How to select water purity monitors for 24/7 reassurance.

The leading providers of continuous water quality monitoring instrumentation frequently claim similar levels of performance, so it can be challenging to choose the best measurement technology with which to entrust critical manufacturing processes. In this article, Russell Culver from Swan Analytical explains why some of the key differentiators are not shown in specification sheets.

Russell Culver,  Swan Analytical

Background.
Continuous monitoring equipment plays an essential role in most manufacturing processes, protecting product quality, lowering costs, avoiding waste and ensuring regulatory compliance. For the purposes of this article, we will study the monitoring of total organic carbon (TOC) in purified water systems.

The quality of purified water is particularly important for most manufacturers, but especially so for the manufacturers of pharmaceuticals, medicines and personal care products. Cutting-edge measurement technology is therefore essential to ensure the quality and reliability of purified water systems.

TOC is a particularly important measurement in pure water systems because it provides a failsafe method to immediately detect any unwanted organic content. Contamination may result from sources present in the supply water and not removed by the purification process. However, contamination may also arise from within the high purity water system itself. Sources include piping, filters, valves, biofilm buildup, system leaks, adhesives, process gases, ion-exchange resins and thermoplastic breakdown products created during sterilisation procedures. Continuous monitoring, a fast response time and reliability are therefore essential – to monitor trends and raise alarms.

The Pharmacopeia regulations.
TOC is one of the four critical parameters defined by the Pharmacopeia to ensure the quality of purified water (PW) and water for injection (WFI).

The objectives of the United States Pharmacopeia standard USP <643> are to ensure the accurate measurement of TOC and to provide guidance on how to achieve that goal. USP <643> does not specify a particular analytical method, however it does specify the criteria for qualifying TOC instrumentation and for the interpretation of results. For example, instruments should be able to distinguish between organic and inorganic carbon, and must have a detection limit specified by the manufacturer of 0.05 mg/L (equivalent to 0.05 ppm or 50 ppb). Also, instruments must be calibrated according to the manufacturer’s instructions and regularly subjected to a System Suitability Test (SST). USP <643> intentionally says nothing about how often the SST should be run, because the frequency depends on the stability of the TOC instrument response and other factors associated with water quality and risk.

USP <643> states that TOC must not exceed the defined limit, which is the response of the TOC analyzer to a 500ppbC standard made from USP-traceable sucrose. This means that the value which a specific TOC analyser gives for USP-traceable 500ppbC sucrose becomes the limit value.

Continuous TOC monitoring is also specified in European standards. For example, the EU GMP Annexe 1 requires water for injection systems to include continuous monitoring systems such as TOC and conductivity, (unless justified otherwise) as these may give a better indication of overall system performance than discrete sampling. Sensor locations should be based on risk and the outcome of qualification.

Spec sheet conundrum.
One of the key challenges facing process managers is how to choose instrumentation when all the spec sheets look the same! This is because measurement instrumentation frequently employs the same or similar detection technology, so performance measures such as accuracy and resolution are inevitably similar. The key differences between different manufacturers therefore mainly relate to issues such as measurement stability, reliability, and ease of use. However, these characteristics are difficult to define on specification sheets, but feature prominently in the minds of existing users.

Case study - pharmaceutical manufacturer.

One of Swan Analytical’s customers is a well-known global brand in the body care and fragrance sectors with a British manufacturing facility using purified hot and cold water for both manufacturing and cleaning purposes. The level of purification is critical for the quality of their products, so a comprehensive continuous water quality monitoring network has been established for quality control and regulatory compliance.

The company takes an uncompromising approach to quality, covering every stage of the development and manufacture of its products, with rigorous compliance to some of the strictest regulations in the world. In addition, the company’s state-of-the-art manufacturing facilities feature the most advanced testing equipment to guarantee product quality. All manufacturing equipment is tested and certified, and every production process is validated.

Local engineering staff have commented that most reputable instruments can be relied on to deliver accurate results, but they believe that the key differentiators are the ease and cost of maintenance procedures such as service and calibration. These are not issues that can generally be assessed in product literature, so it is necessary to learn from the experience of existing users. However, in this example, the user already had the prior benefit of an existing Swan chlorine analyser which was employed to continually check the performance of a carbon filtration system. This provided the level of confidence necessary to subsequently deploy a Swan analyser for the measurement of TOC. Importantly, the client chose Swan, not because it was more accurate than its predecessor, but because it was so much easier to manage.

