Endress+Hauser, a global leader in process automation and measurement instrumentation, believes that water quality testing in the field and laboratory play a crucial role in achieving Sustainable Development Goal 6 (SDG 6) by identifying potential health and environmental risks.

Hennie Pretorius, industry manager: Water and Wastewater, Endress+Hauser in Africa

“When it comes to water quality and SDG 6, the goal emphasises not only access to clean and safe drinking water but also the importance of improving water quality in general. Poor water quality can have significant negative impacts on human health, ecosystems, and the economy. While laboratory tests for water quality are sometimes mandatory and viewed as an accurate alternative, water quality field tests are often more convenient, cheaper, and have real-time monitoring capabilities,” explains Hennie Pretorius, industry manager: Water and Wastewater, Endress+Hauser in Africa.

Drinking water quality

There are some disturbing findings in the Blue Drop Watch Report:

• Most water treatment works (WTWs)do not produce water compliant with SANS241
• 51%of WTW shave poor to bad microbiological water quality status
• 71% of WTWs failed to achieve chemical compliance

Pretorius adds that the majority of microbiological water quality monitoring is conducted by laboratories, while most chemical water quality monitoring can be done in the field. “It is possible to do chemical water quality monitoring remotely, with all the data updated in real time. This can provide an early warning when something goes wrong. Reports on water quality compliance or noncompliance can be generated with ease.”

Parameters that are frequently sampled or monitored for surface water quality include: turbidity, dissolved oxygen, pH, free chlorine, conductivity, biological oxygen demand (BOD), and temperature.

“Dissolved oxygen represents the amount of oxygen in water and is one of the more important parameters for surface water. This is because a decline in oxygen is a threat to aquatic life and maybe caused by chemicals(pollution)reacting to the oxygen or biological compounds like algae absorbing the oxygen. BOD is also important because it gives the fastest indication of sewage in a water source,” states Pretorius.

Effluent water quality

The 2022 Green Drop Report also paints a worrying picture–specifically, that 334 wastewater treatment works (WWTWs) were identified to be in a critical state. That’s nearly 40% of all WWTWs.

“Endress+Hauser can provide in-and outflow water quality monitoring. Inflow quality monitoring can help determine the biological and hydraulic loading of a plant and can give an early warning if the effluent is outside normal parameters. This is particularly helpful if there is a buffer tank or diversion system that can prevent harmful chemicals from entering and killing microbes in a WWTW. If the hydraulic loading is high, steps can be taken to avoid over-treatment of the effluent,” explains Pretorius.

Endress+Hauser has extensive experience in monitoring effluent–both for the private and public sector. As regulations become more stringent, it is essential to monitor all effluent parameters in real time (where possible) and collect true representative samples for confirmation using lab testing.

Remote liquid analysis

Endress+Hauser’s Liquiline transmitter platform is based on Memosens digital technology that can monitor and log up to eight different parameters in water and wastewater. Memosens sensors are connected with the Liquiline transmitter, which automatically recognises the sensor type and reads the information stored in it. Furthermore, many Liquiline devices–including analysers and samplers–can operate multiple Memosens sensors in any combination. With Memosens digital technology, there is minimal signal interference and greater accuracy. Remote monitoring is done through the Netilion system.

Netilion is an award-wining, cloud-based, industrial internet of things (IIoT) ecosystem designed for industrial processes. It connects the physical and digital worlds to send valuable information from the field straight to a phone, tablet, or other device. It is not only confined to equipment from Endress+Hauser, but can provide data from different instrumentation brands.

Pretorius believes that this technology is of huge value for a municipal manager, who may be responsible for a number of WTWs or WWTWs in an area. “The manager can view water and wastewater quality remotely via an app on their phone and will receive alerts if any parameters are out of spec. With industrial WWTWs, an environmental manager can receive effluent quality data in a central location and monitor how well each plant is working. This prevents unnecessary time and travel to plants.”

Endress+Hauser has launched preconfigured panels that combine field instruments, edge devices, and software for remote monitoring and maintenance. These panels are also equipped with Netilion. They provide a flexible, plug-and-play solution that can measure parameters chosen by the customer.

Further, the company’s spectrometer offers reliable, real-time measurements of multiple parameters like chemical and biological oxygen demand equivalent, turbidity, nitrate, and spectral absorption coefficient in a single device. “This type of technology is typically only available as laboratory equipment but can now be used in the field. It can be quickly adapted to a specific application through pre-installed analysis models,” says Pretorius.

Maintenance

Regular maintenance work is essential to minimise unplanned and costly downtime on measuring equipment. “The Liquiline transmitter is a plug-and-play set up that speeds up work and minimises process downtime during sensor maintenance. It also provides additional information around the health of the sensor,” says Pretorius. Most Endress+Hauser measuring devices have a unique diagnostic, verification and monitoring function known as Heartbeat Technology. These increases measuring reliability by monitoring the health of the transmitters, providing diagnostics of the sensors, and then is suing notifications around device failures and maintenance requirements.

“For example, electrolytes in the digital free chlorine sensor need to be replenished and the sensor must be calibrated after a certain period of time. Fair warning is given to technicians, thereby ensuring that there is never a ‘dead space’–where no readings are provided due to a broken measuring device,” explains Pretorius.

All of Endress+Hauser’s flow meters have built-in verification techniques traceable to known metrology standards. This is a mandatory requirement for when WTWs and WWTWs are applying for Blue Drop and Green Drop status. The verification can be done remotely, which is a necessity for water utilities whose services stretch over large areas.

“We are focused on optimising maintenance efforts, to ensure that our products always give reliable information that help streamline processes,” states Pretorius. Endress+Hauser also has a considerable Service Department that works according to service contracts or callouts.

“The water and wastewater sector is cost-sensitive, and sometimes instrumentation ends up at the bottom of the list; however, monitoring a process will yield better results and optimise a plant, saving money in the long term. Endress+Hauser has a huge toolbox of solutions for the water and wastewater sector, and we are always ready to assist,” concludes Pretorius.