Feb 26, 2024

Next level dewatering for wastewater

Wastewater treatment plants are essential for our modern lives. But how can their operation be continuously advanced and improved? What has long been a challenge in terms of optimization has now been achieved: the automatic control of decanters for sludge dewatering. The smart solution from GEA Intellicant operates these decanters better than humans were previously able to. Christian Schramm, product manager commercial for Digital Products at GEA, told us more about the full potential of these smart machines in an interview.

"Let’s smarten up your decanter!“ This is what GEA Intellicant offers to wastewater treatment plant operators worldwide. Our interviewee Christan Schramm has been part of the development team for around two years.

Mr. Schramm, GEA Intellicant – What is it?

GEA Intellicant is an intelligent system that monitors decanters for sewage sludge dewatering and automatically optimizes them based on the data it collects. And it does so in real time and continuously. With this system, the decanter is automatically operated at the optimum operating level at all times. For sewage treatment plant operators, this means higher dry substance values, lower costs, less effort and a safer process.

Will GEA Intellicant be the breakthrough in the automation of decanters in wastewater treatment plants?

There have been attempts to automatically optimize decanters, but the principle stands and falls with the quality of the sensor data and the ability to analyze the process parameters continuously in real time and reliably over the long term. And it is only now that sensor technology is ready. But as important as sensor technology is, it won't work without process expertise. After all, the key question is: How to interpret the sensor data? How can decanters be optimally adjusted? This crucial process intelligence now comes from GEA – and Intellicant uses it to make GEA decanters in wastewater treatment plants more intelligent. Hence the name Intellicant.

Where is Intellicant today and who is behind it?

For around two years now, I have been part of the team that launched the Intellicant project in mid-2021. Our Intellicant team in Oelde, Germany, works closely with the Automation and Smart Services and Process Technology & Innovation departments. With success – while the smart system is already proving itself at a plant in Germany, it is currently being commissioned in another plant in Denmark. Other countries and wastewater treatment plants will follow.

What was the core problem behind the development?

The product that is fed into the decanter is subject to permanent changes, for example the parameters of temperature, rain, even major events, but also the kind of local industry all have an influence on the composition of sewage sludge. The decanter must therefore be constantly adjusted in order to work at the optimum operating point. Today, this is handled by taking several samples a day to check the most important value: the dry substance of the so-called solids. However, the value is only available after half an hour. If the sample shows that the decanter settings need to be adjusted, this time has unfortunately already been lost from an economic point of view. GEA Intellicant checks the important parameters permanently, with real-time monitoring of the process – every second is virtually a data point.

“If we look for example at medium-sized waste water treatment plants, 1% more dry matter can mean savings of up to 60,000 euros per year.”

Christian Schramm

product manager commercial for Digital Products, GEA

This is how GEA Intellicant keeps the decanter at the optimum operating point: Three types of sensors measure relevant process data and the VO software evaluates the data directly and controls the decanter for optimum performance.

How does GEA Intellicant manage real-time monitoring?

Intellicant consists of a sensor package and a software, the “Virtual Operator.” The sensor package monitors three critical process parameters in real time: the solids concentration of the feed, the turbidity of the centrate and the dry matter of the solids. This sensor data is transmitted to the Virtual Operator via a local network connection. It is integrated into the decanter's control system and reacts automatically and intelligently to the incoming data.

What does this mean as a result – how can a decanter in wastewater treatment plants lower costs? 

Decanters play an important role in the final step, dewatering. Here, decanter centrifuges are used to remove as much water as possible from the sewage sludge. In many cases, what remains has to be disposed of as hazardous waste in mono-incineration plants. For every ton that leaves the plant, up to 150 euros have to be paid in disposal costs, depending on country and respective plant. The lower the water content, the lower the weight, the lower the costs. An automatically optimally operated decanter therefore not only saves work but also money. Even 1% more dry matter makes a big difference: After dewatering by centrifuge, the dry substance of the filter cake is usually around 25%. If I can increase this 25% by just one percentage point to 26%, this means annual savings of 35,000 to 60,000 euros in disposal costs for a medium-sized wastewater treatment plant – pure disposal costs.

To make this completely transparent for our customers, we provide them with a monthly report. This shows them what the operation of their decanter with GEA Intellicant achieves in terms of process performance and costs. They can also identify influencing factors in this diagram, such as internal process modifications which required a decanter shutdown or rainy days.


"It costs much more to not operate a decanter optimally over a certain period of time, than purchasing GEA Intellicant."

Christian Schramm

product manager commercial for Digital Products, GEA

GEA Intellicant offers its customers an average increase in dry matter of at least 1%. Performance is made available to customers transparently in the form of a monthly report.

How long does it take for GEA Intellicant to pay off? 

The first step is to upgrade the existing GEA decanter. The costs for the sensor package, installation and initial set-up vary depending on the complexity and sensor requirements. However, in most cases these investments can be amortized within the first year after commissioning the system. Other effects, such as the significant reduction in workload for staff, are not even taken into account.

Why is GEA Intellicant also an effective means of combating shortage of skilled workers?

Unfortunately, personnel who know the process and can really operate decanters are becoming increasingly scarce. Due to the shortage of personnel, these rare specialists are not only working at the decanter but have also a lot of other important tasks inside the plant. This can easily lead to staff shortages – but these can be significantly eased with GEA Intellicant. 

I would like to cite an example here from one of our customers: One of two operators was absent for several weeks. The remaining operator was very happy to be able to switch on our smart system and know that it was working. OK, that's how it works for now. During this time, GEA Intellicant was a considerable relief in the daily work of the remaining operator. But even after that – with full staffing levels – GEA Intellicant provided real relief. Over a short period of a few months, the utilization rate of GEA Intellicant was increased to 100%. Today, this customer runs his decanter exclusively with the Virtual Operator – a success that makes us happy.

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