Swan analysers are simpler to maintain because they have a modular design. This means that the footprint is very slightly larger, but importantly, service and calibration work is improved, because it is easier and less costly to work on or replace individual modules. In addition, the Swan analysers come with a 3-year warranty, which is quite unusual in this market.

To further extend confidence and reliability in continuous monitoring systems, many UK customers are covered by a service contract under which Swan engineers conduct a preventative maintenance and SST/calibration check every 6 months. The resulting service report and calibration certificate can form part of an internal audit procedure, as well as external audits by organisations such as the US Food & Drug Administration (FDA).

Summary.
The accuracy and performance of Swan’s AMI LineTOC analysers are equivalent to other leading manufacturers, but for many users a key point of differentiation is the ease of maintenance. This generally results in lower operational costs, but in comparison with other continuous monitors, Swan instruments also represent a lower capital cost.

In addition to online monitoring, many customers take water samples from multiple locations for laboratory analysis. This enables the measurement of a wide variety of parameters, but lacks the advantages of continuous monitoring. For example, online instruments provide 24/7 reassurance that processes are in perfect condition and fully compliant with pharmacopoeia and all applicable regulations. These continuous measurements are extremely important, not just for regulatory compliance, but also to provide fast alerts to prevent any possibility of product contamination.

In conclusion, most instrument manufacturers publish high levels of performance for their monitors, so it can be difficult to choose one over another. It is therefore important to seek the views of existing users, most of whom will emphasise the importance of maintenance ease and cost.

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@_Enviro_News @swan_usa #Pharma #Water

TOC monitor.

A new generation of TOC monitors for regulatory compliance in pure, ultrapure and WFI water applications has been announced by Swan Analytical. With simple, intuitive controls and rugged components, the new AMI-II LineTOC analysers enhance reliability in the continuous measurement of total organic carbon (TOC).

“The AMI-II LineTOC instruments have been developed to meet a number of important customer needs,” explained Swan’s Russell Culver (Pharma Business Development Manager*). “First and foremost, the monitor enables Pharmacopoeia compliance whilst supporting FDA 21 CFR Part 11, providing a compliant audit trail. However, the instrument is simple to operate, requiring minimal training, even for validation and calibration. Combine this with long-term reliability, durability and the AMI-II LineTOC lowers not just the cost of purchase, but also the cost of ownership.”

TOC derived from organics is one of the most common sources of contamination in ultra-pure water systems, so monitoring is mandatory in the pharmaceutical industry, where UPW is used as a process medium, as a solvent, as an ingredient, as medical water for injection, and within APIs, intermediates and reagents. Continuous monitoring and a fast reliable response time are therefore essential – to detect any contamination, to monitor trends and raise alarms of excursions.

The new AMI-II LineTOC provides reagent-free TOC measurement by conductivity differential before and after UV-oxidation. With a new enhanced display/transmitter the analyser offers a wide measurement range from 0 to 1000 ppb with a resolution of 0.01 ppb in its lowest range. A compact version of the AMI-II LineTOC is also available to facilitate greater flexibility where space is of a premium, making it suitable for integration in water purification systems or distribution skids.

Both versions of the AMI-II LineTOC are supplied as a complete working system, which means that it is not necessary to purchase secondary equipment, such as a calibration module for example. Standard equipment includes three sample bottles that can be utilised during functionality and system suitability tests, or as the repository for grab samples – thereby avoiding the need for laboratory analysis.

Looking forward, Russell says: “We are tremendously excited about the opportunities that exist for this new generation of monitors in a variety of sectors where the continuous monitoring of pure and ultrapure water is either essential or mandatory, or both. For example, with IQ/OQ/PQ validation and full compliance to Global Pharmacopoeias and FDA 21 CFR Part 11, the new AMI-II LineTOC will bring peace of mind to pharmaceutical manufacturers and system providers alike.”

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* Pharma business development Manager. (21/1/2025)

@_Enviro_News @swan_usa #PAuto #Water

Pure & ultrapure water analysis.

A new compact version of its Swan Analytical's AMI LineTOC monitor for pure and ultrapure water applications has been launched.

