In This Issue
The Bridge: 50th Anniversary Issue
January 7, 2021 Volume 50 Issue S
This special issue celebrates the 50th year of publication of the NAE’s flagship quarterly with 50 essays looking forward to the next 50 years of innovation in engineering. How will engineering contribute in areas as diverse as space travel, fashion, lasers, solar energy, peace, vaccine development, and equity? The diverse authors and topics give readers much to think about! We are posting selected articles each week to give readers time to savor the array of thoughtful and thought-provoking essays in this very special issue. Check the website every Monday!

Accelerating Innovation in the Water Sector to Meet Future Demands

Thursday, December 24, 2020

Author: Kimberly L. Jones

Access to safe and reliable drinking water is a basic human right, yet over 2.2 billion people do not have it (WHO/UNICEF 2017). A similar number live in countries experiencing water stress, which is expected to be exacerbated by an increase in global water demand—20–30 percent by 2050—driven by population growth, development, and changing consumption patterns (Burek et al. 2016). In addition, warmer air and water temperatures, along with changing precipitation patterns, increase water pollution, while extreme weather events may further weaken already compromised infrastructure. These challenges, if left unmet, will threaten future public health, food stability, ecosystem health, and economic growth.

Services to provide safe water are important to global economies. Water needs to be available, accessible, and treated to acceptable quality for its intended use (consumption, cooking, agriculture, energy). Total annual revenue for the US water and wastewater industry is over $139 billion, and the global water market is estimated to be over $500 billion (Maxwell 2013).

One would expect that such serious challenges in an industry as important as water, combined with the impact that water has on the economy, would incentivize innovations in related technology, institutions, and management. But despite pervasive, worsening stressors around water quantity, -\quality, and infrastructure, innovation in the water sector is very slow.

Barriers to Innovation in the Water Industry

To be innovative, an industry must value and invest in innovation. Industries such as automotive, entertainment, computing, and consumer goods value innovation because it drives profitable growth. It is counterintuitive that innovation in the apparel industry, for example, would be higher than in the water industry, which is so central to public health and economic growth.

But the water sector has inherent barriers to innovation: capital equipment has a long design life, plants tend to be large and centralized, and water institutions are regulation-based, risk-averse, and biased to inertial dominance of existing technologies (Kiparsky et al. 2013).

To meet the need for safe water amid myriad water resource stressors, the industry must shift focus from reliance on traditional water resources to alternative water resources such as desalinated seawater, ground-water, reclaimed stormwater, greywater, and treated wastewater, and develop protocols to expedite evaluation and implementation of novel treatment processes.

New and Sustainable Water Treatment Systems

As stressors on water quality and quantity worsen, conventional water treatment processes are increasingly unable to meet future water quality goals; they require high chemical and energy inputs, are complex to operate, create large waste streams, and are resistant to retro-fitting. Sustainable treatment processes are necessary to reliably remove current and emerging contaminants without creating a heavy chemical burden or high byproduct stream.

New treatment systems would include a mix of robust, efficient processes that are also low in both cost and energy requirements. The timeline between development and widespread deployment of novel treatment processes to treat these sources to acceptable quality must be reduced.

Alternative resources require treatment processes designed to deliver water services that are reliable, safe, accessible, affordable, and culturally acceptable in the face of climate change, population growth, development, environmental degradation, and regional conflict. This challenge requires investment in the development and implementation of next-generation water treatment systems.

State-of-the-Art Membranes

Next-generation water systems will include decentralized systems and low-cost community-based systems that complement or replace large centralized water infrastructure (Gleick 2003). An attractive unit operation for many of these applications is membrane filtration, as membranes can be used alone or as part of a multibarrier, component-based system that can be tailored to suit the intended use of the water. Membranes come in varying configurations, from tight, dense reverse osmosis (RO) membranes that reject most trace contaminants, to low-pressure membranes such as micro- and ultrafiltration.

Alternative resources require treatment processes designed to deliver water services that are reliable, safe, accessible, affordable, and culturally acceptable.

Traditional thin-film membrane systems are a mature worldwide industry with applications in the desalination of brackish and saline sources and incorporation in bioreactors. These polymeric materials represent the state of the art in membrane fabrication with their great transport properties, large surface area, small footprint, and relative affordability.

Membrane Research and Innovation

To meet the challenges of affordability, energy efficiency, and sustainability, issues such as concentrate disposal, fouling, and energy use have to be addressed. Membrane researchers have long chased the goal of reducing the energy cost of desalination—for example, by greatly reducing the energy use to nearly the thermo-dynamic limit—but scaling and concentrate disposal are still major issues.

