EZ Series Online Analyzers

Biological contamination of water represents a major risk to plant, equipment and human health. Waterborne microorganisms represent a problem in many situations where water purity and hygiene are essential and where process optimization is crucial as well. Water utilities, oil & gas facilities, chemical manufacturers, data centers, bottling plants and power stations, therefore, measure microbial load to help minimize corrosion and optimize plant performance to alert you to possible bacterial outbreaks.

ATP in Industrial Applications

• Biofilm formation is a threat to the proper functioning of cooling water systems. Bacterial activity must be monitored and controlled by the use of biocides.

• Where biofilms can form, proper monitoring and treatment can reduce clogged or fouled filters, corrosion and lowered oxygen (leading to lowered pH) in the process stream.

• Reverse osmosis demineralization processes are also at risk of biofilm fouling, increasing operational and maintenance costs.

ATP in Municipal Applications

• Biofiltration monitoring

• Drinking water distribution

• Online microbiological monitoring is a useful and highly sensitive tool for demonstrating Log Removal Values of various unit processes used in direct and indirect potable reuse treatment.

• Recycled water/water reuse

Continuous Monitoring of Microbial Activity with EZ Series Online Analyzers

Traditionally, microbiological load or contamination was measured manually in a lab setting. But now, with the Hach EZ7300 online ATP analyzer, microbiological activity can be measured continuously within the process stream, delivering data that allows operators to intervene as soon as a change in the activity is observed.

The EZ7300 determines total bacterial content by measuring ATP of any type of microorganism present in the water sample. And by quantifying intracellular, extracellular and total ATP in the sample, operators can now differentiate ATP in a living cell versus ATP released from a cell that has been subject to disinfection or lysis.

The EZ7300 series can also be used to measure the effectiveness of the biocides being used in the treatment process, to optimize the dosing regime and help avoid damage to health, environment and infrastructure.

Applications:

- Cooling Water
- Drinking Water
- Process Water

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Effective monitoring and treatment of hardness and alkalinity are key to maintaining stable water in a variety of processes. Hardness and alkalinity are used along with pH, TDS/conductivity and temperature, in the calculation of the Langelier Saturation Index (LSI) to measure water’s propensity to either corrode metals or deposit a scale in a pipe. With the data from continuously monitoring these parameters, plant operators can adjust a process to ensure compliance, avoid permit violations, maximize efficiency, control costs and operate at the highest levels of health and safety.

Alkalinity in Wastewater

• Alkalinity is a key parameter to ensure proper biological and chemical functions in wastewater. Nitrifying bacteria are highly susceptible to changing wastewater characteristics with alkalinity being a well understood measurement that must be monitored. Alkalinity is consumed during the nitrification process and as the water becomes more acidic the pH drops. If pH levels drop below 7, nitrification rates will begin to degrade. If the pH continues to decline nitrification could be inhibited causing high levels of ammonia in the effluent.

• Microorganisms such as polyphosphate accumulating organisms (PAOs) favor environments with higher alkalinity and an optimal pH around 8. Decreasing alkalinity levels can lead to a lower phosphate uptake rate, resulting in higher levels of phosphorus leaving the secondary treatment processes.

• Buffering chemicals dosed either in biological reactors or after secondary treatment can be effectively controlled with online alkalinity monitoring to maintain optimal biological conditions and effluent pH permit requirements. Alkalinity measurements in wastewater will start to respond before pH changes occur, providing additional time for proactive operational controls to be implemented.

• Insufficient alkalinity can impact downstream process that are pH sensitive. For example, chemical phosphorus removal processes and gas chlorine disinfection can consume alkalinity and compromise effluent pH violations.

Alkalinity in Industrial Applications (Power, Boiler and Steam)

• In industrial applications (power generation, boiler and steam processes) monitoring alkalinity is crucial. Whether in the raw intake water, treated boiler water or post-boiler steam condensate water being routed back for reuse, proper monitoring and management of alkalinity helps to ensure safe and efficient operations, reducing potential maintenance and protecting infrastructure. In boiler water, alkalinity levels should be kept above 200ppm to prevent acidic corrosion but should not exceed approx. 700ppm to avoid excessive foaming and scale formation in pipes, pumps, boilers or other equipment.

• For DBPR compliance, alkalinity is a core parameter that relates to how much Total Organic Carbon (TOC) needs to be removed from source water to limit DBPR formation. In blended waters where alkalinity (and TOC) can vary, online measurements will immediately inform the utility about any changes that may affect DBPR.