“This new instrument is simple to install and run; fully compliant with industry standards, and suitable for the continuous monitoring of medical water for injection and pure water in pharmaceutical and related industries, as well as ultrapure water in the semiconductor industry,” explains Sales Manager for Britain, John Saxton. “The new compact version retains a user-friendly design which allows easy access to system components, in a format that lends itself to installations in common mounting spaces on water purification or distribution skids.”

The AMI LineTOC Compact Version provides reagent-free measurement of total organic carbon (TOC) by UV oxidation and differential conductivity detection. With a fast response time of under two minutes, the device offers a wide measurement range from 0 to 1000 ppb with a resolution of 0.01 ppb in its lowest range.

Organic contaminants in pure and ultrapure water represent a significant threat to product quality and process efficiency in a wide variety of industries. If undetected, organic contaminants can also encourage the growth of microorganisms. In the semiconductor industry, organic contamination causes defects in sensitive photolithographic processes which damage wafers and reduce yield. In the pharmaceutical industry, the effects of organic contamination can range from troublesome to potentially lethal defects.

TOC derived from organics is frequently the largest source of contamination in UPW systems. Contamination may result from sources present in the supply water and not removed by the purification process. However, contamination may also arise from within the high purity water system itself. Sources include piping, filters, adhesives, process gases, ion-exchange resins and thermoplastic breakdown products created during sterilisation procedures. Continuous monitoring and a fast response time are therefore essential – to monitor trends and raise alarms.

Compliance is assured by the AMI LineTOC Compact with a fully integrated and automatic system suitability test (SST) according to USP <643> and Ph. Eur 2.2.44. An optional validation package is also available for hassle-free instrument qualification during commissioning. In addition, the instrument’s firmware provides access protection and an audit trail with event logging.

Summarising John says: “Working closely with customers, we developed the AMI LineTOC Compact Version to meet their specific needs. For example, an on-board pump stabilises flow and minimises the potential for sample contamination, so that the instrument is not reliant on sample flow rate. In addition, with a built-in cooler, hot samples can be handled with ease.

“Other small but important features include simple access to grab samples, and an optional removeable stainless-steel cover. However, the most important deliverables from the AMI LineTOC Compact Version are reliable regulatory compliance from an instrument that is simple to install, operate, calibrate, and maintain, which means that users can protect water quality and minimise operational costs.”

@_Enviro_News @swan_usa #PAuto #Water

Analysers for monitoring low-TOC values.

Total organic carbon (TOC) is an important quality parameter in the various manufacturing and process environments that depend on ultrapure water. When TOC content is too high, it can adversely impact the performance of water treatment systems, compromise high-precision machinery, or contaminate batches. The CA78 and CA79 online TOC analyzers from Endress+Hauser provide continuous and precise monitoring to ensure stable operations, regulatory compliance, and high-quality products.

Real-time water quality assessment for minimal product contamination.

These TOC analyzers utilize proven UV-oxidation and differential conductivity measurement, the most-established method for reliable TOC trace analysis in ultrapure water. The fast response time (t90) of 50 seconds enables quick control system and personnel reaction in the event of water quality deterioration, reducing contamination, product loss, and costs. Complete measuring point management.
The analyzers’ user-friendly modular design and easy accessibility to components simplify maintenance and minimize operating costs. Additionally, Endress+Hauser’s worldwide service network provides end users with complete measuring point management throughout plant lifecycles, including installation qualification and operational qualification.

CA78 in the power & energy, semiconductor, personal care product, and disinfectant manufacturing sectors.
The CA78 TOC analyzer supports safe operations in many applications, including but not limited to:

• Protecting turbines and other expensive power plant equipment. • Manufacturing semiconductors and additional microelectronics. • Ensuring product quality in the personal care industry. • Assuring the efficacy of disinfectants.

The CA78 is configurable to meet various requirements in the power and semiconductor industries. For example, the standard version is the right choice for measuring ultrapure water in semiconductor production, providing high-precision measurement in water with conductivity values up to 2 µS/cm. Meanwhile, the instrument option for measurement in water with conductivity values closer to 10 µS/cm is perfectly-suited for deionized water in power plants. When multiple TOC measuring points are required, the 3-channel configuration allows for multiple streams to be run through one analyzer, which reduces capital expenditures.