A promising area of research in membranes is the development of novel materials that may disrupt the polymeric thin-film membrane industry. For example, the coupling of traditional membrane polymers with nanomaterials such as graphene oxide (Igbinigun et al. 2016) has shown promise by increasing permeability and reducing fouling.

Membrane distillation is also gaining popularity, as it operates at lower pressures than RO and at lower temperatures than traditional distillation processes. Researchers have developed innovative methods to embed light-absorbing nanoparticles in the surface to use solar energy to drive the distillation process (Dongare et al. 2017). Others have designed block copolymer–based materials with synthetic nano-channels to increase selectivity and permeability and reduce fouling of membranes (Sadeghi et al. 2018).

How to Accelerate Innovation?

These research findings could be transformative for next-generation water purification, but they often stall at the bench or lab scale. In the water industry, new treatment processes must undergo extensive evaluation and testing before being accepted by water utilities. Often, researchers use simplified versions of systems with simulated water streams, making translation to real water sources uncertain.

But even when new systems are tested at the bench scale using actual source water, geographical and seasonal variations in water quality stretch testing and evaluation to months or years. Utilities often will not consider testing for a new process until successful operation is proven at another utility, and even then, in-house testing is necessary to determine operational protocols and effluent quality.

One way to accelerate implementation of novel technologies is to prioritize industry-university partnerships. These partnerships can be mutually beneficial, exposing university researchers to testing protocols, scalability, and cost barriers early in the research timeframe, while the utility or industrial partner gains important insight into a novel process using its own source water in testing much earlier in the process.

One promising initiative is the Leaders Innovation Forum for Technology (LIFT), undertaken by the Water Research Foundation and Water Environment Federation (a water industry association) to increase innovation by connecting universities and utilities for research, development, and demonstration of new technologies (Brown et al. 2019).

Useful partnerships have also developed organically when a utility taps faculty and students from local universities to help fill knowledge gaps in prospective new technologies. One such example is a longstanding partnership in Washington between the District of Columbia Water and Sewer Authority’s Blue Plains Advanced Wastewater Treatment Plant and several local universities: -Howard University, George Washington University, Virginia Tech, and the University of the District of Columbia. This partnership provides opportunities for graduate students to perform applied research onsite at the treatment plant while researchers at the utility and universities work collaboratively on the development and implementation of innovative technologies.

The water sector will benefit when more such partner-ships are developed and supported.

References

Brown M, Karimova F, Love N, Pagilla K, Bott C, He Z, Liner B, Merther S. 2019. University-utility partnerships: Best practices for water innovation and collaboration. Water Environment Research 92(3):314–19.

Burek P, Satoh Y, Fischer G, Kahil MT, Scherzer A, Tramberend S, Nava LF, Wada Y, Eisner S, Flörke M, and 4 others. 2016. Water Futures and Solution: Fast Track Initiative (Final Report, WP-16-006). Laxenburg, Austria: International Institute for Applied Systems Analysis.

Dongare PD, Alabastri A, Pedersen S, Zodrow KR, Hogan NJ, Neumann O, Wu J, Wang T, Deshmukh A, Elimelech M, Li Q. 2017. Nanophotonics-enabled solar membrane distillation for off-grid water purification. Proceedings, National Academy of Sciences 114(27):6936–41.

Gleick P. 2003. Global freshwater resources: Soft-path solutions for the 21st century. Science 302(5650):1524–28.

Igbinigun E, Fennell Y, Malaisamy R, Jones KL, Morris V. 2016. Graphene oxide functionalized polyethersulfone membrane to reduce organic fouling. Journal of Membrane Science 514:518–26.

Kiparsky M, Sedlak D, Thompson B, Truffer B. 2013. The innovation deficit in urban water: The need for an inte-grated perspective on institutions, organizations, and technology. Environmental Engineering Science 30(8):395–408.

Maxwell S. 2013. Water Market Review: Growing Awareness, Growing Risks. Boulder: TechKNOWLEDGEy Strategic Group.

Sadeghi I, Kronenberg J, Asatekin A. 2018. Selective transport through membranes with charged nanochannels formed by scalable self-assembly of random copolymer micelles. ACS Nano 12(1):95–108.

WHO/UNICEF [World Health Organization/United Nations Children’s Fund]. 2017. Progress on Drinking Water, Sanitation and Hygiene: 2017 Update and SDG Baselines. Geneva.

About the Author:Kimberly Jones is associate dean for research and graduate education in the College of Engineering and Architecture and chair of the Department of Civil and Environmental Engineering at Howard University.