Generating energy from wastewater with Berghof Membranes’ AnMBR technology

Antonio Sempere Serrano, global sales director at Berghof Membranes, tells us about the firm’s anaerobic wastewater treatment solution and how the technology, which has gained renewed interest in recent years due to a global focus on sustainability, can help industries generate their own energy and cut costs

Antonio Sempere Serrano, global sales director, Berghof Membranes
Antonio Sempere Serrano, global sales director, Berghof Membranes

F+S: Tell us more about Berghof's AnMBR technology.

AS: Treating highly polluted industrial wastewater can be challenging, but our AnMBR process is up to the task. With its specific design to handle high concentrations of mixed liquor suspended solids, ranging on average from 15 g/L to 35 g/L, the process is efficient and cost-effective for operators. Our proprietary membrane chemistry and tubular geometry allow a steady permeating flow, even when dealing with challenging anaerobic sludges. The tubular membrane operates in crossflow – this results in increased fouling control and eliminates the need for an additional gas application to bring shear forces to the membrane surface.

We can operate our membrane elements at high organic loads and achieve over 98% COD removal. Additionally, the ultrafiltration membrane produces high-quality permeate that can be reused. This process is not only highly efficient and effective, but it is considered a great choice for various applications as well.


F+S: How is AnMBR technology sustainable?

AS: AnMBR represents a significant leap ahead when it comes to corporate sustainability targets. Reuse of highly polluted wastewaters can be achieved easily with AnMBR technologies by using standard light post treatments like reverse osmosis in many cases. Anaerobic MBR is the most efficient and robust technology in terms of conversion from COD to energy, contributing dramatically to industry decarbonization.

In the focus of a membrane system, there is always economy, quality, and security. The operator wants to benefit from superior effluent quality. Berghof Membranes’ AnMBR process provides effluent that is free of solids and bacteria. It achieves the highest COD reduction possible.

You can safely discharge it or simplify post-treatment to make your effluent ready for reuse.

When looking at the economy, there are the operational costs of a system. In an AnMBR process, retaining organic solids completely and extending solids retention times (SRTs) can significantly improve COD/ BOD elimination. An AnMBR system has a very high tolerance to total suspended solids (TSS) and fats, oils, and grease (FOG).

This simplifies pretreatment and maximizes the conversion of organic matter into usable biogas.

The maximized biogas production helps to improve the energy footprint of the AnMBR wastewater treatment system.

The overall performance is another economic pillar. AnMBR is more effective compared to traditional anaerobic processes, such as granular sludge bed reactors, even under difficult conditions. For example, high salinity, high temperatures, high concentrations of suspended solids or FOG, and the presence of toxins. They would inhibit granulation and biomass retention or reduce biological activity in other anaerobic technologies.

The third pillar regarding the economy is the low sludge production and chemicals consumption of an anaerobic MBR. Eliminating a mandatory dissolved air flotation as pretreatment can significantly reduce chemical consumption and avoid large amounts of sludge that need to be treated on site or transported away, resulting in reduced operation costs. When we are looking at process reliability – which is a huge security factor for the operators -our robust tubular UF membranes support a reliable lifecycle by avoiding biomass washout. This results in the ability for rapid start-ups, specialized microbial communities, and robustness against organic or toxic shocks.


The Seymen Landfill project constructed by Lidya Ozca for the Istanbul municipality. -

F+S: Does your AnMBR technology generate energy during the water purification process?

AS: Yes. This energy is produced in the form of biogas and can be converted to electricity, biomethane or even hydrogen depending on the selected technology path. AnMBR processes biogas as a byproduct.

So, our AnMBR technology provides an environmentally friendly source of energy, for use as heat and electricity. If upgraded into biomethane, it can be utilizable, for example, as combustion fuel or as a substitute of natural gas supply for households and industrial facilities.


F+S: How is Berghof's AnMBR technology currently being used?

AS: It is being used in multiple industries such as distilleries, confectioneries, bioethanol production, and dairy factories.

Looking specifically at the latter, treating dairy wastewater can be very challenging, but with the right technology, it can be done reliably and efficiently.

The wastewater’s variability in day-to-day dairy operations, high organic loads and the presence of FOG, calcium and potentially toxic or inhibitory components from cleaning operations, make it a difficult task. An experienced team can handle these challenges with ease and ensure a stable treatment process. In partnership with Complete Filtration Resources, an AnMBR process with Berghof technology has been successfully developed and installed at a local dairy factory in Wisconsin, USA.

The implementation of the AnMBR has had an extremely positive impact on the overall performance of the treatment plant.

By separating the low- and highstrength streams and directing them to either the aerobic MBR or anaerobic MBR, the overall performance of the system is greatly optimized. While 40% of the flow and 70% of the organic load are currently treated in the AnMBR, a significant portion of the organic load is converted into recoverable energy in the form of biogas.

Furthermore, since a 550kW biogas engine has been installed, the anaerobically produced biogas fuels a generator that produces about four million kWh per year. It covers more than twice the energy required for the AnMBR and saves US$20,000 to US$25,000 per month in energy cost.

Subsequently, the company is saving up to US$150,000 per month in costs that would otherwise be incurred without the AnMBR wastewater treatment system. The return on investment is less than four years. The operator reported benefits like the capability of water reuse, significant energy cost savings and other sources of savings.

The responsible, environmentally sound treatment of 1,900 m3/d of wastewater is also a point of pride for the butter manufacturer, as it reinforces a key brand attribute – an environmentally sustainable business model. In a nutshell, the company produces three times more butter than it did 15 years ago, while using less energy, water and land.


F+S: What does the future hold for Berghof and its AnMBR technology?

AS: We are convinced that the recovery of resources will be the driving force behind economic stability. We are therefore looking at how we can help industry to implement sustainability, reuse recyclable materials and prevent contaminants from entering the environment. On the product side, the longevity of the membrane modules, as well as their economical operation, are being emphasized. On the process side, we are already moving toward energy neutrality with the AnMBR.

This is particularly important for achieving a neutral carbon footprint within the framework of the legal requirements for the industry.


About the author

Antonio Sempere Serrano, global sales director at Berghof Membranes spoke to Mankirat Kaur, editorial assistant at Filtration+Separation magazine.


This article first appeared in the March 2024 issue of Filtration+Separation magazine. To read the full issue, click here