sign in sign up
<<
Home , Reclaimed water

SUMMARY

Publication number: TM-18-15

Pollution Prevention (P2): Closed Loop Systems and Other Options for While 71% of Earth’s surface is covered in , only about three percent of that water is —including glaciers and caps. Arizona, a desert state, receives a small amount of per year, requiring supplemental from several nearby reservoirs. Arizona's rapidly growing of roughly 6.5 million people uses about 2.3 trillion gallons of water per year.1 Wastewater can be used to extend the lifespan of utilized water and reduce consumption at the source. Closed loop systems technologies can be beneficial to any industry and business such as reusing wastewater generated in the manufacturing industry for cooling and heating purposes. Depending on the type of wastewater reused, this may require an initial (or continuing investment) and a knowledge of the quality of water reused. This resource summary offers general information on closed loop systems.

What Is a Closed Loop System? Without the ability to recycle wastewater, Stages of Treatment and the ISS would have to ferry approximately A closed loop system is a process for 5,000 gallons of water per year to support of Contaminants wastewater or other input reuse where all basic functions.6 and Particulates water or other inputs used are indefinitely A public rest stop in Dunnigan, CA runs a recycled. The system is made possible via closed loop water system which The National Academies of Science, chemical additives and/or electrical uses recycled plastics as the ideal Engineering and Medicine describe the currents to neutralize and remove all materials. So far, the system has utilized contaminants and particulates from 400 cubic feet of 100% recycled plastics.7 stages of the closed loop water 5 wastewater repeatedly, which returns the Applications and Benefits of treatment process as follows: water to its original usable state.2 Recycled Wastewater Primary -- removal of portion of The purpose of closed loop technology is suspended solids and organic matter The U.S. Environmental Protection Agency to maximize the use of natural resources Secondary -- biological treatment; (EPA) outlines several ways in which and other materials. In this manner, all reclaimed water can be reused removes biodegradable organic matter resources from beginning to end are (some processes may be closed loop)4: and solids. This step usually incorporates utilized and repurposed, thereby disinfection of water. reducing the use of new materials and • Industrial processes creating an overall reduction in source • Pre-washing tools/equipment Advanced5 -- nutrient removal, filtration, .3 • Re-use of water in heating/cooling complete disinfection, final removal systems of organic matter and solids as well as Closed Loop System Examples • Replenishing a basin (also dissolved solids and trace constituents. Closed-loop systems can be incorporated known as a , in many industries, activities and wherein groundwater supplies are Throughout the process of these stages, scenarios. For example, the Sebatier supplemented with wastewater, which all extracted contaminants and has been extensively treated to meet System on NASA’s International Space particulates are examined for and surpass standards)5 Station (ISS) incorporates a closed loop repurposing. Oxidized metals, for system that reacts byproducts carbon The following are benefits of water reuse: example, are added to and dioxide and hydrogen to produce up to 530 gallons of water per year. • Conserving potable water and costs recovered oils are recycled. • Mitigating discharge of wastewater into ground water and surface by re- circulating utilized water

This resource summary was created by the Arizona Department of Environmental Quality’s Pollution Prevention Program using funds from a P2 Grant provided by the U.S. Environmental Protection Agency. RESOURCE SUMMARY

Closed Loop Methodologies There are various technologies through which the closed loop system for wastewater reuse can be implemented:2 • Electrocoagulation (EC): utilizes to propel chemical reactions in a solution, thereby removing 99.9% contaminants • Biocides: disinfectant used to eradicate pathogenic (disease- causing) fungus and mold • Polishing filter, such as or membrane reactors (semi- permeable to pore-sized membranes in conjunction with biological treatment process)

Closed-loop technology enables NASA Doug Wheelock works to install the Sabatier System to extract water out of the ISS recycling of not only wastewater, but atmosphere. Photo credit: NASA also chemicals and other process input materials. Recycling these can reduce References the need for additional amounts at the 1Arizona Department of . Water Your Facts. source. These source reduction opportunities include: 2Els, Patricia. WaterWorld.com. Embracing Closed-Loop Technology for Recycling and • Freshwater requirement reduction Reuse.

• Reduction in chemical use via solvent 3 reuse Fedkin, Mark. Technologies for Systems. Recycling: Open-Loop vs. • Hazardous waste generation Closed-Loop Thinking. reduction through re-use of the 4 material instead of classifying it as a EPA. Potable Water Reuse and Drinking Water hazardous waste4 5National Research Council. Water Reuse: Potential for Expanding the Nation's Supply Compliance and Exclusions through Reuse of Municipal Wastewater. The exemption allowed by closed-loop 6NASA. The Sebatier System: Producing Water on the Space Station. recycling, found in 40 CFR 261.4(a)(8), enables waste generators to qualify 7Waymouth, Belinda. Huffington Post Blog. Poop + Plastic = Good News for H2O their wastewater reuse as an exclusion Parched . to hazardous waste generation.8 Secondary materials, or byproducts, that 8EPA. Criteria for the Definition of Solid Waste and Solid and Hazardous Waste are reclaimed and returned to their original generation processes are Exclusions. excluded from the total amount of hazardous waste generation accounted For translations or other communications aids, please email the Title VI Coordinator at [email protected]. Para for and thereby incentivize generators traducciones u otras ayudas de comunicación, envíe un correo electrónico al Coordinador del Título VI al to focus on wastewater recycling processes. [email protected]. Though RCRA enables exclusions for amount of hazardous waste generated via closed loop recycling, companies must ensure compliance with all regulations regarding exclusions, cited in 40 CFR 261.4(a)(8) (i-iv).

This resource summary was created by the Arizona Department of Environmental Quality’s Pollution Prevention Program using funds from a P2 Grant provided by the U.S. Environmental Protection Agency.