Pharma-compliant CA79.
The CA79 TOC analyzer meets or exceeds all requirements of the US and European Pharmacopoeias, enabling manufacturing activities in accordance with FDA 21 CFR Part 11. Depending on the instrument configuration, online calibration and system suitability tests (SSTs) can be initiated with the press of a button, and these records are automatically stored onboard.

Regular SSTs ensure compliance with the pharmacopoeias’ regulations for TOC values. And with a compact, stainless-steel housing, the CA79 integrates seamlessly into ultrapure water installations, ideally situating it for use in applications subject to the stringent hygiene requirements of the life sciences industry. 

Complete portfolio for multiple industries.
With the introduction of the CA78 and CA79 analyzers for low-TOC measurement ranges, Endress+Hauser is rounding out its liquid analysis solutions for critical parameter measurement.

The CA78 supplements Memosens CLS15E contacting conductivity sensors, Liquiline System CA80SI silica analyzers, CA76NA sodium analyzers, and SWAS panels for reliable, low-maintenance solutions in a variety of sectors. The CA79 complements the Memosens CPS61E pH sensor, Memosens COS81E oxygen sensor, and Memosens CLS82E conductivity sensor for critical parameter measurement in pharmaceutical production environments.

These analyzers each store critical process, calibration, and sensor data locally, with transmission to a central process control and documentation hub, which is especially important in highly-regulated industries. This plethora of high-precision instruments provides end users with a complete portfolio of sensors, photometers, and TOC analyzers, and now all of these measurements can be monitored and managed at a single source.

@Endress_US @Endress_Hauser @Endress_UK #PAuto

TOC analysers Distributership announced.

ErsaTec GmbH, the manufacturer of gas analysers for the measurement of organic gases (TOC) such as solvents and fuels, has appointed Quantitech as exclusive distributor of their products in Ireland and Britain.

Designed and developed by former employees of Bernath Atomic (manufacturer of the well-known Bernath 3006 FID), the ErsaTec analysers employ Flame Ionisation Detectors (FIDs) to measure total organic carbon. The product range includes both continuous and semi-continuous analysers for use in a wide variety of industrial applications.

“We are delighted to be given this opportunity,” says Sales Director Dominic Duggan. “Quantitech has been selling FID instruments for around 20 years and we are very excited to be able to offer a choice of fixed and transportable versions.

“The ErsaTec products are ideal for Part B Processes and Test Houses; offering advanced FID technology at highly competitive prices. The range offers a number of very attractive advantages; for example, the SmartFID instruments have internal dataloggers and are very easy to set up and run with an intuitive touchscreen.”

FID analysers require a fuel source and with dual range capability (low range to 10ppm and high range to 100,000ppm) the ErsaTec FIDs can operate on either hydrogen or a hydrogen/helium mix. However, hydrogen consumption is very low and this is the most economical choice.

• Under the Environmental Permitting (England and Wales) Regulations 2010, local authorities must regulate certain types of factory. This is to reduce any pollution they may cause and, in particular, to help improve air quality. Businesses which operate these premises must seek a permit and in doing so, will need to demonstrate compliance with emission limits, so for most of these (over 17,000) processes monitoring will be necessary, and for many of them that will include the measurement of organic gases such as solvents.
The British Department for Environment Food & Rural Affairs (Defra) has published Process Guidance Notes for a wide range of affected processes.

@Quantitech #ERsaTech #PAuto #Britain #Ireland

TOC analysers for Britain & Ireland.

Quantitech has been appointed exclusive distributor in Britain and Ireland for ErsaTec  gas analysers for the measurement of organic gases such as solvents and fuels.

Designed and developed by former employees of Bernath Atomic (manufacturer of the well-known Bernath 3006 FID), the ErsaTec analysers employ Flame Ionisation Detectors (FIDs) to measure total organic carbon. The product range includes both continuous and semi-continuous analysers for use in a wide variety of industrial applications.

The ErsaTec SmartFID instruments have internal dataloggers and are very easy to set up and run with an intuitive touchscreen. The instruments have both a low range to 10ppm and a high range to 100,000ppm, and with very low fuel consumption they offer low capital and operational costs.

Sensors for TOC monitoring!

