Cut the Crap Out: Usage of Biotechnology in Sewage Treatment

The film Ang Babae Sa Septic Tank (2011) features the iconic scene in which Eugene Domingo falls into a septic tank for the movie she’s filming. Comedic as it may be, this particular scene gives insight into the wastewater treatment situation in the Philippines.

Just like in the film, most Filipino houses rely on septic tanks for domestic wastewater treatment. In actuality, only 5% of Filipinos have access to piped sewerage systems. The country currently faces a wastewater management crisis as only 10% of the overall wastewater generated by the population gets treated [1].

Now more than ever, we need to look into sustainable solutions to domestic wastewater management — biotechnology might be the answer.

Well, that’s a load of crap…

For centuries, biotechnology has been a mainstay in our society long before it was a thing. Biogas from treated organic wastes was being harvested as early as ancient Assyria and Persia. In the 17th century, Jan Baptista Van Helmont figured out that flammable biogas evolved from decaying matter. Sir Humphry Davy, who studied the anaerobic breakdown of cattle manure, formally correlated the methane produced with the decaying matter present in 1808. Thanks to their scientific breakthroughs, the first-ever digestion plant, which utilizes anaerobic technology, was built half a century later in Bombay, India [2].

Anaerobic biotechnology has evolved more than a hundred years since its development. Within the last few decades, interest in sustainable waste treatment has slowly started to gain traction. Scientists have observed that incorporating certain biological processes of bacteria into technology aids in the treatment of organic waste. In a large-scale system, it could help with the rapidly growing wastewater problem of communities.

Today, anaerobic digestion is widely considered an environmentally friendly technology for various organic waste, including sewage sludge. This revolutionary biotechnology is even utilized as a sustainable and low-cost solution to sewage treatment all over the world.

Get your crap together!

Utilizing the anaerobic digestion of bacteria is crucial to the success of biotechnology. The most popular biotechnology structure in circulation is the digester, a closed vessel [3]. Although digesters vary in shape and size, their principal function is to provide an enclosed, oxygen-free space for microorganisms to carry out their biological processes.

So the question stands — how exactly does anaerobic biotechnology work?

All bacteria employ the help of proteins and extracellular enzymes to digest nutritious materials from organic matter into fatty and amino acids and glucose [4]. For optimal digestion, various environmental conditions must be met, since different species have different requirements. In particular, some bacteria can perform biological processes even in the absence of oxygen. How cool is that?

Throughout the process, bacteria also create various byproducts [5]! First, is the biogas, which consists mostly of 40–70% methane (CH4), along with traces of carbon dioxide (CO2), hydrogen gas (H2), hydrogen sulfide (H2S), nitrogen gas (N2), and water vapor (H2O) [4]. Further refinement of said biogas has the potential to become a sustainable source of natural gas for electricity generation. Another byproduct created is the digestate, a nutrient-rich sludge made up of leftover solids and liquids after digestion. It can be further processed into anaerobic biomass, a good fertilizer for agricultural use.

An ongoing study sponsored by the Philippine Council for Industry and Energy and Emerging Technology Research and Development of the Department of Science and Technology investigates the prospect of using anaerobic biotechnology for sewage treatment. A pilot-scale Biological Nutrient Removal Technology (BNRT) is developed to process sewage into valuable resources and, at the same time, improve water quality [6]. With further research, the technology has the potential for large-scale waste treatment.

Anaerobic technology isn’t just reserved for domestic wastewater treatment. The versatility of this biotechnology allows for its application in various other fields such as food management, agricultural, and energy industries, among many others. Even NASA has invested in anaerobic technology for air recycling in oxygen-poor environments, such as space shuttles and possibly future Martian settlements [7]. The sky’s the limit (pun intended) with biotechnology!

Why should I give a crap?

In Metro Manila alone, an estimated PHP 9.4 billion will be saved in taxpayers’ money annually in preventing problems caused by contaminated water [8]. Leaving sewage untreated increases the risk of pathogens spreading and poses disease outbreaks. In addition to this, the growing consciousness of ecological concern should leave us wary of the negative impacts brought by excessive waste production.

Our sewage is a wasted opportunity when it shouldn’t be.

It’s beneficial for people and the local flora and fauna to have clean water readily available. Improving wastewater collection and treatment is necessary; it is a crucial component in attaining a high quality of life [9]. With the current waste management technology lagging behind the growing population, we need sustainable solutions now more than ever.

The integration of anaerobic technology into our current waste management facilities will surely be a challenge, but not entirely impossible. With more funding and institutional support invested toward anaerobic biotechnology research, self-sustaining communities will be within reach.

Biotechnology’s future in our country surely looks bright (but not exactly fragrant)! Picture this, imagine a future where septic tanks can be more than just swimming pools for Eugene Domingo!

Written by: Jana Garcia

Proofread by: Yovia Ogasawara and Lyra Tamayo

Art by: Jana Garcia

SOURCES

[1] ARCOWA. (2018). Wastewater management and resource recovery in the Philippines: current status and opportunities.

[2] A Short History of Anaerobic Digestion. (2012 September 14). Pennsylvania State Extension. Retrieved from https://extension.psu.edu/a-short-history-of-anaerobic-digestion (accessed on 2021 February 01).

[3] DeRouchey, J. M. (2014). MANURE/WASTE MANAGEMENT| Manure Management.

[4] Morales-Polo, C., Cledera-Castro, M. D. M., & Moratilla Soria, B. Y. (2018). Reviewing the anaerobic digestion of food waste: From waste generation and anaerobic process to its perspectives. Applied Sciences, 8(10), 1804.

[5] Spuhler, D. (2020). Anaerobic Digestion (General). Sustainable Sanitation and Water Management Toolbox. Retrieved fromhttps://sswm.info/arctic-wash/module-4-technology/further-resources-wastewater-treatme nt/anaerobic-digestion-%28general%29#:~:text=Biogas%20sanitation%20is%20the%20tre atment,and%20a%20nutrient%20rich%20sludge (accessed on 2021 February 01).

[6] Damalerio, R., Orbecido, A., Promentilla, M. A., Eusebio, R. C., Patacsil, L., & Beltran, A. (2021). Preliminary Investigation of an Installed Pilot-Scale Biological Nutrient Removal Technology (BNRT) for Sewage Treatment. In MATEC Web of Conferences (Vol. 333). EDP Sciences.

[7] Brewer, J. H. (1980). Anaerobic microbiology in the NASA space program. Infection, 8(2), S219-S220.

[8] Jalilov, S. M. (2018). Value of clean water resources: Estimating the water quality improvement in Metro Manila, Philippines. Resources, 7(1), 1.

[9] Ren, J., Ren, X., Liu, Y., Man, Y., & Toniolo, S. (2020). Sustainability assessment framework for the prioritization of urban sewage treatment technologies. Waste-to-Energy, 153–176.