Anaerobic technology

Anaerobic waste treatment has been practised for over a century.¹ Why, then, should we publish a themed issue on this topic? Why even perform research on a process that has been used effectively for the production of methane from waste since the late 1800s?

The answer is simple: the world has become resource-constrained. Global energy use and population are rising.^2,3 Greenhouse gas concentrations are rising.⁴ Infrastructure is aging and failing.⁵ We can, and we argue we must, be more thoughtful and creative when it comes to using our resources and extracting value from waste. Luckily, we are not alone in this opinion. In fact, this themed issue highlights just the tip of the iceberg, so to speak, of the excellent and exciting research being performed in the area of anaerobic treatment. We have gathered several review articles focused on issues encountered by mainstream anaerobic treatment: greenhouse gas production and the need for downstream polishing technologies. We have collected papers that advance knowledge in the area of resource recovery (fatty acids, hydrogen gas, electricity) and the concept of waste as a biorefinery feedstock, and which address engineering advancements in anaerobic treatment with anaerobic membrane bioreactors, the amendment of conductive materials, and smarter low-temperature and side-stream processing. We have also gathered two papers focused on the anaerobic treatment of so-called contaminants of emerging concern (CEC) – in this case, antibiotic resistance genes. We are excited to see where the field of anaerobic waste treatment is going, and are optimistic about the trajectory, given the range and diversity of research being pursued by scientists and engineers.

Nevertheless, we know that more work is needed to be able to successfully deal with resource constraints in the face of growing need. In particular, more research on CEC degradation/transformation is needed, especially as it relates to “new” treatment processes such as anaerobic ammonia oxidation and high-rate anaerobic treatment. More research on developing novel reactor designs to better utilize our ever-expanding knowledge of anaerobic microbiology is needed. Finally, more pilot- and full-scale research is needed to enable the predictable and robust implementation of these new processes, including work on reliable and efficient greenhouse gas recovery.

We hope that you find this collection of papers useful and inspiring, just as we have, and invite you to join us in searching for more solutions.

References

1. L. G. Rich, Unit processes of sanitary engineering, Wiley, New York, 1963.
2. https://data.worldbank.org/indicator/sp.pop.grow .
3. https://www.eia.gov/todayinenergy/detail.php?id=32912 .
4. https://www.eea.europa.eu/data-and-maps/indicators/atmospheric-greenhouse-gas-concentrations-10/assessment .
5. 2017 Infrastructure Report Card, American Society of Civil Engineers, 2017.

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