An outcome of all this warming is that humidity is decreasing and evaporation of water from all surfaces increasing. The additional moisture in the atmosphere is linked to an increase of weather-related catastrophes: drought, wildfires, hurricanes, tornados, floods, etc. No wildfire in recorded history had burned from one side of the Sierra Nevada Mountain range to the other; in 2021, it happened twice.⁶

These increasing temperatures and evaporation rates, coupled with a rapidly growing population, have exacerbated freshwater scarcity for agricultural, commercial, industrial and residential applications.

The World Resources Institute projects a 56% shortfall of fresh water within a decade. And in areas such as the western U.S., prone to water shortages, droughts are expected to get much worse. Experts predict that they will be the worst in recorded history, and last for 100 years. To describe these megadroughts, some are using the term “Aridification.”

Looking forward, we should expect severely limited freshwater supplies in the face of increasing demand.

Industrial wastewater    

In developed countries, industry can consume as much as 60% of available freshwater supplies, and most is simply discharged after use. Accordingly, industrial wastewater is significantly underutilized, and yet represents an immense source of both reusable water and possibly valuable components (recoverable “contaminants” in the wastewater). In industry, fresh water is used for many purposes, such as rinsing, cleaning, product manufacturing and other processes. This article addresses methods to treat the wastewater to generate a quality of water that can be reused within the facility and also processes to recover valuable components from the removed contaminants.

In September 2020, a survey of companies with annual revenues exceeding $1 billion revealed that most plan to “better manage” their water within the next two years.¹⁴ Some have gone so far as to declare that they will become “water positive,” meaning that more high-quality water will leave the facility than enters it. This includes water conservation and leakage prevention as well as wastewater recovery and reuse.

Resource recovery opportunities    

Treating wastewater provides an opportunity for more than just recovering water. While these streams must be treated to remove contaminants that could affect human and environmental health, some may provide valuable, recoverable assets, such as nutrients, high value metals and embedded energy. In certain situations, it may be possible to recover thermal and pumping energy. Additionally, valuable components can be "fractionated" and isolated for reuse, while also recovering the treated water. This concept of “resource recovery” (specifically, multi-resource co-recovery, as wastewater treatment is reimagined as water resource recovery) is detailed in a number of articles, including “There’s Gold in Them Thar Waters”⁷ and “We Should Expect More out of our Sewage Sludge.”⁸

The chart below illustrates several classifications of water-borne contaminants and examples of recoverable products.