9th August 2022 | pilot plant for an Electroactive Wetland

Constructed wetlands (CWs) are one of the conventional technologies for wastewater treatment which is acknowledged as an aesthetic and eco-friendly technology to promote ecological balance. It has furthermore been widely adopted as decentralized secondary wastewater treatment technology in several parts of the globe. However the large land area requirement of CWs for sewage treatment of 4-5 m2 per person restricts their implementation in the cities and urban communities.

To address this issue the Indian scientist Dr. Asheesh Kumar Yadav has introduced a novel integrated biological wastewater treatment technology called Constructed Wetland Integrated Microbial Fuel Cells (CW-MFCs) in 2010. This merger was possible due to similar stratified gradients in both CWs and MFCs, which means presence of atmospheric oxygen in upper substrate layers (aerobic region) and absence of oxygen in the bottom part (anaerobic region). The conductive material acts as an electron acceptor in the oxygen-deficient lower regions, thus accelerating the biochemical processes of degradation. Further these electrons are collected with the help of solid charge collectors as shown in below figure from the lower region (anode) and transferred to upper region (cathode) through the help of copper wire. In the upper region these electrons are reduced to H2O by reacting with available atmospheric oxygen. In this whole process of electron transfer we can also harvest bioelectricity (see below figure). Thus, this new approach not only reduces the area requirement of CWs by at least one half but also it has the ability to produce bioelectricity. In recent years CW-MFCs have been well documented at lab level, but there has been little depth in pilot experimentation.

Currently, Janisch & Schulz are planning to set up a pilot scale electroactive wetland unit in collaboration with Dr. Asheesh and his Ph.D. student Ms. Yamini Mittal at a longtime customer of the engineering company. We are very grateful to all involved in the cooperation. This experiment will further help in making a comparative assessment of treatment performance between electroactive wetlands with conventional constructed wetlands in real field.