Introduction
Safe drinking water is essential to good health, but conventional methods of water quality testing have depended on sophisticated laboratories and highly trained technicians largely unavailable in developing countries and remote communities in Canada. Without adequate water testing, people may unknowingly drink contaminated water containing viruses and bacteria linked to potentially fatal diseases such as cholera, typhoid fever, dysentery, and infectious hepatitis.
For a correct implementation of production processes companies have to perform water analyses of representative water samples regularly.
What needs to be analyzed?
A number of parameters can be determined on site with conventional
meters. Examples of such parameters are the acidity (pH), conductivity,
temperature (degrees Celsius), redox potential, oxygen concentrations and
flow (m3/h). However, selective measurements of specific ions,
minerals and salts cannot be performed on site. To be able to measure these
parameters, samples should be taken to the laboratory, to be analyzed. For
parameters that need to be determined during wastewater treatment, such as BOD (biochemical oxygen demand), COD (chemical oxygen demand), Nkj (Kjeldahl
nitrogen), suspended solids, or heavy metals, samples also need to be
analyzed. For microbial processes that can cause contamination the number of
colony forming units (CFU) has to be determined. Periodically one has to
measure and register the microbial activity. Fungi, bacteria and viruses
have to be measured separately, only the total number CFU does not suffice.
An example of such a determination is the legionella analyses.
Examples of branches and water processes that often require water
analyses
- Wastewater - to determine and verification the deposition value and
deposition levies and to control the deposition of dangerous substances.
- Boiler Feedwater - determination of the clarity, oxygen concentrations
and silica concentrations of the feed water.
- Agricultural Feedwater - determination of nutrients and microbial
activity. Reuse and affectivity control of ozonators and uv disinfection
units. Determination of the ion balances.
- Cooling water - determination of hardness, to be able to determine
whether scaling prevention needs to be applied. Legionella determination.
- Bottled water - determination of the composition of minerals and the
number of CFU after bottling of the water that has been treated with ozone.
- Swimming pool water - determination of free, bound and dosed chlorine
and chloramines and the affectivity of the applied uv-disinfection units and
ozonators.
Results and presentation of water analyses
The report we will supply can consist of a single parameter of the
sample that has been analyzed, such as the presence of certain bacteria. It
can also consist of a full reproduction in tables of all ions in ppm or ppb.
We can also provide you with conclusions and recommendations
considering the precautions you need to take when the results of the
analyses are known, to be able to reach a proper water quality.
There is a big difference between soil chemistry and water chemistry: compounds present in soil are often there in large quantities per unit volume, while in water, small quantities are usually the rule.
However, these small concentrations--usually measured in parts per million or parts per billion--will determine how the water needs to be treated. For example, a concentration of 50 parts per billion of phosphorus can cause algal blooms in a dugout. A concentration of 1.5 parts per billion of the cyano bacterial (blue-green algal) toxin microcystin LR exceeds Canadian drinking water guidelines.
So, small amounts can make a big difference in how we deal with a water source. To get accurate levels of these compounds it's essential that not only one, but several steps, are carried out with the utmost care and knowledge.
Step 1: Prepare sample containers for sampling. These containers mustn't contain any of the compounds that samples are to be analyzed for. Sampling bottle material must be suitable for sampling the water without affecting the compound.
Step 2: The sampling procedure. This must be rigorous, ensuring that a representative sample is collected and at no time is the sample or sample bottle contaminated by the collector. This is no trivial task when it comes to collecting samples with low levels of compounds such as phosphorus. Depending on the compounds to be analyzed, a preservative may be necessary.
Step 3: Transport to the laboratory for analysis. This needs to be done under appropriate conditions, often in a dark cooler with ice packs.
Step 4: Processing the water sample. Many samples need to be filtered before testing. In some cases, the filtering step must be done in the field as soon as the sample has been collected. The sample analysis needs to be carried out according to a protocol that doesn't introduce contaminants or otherwise compromise the sample. After suitable processing, the sample is ready to be analyzed.
Step 5: Analysis. This fifth step can also introduce problems. The laboratory needs to have quality control/assurance procedures in place so analytical values aren't compromised.