What is an Anaerobic Membrane Bioreactor (AnMBR)?

An anaerobic membrane bioreactor (AnMBR) is a sophisticated wastewater treatment system. It merges two key processes: anaerobic digestion and membrane filtration. Anaerobic digestion employs microorganisms that break down organic matter in the absence of oxygen, producing biogas and other byproducts. Membrane filtration then separates solids, bacteria, and other pollutants using a semi-permeable membrane, resulting in cleaner water. This combination allows for effective treatment of complex pollutants.

Why is Tetrahydrofuran (THF) a concern in pharmaceutical wastewater?

Tetrahydrofuran (THF) is a cyclic ether used as a solvent in drug manufacturing. It's a significant concern in pharmaceutical wastewater due to its high biological toxicity and resistance to degradation. This means it can persist in the environment and pose risks to aquatic ecosystems and human health. The study focuses on the AnMBR's ability to remove THF, highlighting the need for technologies that specifically address this challenging pollutant.

Why is the AnMBR so important for treating pharmaceutical wastewater?

The AnMBR is crucial for treating pharmaceutical wastewater because traditional methods often fail to remove complex pollutants like THF efficiently. The AnMBR offers several advantages: it can degrade complex organic pollutants through anaerobic digestion, effectively remove solids, and operate efficiently with high organic loading rates and short hydraulic retention times (HRTs). This makes it a promising alternative for cleaner effluent.

What is the importance of Hydraulic Retention Time (HRT) in the context of this study?

Hydraulic Retention Time (HRT) is the amount of time wastewater spends in the reactor. In the study, maintaining an HRT above 24 hours was critical for effective removal of Chemical Oxygen Demand (COD) and Tetrahydrofuran (THF). When the HRT decreased, the AnMBR's performance declined, as the microorganisms did not have sufficient time to degrade the pollutants. This highlights the importance of optimizing operating conditions for efficient wastewater treatment.

Why is the AnMBR technology a promising path forward?

The significance lies in its potential to provide a sustainable solution for pharmaceutical wastewater treatment. The study's results demonstrate the AnMBR's ability to remove both Chemical Oxygen Demand (COD) and Tetrahydrofuran (THF) efficiently. This offers a promising alternative to conventional methods, contributing to environmental protection by preventing harmful substances from entering aquatic ecosystems and impacting human health. The study's insights contribute to the development of advanced wastewater treatment.

Microscopic organisms cleaning water

Can This Tiny Tech Clean Up Pharmaceutical Waste?

Avery Sinclair in Climate & Environment December 2025 • 5 min read.

"A pilot study explores how an anaerobic membrane bioreactor (AnMBR) can efficiently treat tetrahydrofuran (THF) in pharmaceutical wastewater, offering a sustainable solution."

The pharmaceutical industry, while vital for healthcare, generates substantial amounts of wastewater containing various pollutants, including antibiotics, solvents, and other chemicals. These pollutants pose a significant threat to aquatic ecosystems and human health if not properly treated. Traditional wastewater treatment methods often struggle to effectively remove these complex compounds, leading to their persistence in the environment.

Among the various pollutants found in pharmaceutical wastewater, tetrahydrofuran (THF) is a particularly concerning cyclic ether used as a solvent in drug manufacturing. THF is known for its high biological toxicity and resistance to degradation, making its removal challenging. Therefore, there is a growing need for innovative and efficient technologies to address the specific challenges posed by THF and other pharmaceutical pollutants.

In response to this need, researchers have been exploring advanced treatment methods, including membrane bioreactors (MBRs). This article delves into a pilot-scale study investigating the performance of an anaerobic membrane bioreactor (AnMBR) for treating THF-containing pharmaceutical wastewater. We will explore the AnMBR's efficiency in removing THF and other pollutants, as well as the factors influencing its performance, providing insights into its potential as a sustainable solution for pharmaceutical wastewater treatment.

How Does an AnMBR Tackle Pharmaceutical Wastewater?

An anaerobic membrane bioreactor (AnMBR) is an advanced wastewater treatment technology that combines anaerobic digestion with membrane filtration. Anaerobic digestion is a biological process where microorganisms break down organic matter in the absence of oxygen, converting it into biogas (primarily methane and carbon dioxide) and other byproducts. Membrane filtration involves using a semi-permeable membrane to separate solids, bacteria, and other pollutants from the treated water.

In the context of pharmaceutical wastewater treatment, AnMBRs offer several advantages over conventional methods. First, anaerobic digestion can effectively degrade complex organic pollutants like THF, which are often resistant to aerobic treatment. Second, membrane filtration ensures a high degree of solids removal, resulting in a cleaner effluent. Third, AnMBRs can operate at high organic loading rates and short hydraulic retention times (HRTs), making them compact and efficient.

Experimental Setup: A pilot-scale AnMBR system was set up to treat synthetic pharmaceutical wastewater containing THF at different hydraulic retention times (HRTs).
Key Parameters Monitored: The researchers closely monitored chemical oxygen demand (COD), THF concentrations, mixed liquor suspended solids (MLSS), mixed liquor volatile suspended solids (MLVSS), and extracellular polymeric substances (EPS).
Performance Evaluation: The effectiveness of the AnMBR system was evaluated based on its ability to remove COD and THF under different operating conditions.

The study results demonstrated that the AnMBR system achieved high COD and THF removal efficiencies under specific operating conditions. When the HRT was maintained above 24 hours, the system consistently removed over 95% of COD and 98% of THF. This indicates that the AnMBR system can effectively treat pharmaceutical wastewater containing THF, meeting stringent discharge standards. However, the study also revealed that reducing the HRT below 24 hours negatively impacted the system's performance. The COD and THF removal efficiencies decreased, suggesting that the microorganisms in the reactor did not have enough time to effectively degrade the pollutants at shorter HRTs.

A Promising Path Forward

This study provides valuable insights into the potential of AnMBR technology for treating pharmaceutical wastewater containing THF. The results indicate that AnMBRs can achieve high removal efficiencies for both COD and THF under optimized operating conditions. This makes them a promising alternative to conventional wastewater treatment methods, which often struggle to effectively remove these pollutants.

To fully realize the potential of AnMBR technology, further research is needed to optimize the system's design and operation. This includes investigating the effects of different HRTs, organic loading rates, and membrane types on the system's performance. Additionally, more research is needed to understand the microbial communities within the AnMBR and how they contribute to pollutant degradation.

Despite the need for further research, this study demonstrates that AnMBR technology holds great promise for treating pharmaceutical wastewater and protecting our environment. By investing in and developing these innovative technologies, we can create a more sustainable future for both the pharmaceutical industry and the planet.