As part of the management and monitoring of wastewater treatment systems, sample collection for laboratory analysis is of critical importance. At DBO International, we have developed advanced wastewater treatment solutions, enabling the application of optimized sampling procedures to ensure the quality and compliance of treated effluents. This InfoDBO presents the sample collection method for our systems, ensuring rigorous performance monitoring.
Best practices for water sampling
To ensure reliable and representative analysis results, it is essential to follow these best practices during water sampling:
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- Use Clean and Sterile Equipment: All sampling equipment (containers, pumps, sieves, etc.) must be clean and sterile to prevent cross-contamination of samples.
- Wear Personal Protective Equipment (PPE): Gloves, safety glasses, and other protective gear must be worn during sampling to protect both the sample and the operator.
- Sample Under Representative Conditions: Select sampling points that reflect the actual conditions of the system, avoiding stagnant areas or those with low flow that could skew results.
- Rinse Sampling Containers: Before collecting a sample, rinse containers with a small amount of the water being sampled to avoid residues from previous samples or preservatives.
- Observe Proper Storage Conditions: Place samples in containers provided by the laboratory and immediately store them in a cooler or refrigerator to maintain an optimal temperature (typically between 0 and 4°C) until delivery to the laboratory.
- Minimize Excessive Aeration: Avoid excessive agitation or aeration of samples, as it could alter certain parameters, such as dissolved gases (e.g., oxygen or CO2), and distort analysis results.
- Document Every Step: Carefully record the date, time, and conditions of the sampling, as well as any unusual events that could affect sample quality. This includes information such as the time elapsed between sampling and delivery to the laboratory.
- Meet Analysis Deadlines: Deliver samples to the laboratory as soon as possible to ensure valid results, respecting the specified preservation times for each type of analysis (e.g., some bacteriological analyses must be performed within 24 hours of sampling).
- Clearly Label Samples: Each container must be labeled with precise information such as the sampling site, collection date and time, and the operator’s name, ensuring traceability and the integrity of analytical data.
Required equipment
To facilitate the sampling of effluent from DBOI systems using the sampling device, the following items are required:
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- Sampler equipped with a peristaltic pump to ensure controlled, contamination-free collection.
- Flashlight to visually inspect dark areas of the device.
- Cooler and laboratory-provided containers to store the samples properly.
- A container with a 100 mm diameter and 125 mm height, mounted on a pole at the required height so that the top of the container sits just below the inlet pipe of the sensor.
- A 0.25 mm sieve to filter the collected samples.
Sampling procedure
Method with Peristaltic Pump
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- Remove the plastic seal from the sampling device’s cover.
- Remove the cover from the sampling device.
Note : If water is present in the well above the infiltration pipe, this may indicate that the sand is 100% saturated or the groundwater level is higher than the receiving soil. In these cases, it is recommended to restore the hydraulic balance before sampling. - Insert the strainer connected to the peristaltic pump into the bottom of the container to collect the water.
- Place the container under the sampling device so that any new water flows into it, with excess water draining to the bottom of the well.
- Program the sampler to collect the amount of water needed for analysis.
- Protect the sampler from weather during the collection process.
- Filter the collected water using the 0.25 mm sieve to remove large particles.
- Pour the filtrate into laboratory-provided containers.
- Place the sample containers in a cooler to keep them cool.
- Discharge any remaining water into the piezometer connected to one of the pipe rows.
- Replace the cover of the sampling device and reattach the plastic seal.
- Record the date and time of the sampling.
- Deliver the samples promptly to the laboratory.
- Restore the site to its original condition.
Alternative Method Without Peristaltic Pump
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- Remove the plastic seal from the sampling device’s cover.
- Remove the cover from the sampling device.
Note : If water is present in the well above the infiltration pipe, check whether the soil is saturated or if the groundwater level is too high before proceeding. - Use a sterile bottle attached to a pole to manually collect the sample by lowering it to the bottom of the well. Ensure the container is correctly positioned under the sampling device to capture the water as it flows.
- Collect water in the container until the required amount for analysis is reached, then pour the contents into laboratory-provided containers.
- Filter the water using the 0.25 mm sieve if necessary.
- Place the sample containers in a cooler to keep them cool.
- Discharge any remaining water into the piezometer connected to one of the pipe rows.
- Replace the cover of the sampling device and reattach the plastic seal.
- Record the date and time of the sampling.
- Deliver the samples promptly to the laboratory.
- Restore the site to its original condition.
Visual and olfactory techniques for effluent evaluation
Effluent evaluation is performed by observing its appearance and odor:
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- Visual Evaluation: Place the sample in a transparent container and observe it against a white surface (e.g., a sheet of paper). If the effluent is dark in color or shows high turbidity, this may indicate a malfunction in the treatment system.
- Olfactory Evaluation: Gently swirl the liquid in the container. If an ammonia-like (sharp) smell, hydrogen sulfide (rotten egg) odor, or any otherstrong odor is detected, it also suggests a system failure.
If there are signs of malfunction, a detailed analysis (BOD5, suspended solids, fecal coliforms) should be conducted.
Effluent assessment – TSS, BOD5, and fecal coliforms
Collected samples must be placed in appropriate containers and sent to an accredited laboratory following approved preservation methods. Once the laboratory completes the analyses, the results should be forwarded to the DBO International (DBOI) technical team for in-depth review. The team will assess the data to ensure that the effluent complies with current quality standards and will verify the ongoing performance of the wastewater treatment system.
Conclusion
Rigorous sampling and effluent evaluation are essential to ensure the performance and compliance of wastewater treatment systems. By following the methods and best practices outlined, DBO International ensures accurate and reliable monitoring of treated water quality. Every step, from sample collection to storage, contributes to data traceability and the integrity of analysis results.
Through these optimized procedures, we strengthen trust in our systems and ensure compliance with the strictest environmental standards. DBOI’s commitment to proactive management not only enables the rapid detection of anomalies but also ensures the long-term sustainability of the implemented solutions.
Here’s the infoDBO : Sample Collection and Evaluation Method