Template Assisted Crystallization
Learning Objectives - After this course, you should be able to:
- Define a sustainable approach to water quality management using a template assisted crystallization (TAC) water conditioner.
- Discuss the environmental problems of water softeners, particularly the issues of using salt as a regenerating agent and the water that is discharged as a result of the regenerating cycle.
- Explain the detrimental and beneficial mineral components of water from both natural and treated water sources that can reduce energy efficiency and durability of plumbing fixtures and mechanical equipment.
- Integrate the components of an environmentally beneficial water system from water source to water waste to improve community water quality.
Water quality and the preservation of water resources are among the top reasons that designers become environmentalists. Professionals design to reduce, recycle and reuse water. They know that drinking water is a nonrenewable resource and water use impacts many aspects of building design, including energy consumption. Most designers already know that they can reduce water by using low-flow fixtures. Some are experimenting with gray water reuse and recycling within a building as well as for irrigation. A select few are beginning to understand the impact of source water, with its increasingly complex mix of minerals, contaminants and pollutants, on building systems.
Buildings are part of a natural hydrologic cycle. The flow of water through the built environment can greatly influence water quality and harm plumbing and heating systems. Designing for zero waste, zero energy, gold, platinum, zirconium rating systems and beyond, architects and engineers have focused a lot of attention on using nature as a guide for environmental design. What if nature needs nurturing?
Water contains common elements, among which are ions of calcium, magnesium, potassium and sodium. The problem with water is that high concentrations of calcium and magnesium contained in water molecules can cause scale to form on pipes and water heating equipment. Scale increases maintenance and causes premature mechanical failures resulting in as much as a 24 percent loss in energy efficiency in water heaters.1 The earliest method of water conditioning used ion exchange or softening as a means to control scale. However, these systems require regeneration cycles that backwashes salt brine as wastewater, causing an environmental problem for natural water systems. In parts of California, Michigan and other states, policy regulations that protect the water supply include the ban of water softeners that use salt to regenerate. These policies mean that new forms of water treatment needed to be more environmentally sensitive, friendlier to the environment and free of chemicals, salt and waste discharge.
Photo courtesy of Mark Chalom and Betty Tsosie
The Sleeping Rainbow Ranch Environmental Research Station is designed to be off the grid and conserve water. Template assisted crystallization water conditioning provided the solution to a complex requirement for energy-conserving, non-polluting water treatment.