Sensors from Edinburgh Sensors, are now being integrated into a number of systems for Total Organic Carbon (TOC) measurement. A number of key global players have adopted Edinburgh Sensors products into their applications and as interest continues, Edinburgh Sensors are becoming the product of choice.

Total Organic Carbon represents a measure of the amount of carbon, in a water sample, that has a biological source, this includes oil.

The Total Inorganic Carbon (TIC) is typically removed from a sample using acidification and/or purging before oxidising the remaining organic carbon in the water sample to carbon dioxide and then measuring the amount of carbon dioxide produced.

There are several methods of oxidising the organic carbon employing: - oxygen, wet chemistry, UV radiation or heat to produce the carbon dioxide. Whichever method is used, the result is carbon dioxide dissolved in a carrier gas, commonly oxygen.

The carrier gas is passed through the Edinburgh Sensors NDIR gas sensor to measure the carbon dioxide content. The higher the carbon dioxide concentration the higher the TOC level and the less clean the water sample is.

Depending on the cleanliness of the water under test and the methods used different carbon dioxide concentrations are to be expected in the carrier gas, from wastewater with mgms/l of organic carbon giving % levels of carbon dioxide to drinking water with y μgms/l giving ppm’s of carbon dioxide in the carrier gas.

Edinburgh Sensors is a division of Edinburgh Instruments, according to Mark Vosloo, CEO, “We are delighted that our high performance sensors products are delivering the speed, accuracy and reliability required by customers. Equally, our products are easy to integrate which makes it the product of choice.”

Affirmed under monitoring certification scheme (MCERTS)

Following a rigorous testing programme, Hach Lange’s Biotector B7000 Online TOC Analyser has been awarded the 200th product conformity MCERTS certificate by SIRA, the body that manages the MCERTS scheme on behalf of the Environment Agency.

The Biotector B7000 is the latest Hach Lange product to achieve MCERTS in a line that began with the company’s portable and online samplers, which were awarded a certificate at WWEM 2008. This latest certificate confirms that the B7000 complies with stringent MCERTS performance specifications across three ranges (0–20 mg/l, 0-1,000 mg/l and 0-10,000 mg/l) and is considered suitable for use on treated wastewater, untreated wastewater, surface water, estuarine and coastal water applications.

Presenting the certificate on behalf of the Environment Agency, Paul Wiggins said: “The purpose of the MCERTS scheme is to assure the quality of environmental monitoring, by providing instrument users with confidence that certified equipment is capable of producing the quality of data that we require. However, the success of the MCERTS scheme could not have been achieved without the support of manufacturers such as Hach Lange.

“We recognise that certification represents an investment in time and resources which can sometimes be hard to justify when an instrument is already a market leader, but we believe that the attainment of a certificate will provide marketing advantage and demonstrate that a manufacturer is committed to quality. I congratulate Hach Lange on the achievement of this milestone certificate and thank them for their continued commitment to MCERTS.”

In the past, the Environment Agency conducted a large amount of industrial environmental monitoring, but in recent years this responsibility has shifted to the process operators themselves, and the MCERTS scheme is helping to ensure that the quality of monitoring remains high. Nevertheless, Matthew Dillon, UK & Ireland Sales Director at Hach Lange, says “As a manufacturer we invest heavily in the development of instruments and analysers that are robust, reliable, accurate and simple to use. However, it is extremely important that the recommended maintenance and calibration procedures are followed assiduously (and our service team can help with that, if necessary) because failure to do so would threaten the quality of data and would not be acceptable to the Agency.”

To further support the quality of monitoring, Hach Lange regularly runs training workshops and can provide personal competence training for key staff so that users are able to obtain optimal performance from their Hach Lange instruments.

From a strategic perspective Matthew Dillon says “One of our key goals is to ensure that our customers are able to generate the highest quality data and we see the MCERTS scheme as an important contributor to that goal. At Hach Lange we aim to offer the widest range of MCERTS products on the market; we already have a good number of certificates and we currently have a variety of products undergoing MCERTS evaluation. These include the SC1000 Digital Controller with sensors for pH, dissolved oxygen, ammonium and turbidity, and portable devices such as the HQD range of electrochemical instruments for pH, conductivity and dissolved oxygen.”

