taken in the field, and the results recorded for temperature on the data sheet.

Dissolved Oxygen (DO) Parameter
State Water Quality Standard for D.O. shall exceed 8.0 mg/L

Equipment Needed: Dissolved Oxygen meter, distilled water, and data sheet.
At The Office:

• Prepare the D.O. meter and probe for use.
• Calibrate the instrument according to the manufacturer's instructions.
• Record the calibration.
In The Field:
• At each station, turn the meter on and place the probe into the water column and stir with the probe.
• Allow sufficient time for the probe to stabilize before sampling the dissolved oxygen.
• Record the reading.
• A second sample should be taken in the field each sampling day, with results recorded for DO on the data sheets.
• Check the calibration of the instrument after each use and record the results.
• Rinse the probe with distilled water.
• Turn off the instrument and handle the probe carefully so as not to damage it while in the field.
• Recheck the standard of the instrument at the end of each sampling and record the reading.
• Recheck the standard at the end of the day and record the reading.
• A duplicate (replicate) sample should be taken in the field each sampling day and tested with results recorded for D.O. on data sheets. *Do this before rinsing the probe.

Biological Oxygen Demand (BOD) Parameter
No State Standard for BOD 5-day.

Equipment Needed: BOD Bottles, various reagents, 250mL graduated cylinder, 25mL buret, 2 droppers, and data sheet.
At The Office:
• The Winkler Method Buret Titration should be used to determine the 5-day BOD reading. For a complete description of this technique, consult the "HACH Water Analysis Handbook" (See Appendix).
In The Field:
• Collect a water sample in a clean 300mL., glass-stoppered BOD bottle. Add one Manganous Sulfate Powder Pillow and one Alkaline Iodide-Azide Reagent Powder Pillow to the bottle of water collected.
• Insert the stopper immediately into the bottle so that no air is trapped in the bottle. Invert several times to mix.
• Wait for the precipitate (floc) to form in the solution and settle. Again invert the bottle several times and wait until the floc has settled.
• Remove the stopper and add one Sulfamic Acid Powder Pillow. Replace the stopper without trapping air bubbles, and invert to mix several times.
• Pour the prepared sample into a 250mL graduated cylinder to the 200mL mark.
• Pour the contents of the graduated cylinder into a 250mL erlenmeyer flask.
• Fill a 25mL buret to the zero mark with PAO Titrant, 0.025 N.
• Titrate the prepared sample with PAO Titrant to a pale yellow color, and record the number of mL used.
• Add two droppers full of Starch Indicator Solution and swirl to mix.
• Continue the titration until the solution changes color from dark blue to colorless, and record the number of mL used.
• Calculate the BOD. (Use total mL Titrant Used = mg/L Dissolved Oxygen).
• Place the sample bottle in a refrigerator and incubate 5 days at 20 degrees Celsius.
• After 5 days remove the sample and place the dissolved oxygen probe into the bottle and record the results.

Conductivity Parameter
No State Water Quality Standards for Conductivity

Equipment Needed: Conductivity meter, distilled water, and data sheet.
At The Office:
• Prepare the conductivity meter and probe for use.
• Calibrate the conductivity meter according to the manufacturer's instructions and record the reading.
In The Field:
• Turn the conductivity meter on and place the probe into the water column and stir with the probe.
• Wait until the meter stabilizes to obtain the reading for conductivity. The meter should be in the "Conductivity Mode".
• Record the conductivity reading on the data sheet.
• Place the conductivity meter in the "TDS Mode" and obtain the "Total Dissolved Solids" reading while stirring with the probe.
• Record the TDS reading on the data sheet.
• A second sample should be taken in the field each sampling day and the results recorded for conductivity on the data sheets. Do this before rinsing the probe.
• Rinse the probe with distilled water.
• Recheck the standard of the instrument after each sampling, and record the reading. Also recheck the standard at the end of the day and record the reading.
• Turn off the conductivity meter and be careful when handling the meter and probe so as not to damage it while in the field.

Total Dissolved Solids
No State Water Quality Standard for TDS
Equipment Needed: Conductivity meter, distilled water, and data sheet.
At The Office:
• Perform all necessary calibrations for the conductivity meter since it will be used to obtain the total dissolved solids parameter.
In The Field:

• After the conductivity parameter has been measured and recorded, turn the conductivity meter to the "TDS Mode".
• Take the reading for TDS while stirring with the probe in the water column, and record the reading on the data sheet
• A second sample should be taken in the field each sampling day and the results recorded for TDS on the data sheet. Do this before rinsing the probe.
• Rinse the probe with distilled water.
• Follow the instructions for rechecking the conductivity meter standards after each sampling, and at the end of the day.