• Corrosion control in distribution systems is top of mind for many utilities. Alkalinity is a key parameter that relates to the buffering capacity of water, which indicates how likely a pH drop is to occur. Since a drop in pH increases the probability of lead and copper entering the drinking water supply, an online alkalinity measurement will provide real-time data about corrosion parameters related to common calculations like LSI.

• Systems that use monochloramine as measurable residual in their distribution network also track alkalinity. A consumption of alkalinity can be a leading indicator of nitrification in the distribution system, which can lead to a variety of other water quality challenges.

Applications:

- Drinking Water
- Industrial
- Power, Boiler and Steam
- Surface Water
- Wastewater

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Fluoride is found naturally in soil, water and foods. It is also produced synthetically for use in drinking water, toothpaste, mouthwashes and various chemical products. Naturally occurring fluoride exists in all oceans, surface water and groundwater sources, at concentrations from 0.1 to 13 mg/L.

Fluoride in Drinking Water

• When maintained and dosed at the determined appropriate level, the occurrence of fluoride in drinking water has positive effects. Studies have shown that adding it in areas where fluoride levels in the water are extremely low can reduce the prevalence of tooth decay in the local population through demineralization and remineralization. For example in the United States, fluoride is often added to drinking water but concentration may not exceed 4 mg/L in public water supplies and most utilities keep this concentration below 1 mg/L. In Europe and other parts of the world, the addition of fluoride to drinking water is not common.

Fluoride in Industry and Wastewater

• Fluoride can be commonly discharged as effluent in many chemical industries and be a challenge for industries using hydrofluoric acid (HF) as a cleaning agent or etchant, such as the semiconductor, solar cell and metals manufacturing industries. When fluoride concentrations are too high in biological wastewater treatment systems, it can be toxic to bacterial colonies. Studies indicate that anaerobic microorganisms involved in various metabolic steps of treatment or anaerobic digestion processes are very sensitive to the presence of fluoride; in addition, fluoride can inhibit the nitrification process. An excess of fluoride in effluent discharge may represent a health hazard, so treatment is necessary to reduce concentrations to an acceptable level.

Applications:

- Drinking Water

- Chemical Processing

- Industrial Applications

- Process Water

- Surface Water

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Iron is a naturally occurring mineral in both groundwater and surface water, often viewed as a water quality indicator during and after the treatment process. In some process applications, iron can also act as a control. So accurate, continuous monitoring of this trace metal is crucial to maintaining quality of both plant processes and output. Whatever the source, concentrations of iron that exceed acceptable levels must be identified and removed.

Iron in Drinking Water

• While it does not pose an acute health risk, elevated iron concentrations are undesirable in drinking water due to aesthetics such as taste and appearance. Iron in source water is frequently removed using a pre-oxidation step to allow iron to be converted to an insoluble form that can be settled out during sedimentation. Oxidant (such as ozone, chlorine dioxide, permanganate and chlorine) dosing can be efficiently controlled with an online free or total iron measurement. Permanganate dosing can be monitored to prevent overdosing and making pink water. A dual stream online analysis can also show before and after values to demonstrate how much iron is (or isn’t) removed.

Iron in Wastewater

• Metal salts such as ferric chloride are used in phosphorus removal systems and can be dosed at various locations in the treatment process. While orthophosphate (PO4) is the typical measurement used to monitor chemical phosphorus removal efficiency and to control dosing, a facility may also be interested in measuring residual iron to protect downstream processes, such as scale prevention in UV disinfection equipment.

Continuous Monitoring of Iron with EZ Series Online Analyzers

The measurement of iron by colorimetry is represented by the Hach EZ1000 and EZ2000 series models in a variety of measurement ranges. The EZ Series analyzers are capable of measuring total or dissolved concentrations and have optional multi-stream capability, as well a grab sample port for introducing grab sample into the instrument.

EZ Series online analyzers can monitor various points within the deferrization process and can be used to monitor and confirm initial lab results in iron concentrations before the actual treatment process. After the removal process, measurements can confirm that any remaining traces of the parameters exist in concentrations that meet permit requirements.

EZ series offers automatic and trouble-free measurement of iron at several stages of the process, offering an elegant solution to iron measurement and treatment.

Applications:

- Drinking Water
- Power and Steam Generation
- Surface Water
- Wastewater

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