Superfund Research Program
Development of a High Performance Bioprocess for Eliminating 1,4-Dioxane in Water
Project Leader: Joseph Salanitro
Grant Number: R44ES022123
Funding Period: Phase II: December 2013 – November 2016
Across the United States, water suppliers and managers are finding dangerous levels of 1,4-dioxane in water. This compound has been used for decades in a wide range of applications including as (1) a solvent in paints, varnishes, and prints; (2) treatment agent in artificial leather; (3) ingredient in pesticides and fumigants; (4) purifying agent in pharmaceuticals; and (5) solvent in resins, oils, plastics, adhesives, waxes, and cement.
1,4-dioxane is a probable human carcinogen at extremely low levels in water (parts-per-billion). It is highly soluble and thus travels extensively in water. Most importantly, few conventional water treatment technologies can remove 1,4-dioxane from water. There are only two current routes of eliminating 1,4-dioxane in water: UV or hydrogen peroxide coupled with ozone oxidation (i.e. advanced oxidation), and biological degradation. The energy and chemical costs of UV and chemical oxidation processes are often prohibitively high. There is also a significant risk of producing harmful by-products (such as carcinogenic bromate) and these technologies have limited applicability in certain circumstances.
Biological degradation also suffers from a number of drawbacks, including process stability, the need to induce degradation, limited performance, clogging, performance sensitivity, and the production of sludge or secondary waste streams. If these problems can be overcome, however, biological treatment offers a promising method of completely degrading 1,4-dioxane into harmless products, ensuring the integrity of the environment and protecting public health.
This Phase II project is based on successful Phase I results showing the feasibility of a new biological approach for 1,4-dioxane degradation that does not require pre-induction of the bacteria and can be applied using a new high performance bioprocess. The prototype developed in the Phase I work is being scaled and piloted at an actual contaminated site. The pilot is seeking to establish performance and operational parameters of the new technology, and to evaluate long-term and sustainable operation.
The research team is demonstrating and fully characterizing a first-of-its-kind high performance bioprocess for eliminating 1,4-dioxane in water resources. The technology's intended value proposition includes simple operation, rapid and effective degradation, wide applicability to a range of water sources, reliable performance, and lower overall costs compared to existing methods, especially chemical oxidation. Most importantly, the research is intended to provide a valuable tool for protecting and remediating drinking water supplies, thus safeguarding public safety and environmental sustainability.