Turbidity Parameter
State Water Quality Standard For Turbidity is 5 NTU's

Equipment Needed- Turbidity Meter Kit, sterile tissues (kimwipes), distilled water, and data sheet.
In The Field:

• Use a clean, empty water quality bottle to collect the water sample. (Bottles can be pre-labeled with each station number to use in the field at each site.)
• Unscrew the cap. Be sure not to touch the inside of the bottle, nor the inside of the cap. It should remain as sterile as is possible.
• With the cap off the bottle, turn the bottle upside down and place the open end into the column of water. With the bottle upside down in the water column, turn the bottle to face upstream. Let the bottle fill with stream water.
• Bring the bottle back out of the water column and secure the cap.
• Mark the bottle (if it hasn't been pre-marked) with the station number that is being sampled. Keep this bottle as cool as is possible, and place it into an ice cooler when you reach your vehicle.
• Be sure to take a second sample each sampling day and test the sample in the office (or at the lab).
• Bring the sample back the office.
• While preparing the turbidity meter for use, let the turbidity sample bottles adjust to room temperature.
At The Office:

• NOTE: The following steps should be completed after returning from the field with the water sample.
• Prepare the turbidity meter for use.
• Calibrate the instrument according to the manufacturer's instructions and record the reading. Also, be sure to check the batteries for charge.
• Ensure that the water quality sample is well mixed by turning the sample bottle upside down 2-3 times. (Don't shake it!)
• Rinse a sterile and empty turbidity tube with some of the sampled water.
• Fill the turbidity tube to the neck with some of the sampled water.
• Cap the tube with a marked cap. (A single slash mark can be made on the top of the cap and then this mark is continually referenced in the same position as the tube is placed back into the turbidity meter each time).
• Wipe the tube with a lint-free tissue. Make sure there are no fingerprints, or other soil or oil particles on the tube. Place the clean tube into the chamber of the turbidity meter. Align the cap (with the slash mark) with the mark on the chamber.
• Select appropriate range on the selection knob.
• As soon as the reading stabilizes, record the reading as NTU on the data sheet.
• Remove the tube from the chamber. Empty and rinse the tube(s) with distilled water, dry tube(s), and store tubes in kit.
• Recheck the calibration of the turbidity meter when finished with all water quality samples, and record the reading.
• Test the duplicate (replicate) sample and record the results onto data sheet. Do this test after your last sample.

Fecal Coliform Bacteria Parameter
State Water Quality Standard For Fecal Coliform Bacteria is 100 organisms per 100mL.

Equipment Needed: Sterile water bottles supplied by certified laboratory, and data sheet.
At The Office:
• Pre-label the sterile bottles with each station number that will be used to collect the fecal coliform bacteria samples.
• Fill out a form per each bottle and rubber band the form to the bottle before you bring the samples to the lab to be tested.
In The Field
:
• Take the pre-labeled, sterile, fecal coliform collection bottle and wade into the stream. Take a sample in the middle of the stream.
• Carefully unscrew the cap from the bottle. Be sure not to touch the inside of the cap, nor the inside of the bottle at any time during the collection of the water sample.
• Turn the bottle upside down, with open end towards the water column.
• Submerge the bottle into the water column. Avoid collecting any water from the water surface.
• While bottle is submerged face it upstream in the water column.
• Once enough water has entered the bottle, shake a small portion out of the bottle so the water level is just below the neck of the bottle. This allows for some air exchange in the bottle.
• Carefully screw on the cap.
• Place the bottle into the ice cooler as soon as possible. (Samples should reach the lab. within 24 to 30 hours from the time the first sample is taken). At the end of the monitoring day, take all the fecal coliform samples to the lab. for processing and testing.
• Obtain more sterile bottles from the lab.
• If there is any reason to suspect that any bottle is unsterile, use a new bottle to obtain the sample.
• Be sure to take a duplicate sample once per month and have the lab test the sample. Be sure to label the bottle with a different number than those for each station. (For example, ST-12/A. This denotes the station number, and that "A" represents the duplicate you've taken). Record that a duplicate sample was taken on data sheets, and record results from lab results.

Stream Discharge/Flow Measurement
No State Standard for Discharge
Equipment Needed- Flow meter, measuring tape, clipboard, and data sheet.
In the Field:
• At each station, a flow measurement should be obtained.
• Follow the manufacturer's instructions and calibrate the flow meter.
• Determine where to take the flow measurement in the stream. Do not take the measurement in a pool. Take the measurement in a riffle or the tail out of a pool. The cross section of stream should be fairly uniform in depths across the section you will measure. There should be no major obstructions upstream or downstream of where the measurement is taken. Remove any movable obstructions from the stream such as debris, leaves, large rocks, sticks, etc. that would disrupt the flow or divert the flow of the stream. There should be enough water to submerge the flow meter as well. (If there is no available water at the station, for example, the water has gone subsurface, record this observation on the data sheets.)
• Spread the measuring tape out from left stream bank to right stream bank. The tape should be secured above the surface of the water on each bank and pulled taught. The tape should be within the wetted perimeter of the stream.
• Record the entire width distance from left to right bank on the data sheet. Leave the tape in place.
• Prepare the flow meter for use.
• Depending on the width of the stream, determine the increments across the width of the stream to obtain an accurate flow measurement. (Approximately 10 to 20 measurements may be necessary for accurate recordings of flows.) Increments should be equal distances apart. At each increment, record the tape value, or distance (width), depth, and velocity. To begin, read the measuring tape out to where the water starts from the bank and record the distance. If there is no water at this distance record "no flow" on data sheet. Take the first flow measurement at the edge of the bank where the bank meets the water, and record the flow data. (This will be your second width distance recording, but probably your first depth, and velocity measurement.) Record all flow measurements on data sheet.
• Proceed across the width of the stream recording the distance, depth, and velocity (as above) until you reach the other bank.
• When all flow data has been collected, reel up the measuring tape, secure all equipment, and travel to next station.
• The actual discharge factor will be derived at the office with the use of a calculator and discharge formula.

