Environmental biotechnologies can make water pollutants part of the path to mitigating climate change

Abstract

To slow and ultimately reverse global climate change, society needs to replace fossil sources of energy and chemicals with renewable forms. Environmental biotechnologies, which utilize microbial communities that can provide human society with sustainability services, can play key roles towards this goal in two ways that are the focus of this perspective. First, technologies that employ anaerobic microbial communities can produce renewable, carbon-neutral energy by transforming the energy contained in the organic matter in wastewaters to methane gas, hydrogen gas, or organic chemicals used in the chemical industry. High-strength organic wastewaters are common from many facets of our systems of food supply: e.g., animal farms, food processing, uneaten food, and biosolids from sewage treatment. While anaerobic digestion of sewage biosolids is a long-standing method for making renewable methane, new, more-advanced environmental biotechnologies are making energy-generating anaerobic treatment more reliable and cost-effective for treating the wide range of organics-bearing wastewaters and for producing output with greater economic benefit than methane. Second, photovoltaic, wind, battery, and catalytic technologies require large inputs of critical ninerals and materials: e.g., Rare Earth Elements, Platinum Groups Metals, gold, silver, lithium, copper, and nickel. Environmental biotechnologies can create new, renewable sources of the critical materials by recovering them from wastewaters from mining, ore-processing, refining, and recycling operations. When provided with hydrogen gas as an electron donor, anaerobic bacteria in biofilms carry out reduction reactions that lead to the formation of nanoparticles that are retained in the biofilm and can then be harvested to serve as feedstock for the photovoltaic, wind, battery, and catalytic technologies. This perspective describes both ways in which environmental biotechnologies will help society achieves it sustainability goals.

A paradox of accelerating change

“…Lane picks up on this theme, urging the UN Water Convention to "highlight the water-related actions with the largest impacts on reducing greenhouse gas emissions," from agriculture to wastewater treatment plants and wetland management [4]. In the same vein, Rittman argues that ameliorating water pollutants using environmental biotechnologies can mitigate climate change [5].…”