• All the products mentioned above will be on display at WWEM 2012 (Nov'12 Telford GB - stands 94,95 & 96) along with W.T.O.S. - Hach Lange’s highly successful wastewater treatment optimisation solution.

Low running costs for TOC

Improvements in combustion technology have further reduced day-to-day running costs for the multi N/C® TOC analyzer from Analytik Jena. This high performance analytical instrument combines low-maintenance technologies for sample digestion with an environment-friendly low consumption of consumables such as gas and power, as well as robust engineering and a long service life.

A re-designed, smaller combustion tube results in reduced consumption of the catalyst filling, leading to exceptionally long combustion tube lifetimes. High combustion temperatures up to 950°C provide quick and reliable digestion of even the most stable compounds and for the most challenging applications.

With the patented VITA® flow control system both automatically controlling gas consumption and providing long-term instrument calibration, ongoing maintenance requirements costs are minimised, meaning more time can be spent on carrying out analyses. The corrosion-proof Focus Radiation NDIR detector not only ensures reliable results and but also provides high stability throughout the lifetime of the instrument.

Analyser for clean water applications

The System-C Online TOC Analyzer from Biotector safeguards sensitive processes in clean water applications. The lightweight and portable System-C analyzer is the low cost option for low range clean TOC analysis.

Following customer feedback, BioTector System-C was specifically designed and engineered to meet the requirements of clean water applications including Condensate Return, Cooling Water, Potable Water, Pharmaceutical Water (WFI) and Demineralized Water.

David Horan, CEO of BioTector Analytical Systems commented on the launch “One of our core philosophies at BioTector is that we listen to our customers and, by responding to the challenges they face, we have continuously expanded our range of products and built our reputation. System-C is one example of customer feedback that has developed into a new product to service a particular market segment. And the early signs of interest we’ve seen are already very encouraging.”

BioTector System-C for clean water applications offers process insights, process incident alerts, environmental monitoring, energy optimisation, product loss prevention, water loss prevention, boiler protection and plant protection.

System-C uses the same award-winning, patented technology that has given BioTector an international reputation for unparalleled accuracy and reliability combined. BioTector was established in 1995, has more than 1,000 applications in 40 countries and is the market leader in the USA. So you can use BioTector TOC measurement data with total confidence.

• We reported that two of the SFA Irish National Awards 2012 were presented to Biotector recently. 

Real-time TOC tightens effluent control at Greencore

Author: Dr Patsy Rigby, Hach Lange, UK

A food manufacturing facility in Selby (GB) has installed a new continuous TOC (Total Organic Carbon) monitor, ‘the BioTector’ which has dramatically improved the site’s capability to refine and improve the plant’s wastewater treatment process. As a result the plant is better able to quickly respond to changes in the influent.

Greencore Foods is a leading player in the food processing industry and the group’s Grocery division is one of Britain's leading manufacturers of bottled recipe products (including cooking sauces, pickles, dips and soft drinks, producing 200 million jars per annum across 800 product lines). Operating from a site at Selby near York, it produces a wide range of both branded and retailer branded products across key market sectors. The facility has received considerable investment in the last 10 years and now boasts some of the most modern, hygienic and efficient production facilities in the country, achieving the prestigious AIB accreditation and being placed in the 'superior' category.

The Selby site is operated on a continuous improvement basis with its own dedicated wastewater treatment plant to monitor and control effluent quality and minimise costly discharge fees.  Effluent from the food manufacturing industry contains an array of inorganic salts and organic components which enter the waste stream in part from the intense wash down of processing tanks and lines during clean in place procedures for product changeover. Overload of organics on the effluent treatment plant adversely affects the efficiency of the treatment process. If the waste is not treated to the required standard, then the site will be unable to achieve the river discharge parameters that have been set by the Environment Agency.

The effluent treatment plant at the Selby facility is managed by a specialist team from Veolia Water IndustrialOutsourcing Ltd. Raw feed water entering the facility, is analysed for TOC  to control the strength of the feed transferred to the site effluent treatment plant.