Water Quality and Water Quantity Parameters
The following table provides a listing of the water quality and water quantity parameters, the methods used to obtain the individual samples, and the reference of approvals by the specific entity.
FIELD PARAMETER METHOD REFERENCE*
pH Electrometric APHA 4500-H+
Temperature Electrometric APHA 4500-H+
Dissolved Oxygen Membrane Electrode APHA 4500-O G
Biological Oxygen Demand (BOD) 5-Day BOD Test APHA 5210 B
Conductivity Electrode APHA 2510 B
Turbidity Turbidimeter (Nephelometric) APHA 2130 B
Stream Flow Current Meter USGS 2175
Fecal Coliform Bacteria (Laboratory) Membrane Filter/Followed By Multiple Tube Fermentation Quality Control. APHA 9222 D/ APHA 9221

Water Quality Parameters
The following table represents the water quality parameters and the frequencies of calibrating the instruments, the check standards, field duplicates, and the measure of precision necessary to maintain and follow the quality control protocols for this water quality monitoring project plan.
PARAMETER CALIBRATION CHECK STANDARDS FIELD DUPLICATES PRECISION (RPD)**
pH daily twice daily 10% 10%
Temperature (C) daily twice daily 10% 10%
Dissolved Oxygen daily* twice daily 10% 10%
Conductivity daily twice daily 10% 10%
Turbidity daily twice daily 10% 20%
Fecal Coliform Laboratory Laboratory 10% 50%
* For D.O. the calibration should be checked at least twice daily (air calibration check), and results recorded. ** RPD, the Relative Percent Difference = difference x 100% mean

Field instrument specifications
PARAMETER INSTRUMENT RANGE ACCURACY
pH Hanna Waterproof pH Meter 0.00 to 14.00 +/- 0.01
Temperature Hanna Waterproof pH Meter 0.0 to 100 degrees C +/- 0.5 C
Dissolved Oxygen ORION Model 830 Waterproof Portable D.O. Meter 0.00 to 19.99 mg/L & 0.0-90.0 mg/L +/-5%, +/-1 digit, and 5 to 30 C
Biological Oxygen Demand (BOD) ORION Model 830 Waterproof Portable D.O. Meter 0.00 to 19.99 mg/L & 0.0-90.0 mg/L +/-5%, +/-1 digit, and 5 to 30 C
Conductivity ORION Model 130 Water proof Conductivity - TDS - Salinity - Temperature Meter Kit (Cond.) 0 to 199,990 in 6 ranges (Salinity) 0.0 to 70 .0ppt (TDS) 0 to 1999 mg/L (Cond.) 0.5% +/- 1 digit (Salinity) +/-0.1, 0.0 to 42.0 @ 5 Celsius (TDS) +/-2% +/- 1 digit, 15 to 35 C.
Total Dissolved Solids ORION Model 130 Waterproof Conductivity, TDS, Salinity, Temperature Meter Kit 0 to 1999 mg/L +/-2% +/- 1 digit, 15 to 35 C
Turbidity Meter Lamotte Digital Turbidity Meter 0 - 19.99 NTU 0 - 199.9 NTU +/-0.2% or +/-0.05 NTU
Flow (Discharge) Swoffer Model 2100-1514 Flow Meter 0.1-25 feet or 0.03-7.5 mps >1%
Fecal Coliform Bacteria Sterile Water Bottles determined by certified lab. certified lab.

» دراسة تقييمية لمياه الشرب فى مصر عموما وفى محافظة الشرقية خصوصا/SURVEY OF POTABLE WATER QUALITY PROBLEMS IN EGYPT GENERALY AND EL-SHARKIA GOV. ESPECIALLY
» كيفية تصميم وحدة فصل زيوت بناءا على تحاليل مياه الصرف/ Oil/Water Separator Decision - Flow Diagram
» كيفية اجراء العمليات الاحصائية المعملية
» 12-كتالوج اجهزة معمل تحاليل المياه والهندسة الصحية(عسر المياه)
» تحاليل المياه