Wastewater in Developing Countries

Numerous developing parts of the world contend with a high incidence of infectious disease because of poor drinking water quality and poorly functioning wastewater systems. Leaks and contamination of either system come from faulty or missing infrastructure, meaning distribution pipes, collection pipes, treatment facilities, and disinfection methods. Because of serious health threats to humans, many developing countries that already struggle with poor infrastructure make wastewater treatment their priority. The World Health Organization (WHO) has warned that the problem will get worse in developing countries. Because these places have clean water shortages, wastewaters substitute for treated water for irrigation, fishing, and cleaning clothes.

Sustainable wastewater treatment refers to the production of energy from the wastewater treatment process. This method of energy production offers an opportunity for developing countries for two reasons: the efficiency in converting biomass’s chemical energy to other forms of energy, and low cost compared with other energy technologies. Sustainable wastewater treatment therefore relieves two problems that plague many developing parts of the world: energy and waste management.

Nonindustrialized countries have a great need for inexpensive, easyto- build waste treatment technologies. Some of these countries have adopted inventive and sustainable solutions to waste treatment. The Internet reporter Andrea Millar provided an example in a 2008 article: “A Kenyan jail has confronted the issue of its waste production by creating a sustainable wastewater treatment facility staffed by inmates and designed by both local and international organizations. Rather than employ hightech engineering, the bulk of the [treatment is] handled by natural processes in the facility’s man-made wetlands. Acting as a vast filtration system, the sustainable processes of anaerobic microbes convert human waste into materials for biogas and water for use on the jail’s vegetable fields.” Millar’s example illustrates a situation in which wastewater handling is done in a manner that requires no energy input at all other than a small amount of manual labor.

The next step in sustainable wastewater use involves methods for producing energy. Treatment plant anaerobic digesters offer the most efficient way to make energy-containing methane gas, but some villages may not have the funds to build a new plant from the ground up. A waste treatment pond offers an inexpensive option because it contains conditions similar to those found inside treatment plant anaerobic digesters. Treatment ponds contain anaerobic activity in the deepest parts of the pond where aerobic bacteria have depleted the oxygen. Anaerobic bacteria live naturally in these types of places so setting up a wastewater treatment pond carries little expense. Methane gas drifts up from the bottom of the pond and can be captured and piped to an energy-generating plant so that the pond produces energy rather than consumes it.

Some ponds tend to grow heavy mats of algae on the water surface. Rather than spend efforts to get rid of the algae, workers remove the algae layer and add it to a small anaerobic digester to produce heat. In fact, treatment ponds provide the same advantages of mechanical anaerobic digesters: They help in waste management and treatment and recycle nutrients. One disadvantage of ponds compared with closed anaerobic digesters comes from odors emitted by the bacteria in their normal digestion of organic matter. The odors do not cause a health problem, but smell unpleasant.

R. Otterpohl wrote an online article in 2007 for the Swiss Federal Institute of Aquatic Science and Technology describing new processes for wastewater treatment that seem suited for developing countries: “The conventional wastewater management concept, consisting of a waterborne wastewater collection system leading to a central treatment plant, has been successfully applied over many decades in densely populated areas of industrialized countries . . . However, the appropriateness of this model in the context of developing world cities must be questioned, given the urgent need for affordable, sustainable infrastructure. During the last decade, various researchers and institutions, including the World Bank, have started to consider the decentralized wastewater management approach as an alternative to conventional centralized systems, but these approaches have struggled to gain acceptance.” Part of the resistance comes from the worry that treatment plants intended for the use of only one or two towns might not be as efficient to run as big centralized wastewater treatment plants. But small, decentralized treatment plants also offer advantages to communities, as follows:

1. smaller treatment systems tailored to a community’s specific needs
2. experimentation with different wastewater treatment methods
3. reduces accidents that may occur in long-distance wastewater shipment
4. increases opportunities for treated water reuse
5. makes incremental changes and improvements manageable

 Today, the Engineers Without Borders-International (EWBI) organization helps communities in developing regions adopt new technologies to improve their health, income, and lives. The EWBI stresses sustainable methods in energy use, water management, and native natural resource conservation. EWBI engineers and other volunteers help disadvantaged communities build needed structures and teach residents basic engineering skills for future projects. The founder of the Engineers Without Borders-United States, Bernard Amadei, revealed his view of the organization’s purpose in a 2007 interview with the correspondent Spencer Michels. Amadei described San Pablo, Belize, as a village “where I noticed a lot of little girls, young girls, who were carrying water—that was their job—from the river to the village, back and forth, back and forth. And as a result, they could not go to school. It broke my heart. And I decided I was going to do something about it.” EWBI develops projects with a community, not for it, so that the community solves its own environmental engineering needs. EWBI helps train residents how to build a structure, how to fix it, and how to keep it running.

Developing countries therefore have options for the type of wastewater treatment they choose. Because of the health needs for safe wastewater management and the need to produce inexpensive energy, sustainable wastewater systems are ideal for developing parts of the world.