As Greencore Environment Manager David Murtagh explains “In the past samples were manually collected from the site drains pit and transported to the laboratory at a second location. Given the geographical distance between sites this led to significant waste, both in terms of time and resources. We had a small team in the laboratory who performed a number of analyses on the delivered samples, which was quite labour intensive and delayed results. Even state of the art laboratory techniques still took too long for pragmatic purposes, preventing prompt feedback on the process.  Overall, this was not 21^st century and provided no direct information to control the effluent plant or provide an early warning of process issues. An alternative needed to be sought.

"A further key driver was the impending tightening of the consent to discharge to river by the Environment Agency. We needed more frequent, more detailed, prompt, accurate and reliable influent TOC data to help manage the effluent treatment plant more efficiently and provide feedback on the process which is the source of the TOC. We were wary of on-line TOC instruments due to poor experiences in the past; while they worked well on cleaner, particulate-free effluent samples, the high solids, fats, oils and greases, and variable TOC loads coming from raw influent was a major issue for delicate fine capillary tubing and valves, which typically caused instrument seizure.”

Historical issues

Traditional methods for analysis of TOC/COD/BOD were developed as laboratory systems based on UV exposure, wet chemistry or more aggressive digestion by catalysed combustion. While these provide an excellent basis for spot sampling within the laboratory where sample pre-treatment (e.g. by filtering) is controllable, the systems do not often translate well in a real process environment.

Raw effluent presents a series of challenges. With UV based systems, high salt loads can cause scaling of the UV light column creating problems or organic recovery. In high temperature combustion systems, salt loads as low as 0.5% can inhibit the persulphate digestion mechanism and deteriorate the lifetime of the catalyst, demanding excessive maintenance by replacement of the column. Sample volume is commonly restricted to less than 10µl and sample pre-filtering is necessary to avoid particulate blockage of tubing and multi-port valves such that particle size is restricted to <200µm. In a process environment, clogging of tubes with crystallised salts and particulates can demand instrument re-calibration every 2-3 days.

New Monitoring Technology

To achieve continuous, function in harsh process environments the BioTector from HACH LANGE uses a patented advanced oxidation process to offer aggressive breakdown of organics without thermal dependence.  This is achieved by exposing high pH reagents to ozone. Highly corrosive unstable hydroxyl radicals are generated and by a Two Stage Advanced Oxidation this enables the system to handle very large sample volumes without the need for syringe controlled dilution mechanisms (an additional route for blockage in traditional techniques). A self cleaning facility with micro-bubbles prevents particles becoming trapped and an inbuilt salt trap allows salt loads as high as 30% and calcium loads of up to 12% without dilution. Without the temperature resistant ceramic components of contemporary systems where salt can easily crystallise and cause blockage, the catalyst within the BioTector is attached to the exterior of the furnace, extending lifetime and facilitating easy replacement.

Unaffected by fats (internal tubing is protected by back wash), greases, salts and particulates up to 2mm diameter, a representative sample is achieved without pre-filtering allowing in excess of 80,000 continuous measurements per year. Maintenance requirements are minimal (6 monthly service is recommended with no calibration demands between service). The overall result is a 99+% uptime for the end user.

Summary

As Veolia’s Continuous Improvement Manager Marcus Hardiker explains “All previous concerns regarding the use of an on-line TOC meter were addressed with practical solutions. The instrument takes samples from the raw effluent that is fed to the site's treatment plant. However, we needed the sample to be as representative as possible and therefore no in-line filters were installed in the sample line. The sampling arrangement was very carefully engineered by the specialist team in order to deal with the site's unique type of effluent containing high sand and silt content.

"The signals from the BioTector unit have been integrated into both Veolia Water's effluent plant control system and Greencore’s own data acquisition system.  Veolia use the analysis to control the strength of feed transferred to the site effluent treatment plant. Any loads that exceed a pre-determined level are diverted to the site calamity tank. This control has enabled the performance of the effluent treatment plant to be greatly improved.

"The signals from the TOC meter are also transmitted to Greencore’s production areas, and the on-line data is visible for process personnel who can now see the effect that their activities are having on the effluent loads being discharged to the site treatment plant. Greencore has also linked the on-line results provided by the BioTector to an alarm system so that production personnel know when the TOC levels have increased - thus enabling them to react much quicker and thereby identify and address any issues as they arise."

With tailored solutions to match client needs, BioTector is simple to use and can reduce operational costs, avoid downtime and provide greater insight into processes for true real time control. 

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