High energy solution
TAMUS'S Electron Beam technology has many potential beneficial uses in the wastewater industry.
Earlier this year, Headworks BIO signed an option agreement with the Texas A&M University System (TAMUS) that enables it to negotiate an exclusive licence for TAMUS’s Electron Beam (E-Beam) technology for use in municipal wastewater treatment applications.
E-Beam processing or electronic irradiation is a process that involves using electrons, usually of high energy, to treat an object for a variety of purposes. Possible uses for electronic irradiation include sterilisation, disinfection, to cross-link polymers, and modify materials.
This process can break the DNA molecules in micro-organisms resulting in microbial death and rendering the product or sample sterile. E-Beam processing is currently in use commercially for the sterilisation of medical products, pasteurising food to protect against food-borne pathogens, developing aseptic packaging materials for foods, as well as in the disinfestation from grain, tobacco, and other unprocessed bulk crops.
To attain the global goal of an environmentally sustainable society in which organic material is successfully recycled back to arable land, it is crucial to develop effective procedures for the treatment of sewage sludge. The term sewage sludge or biosolids represents the insoluble residue produced during wastewater treatment and subsequent sludge stabilisation procedures, such as aerobic or anaerobic digestion.
To reduce the potential for adverse environmental and human impacts, it is critical that novel approaches be investigated so that municipal biosolids and effluent can be disinfected and stabilised to reduce the pathogen loads, reduce the levels of estrogenic compounds, and make the material suitable for land-application. Disinfection of effluent and removal of estrogenic compounds allows for a variety of high value applications of the effluent.
The issue of health risks from land-applied biosolids and wastewater microbes is a key concern to municipal wastewater utilities. However, it should not be overlooked that biosolids are significant pools of energy substrates and nutrients as well.
Headworks’ hypothesis is that wastewater treatment plants of today have to become Sustainable Resource Recovery Facilities of the future. There is a compelling need to exploit different technologies to extract as much of the energy and nutrients as possible from different waste streams.
"With the E-Beam, in one process you reduce a digestion from hazardous levels to benign levels"
The National Center for Electron Beam Research (NCEBR) at Texas A&M University in College Station, Texas, is researching ways to harness E-Beam and X-ray technologies to treat municipal drinking water, wastewater, and industrial waste streams. It is hypothesised that high energy (10 MeV) Electron Beam technology has the potential to add value in the following applications:
• Disinfecting sludges to Class A standards
• Stabilisation of sludges
• Disinfecting wastewater effluents
• Reducing estrogenic activity in sludges and effluent
• Potentially reducing digester residence time and enhancing methane production
E-Beam disinfection or sterilisation has advantages over traditional methods that are currently in use. The process is a quick switch on-switch off technology that does not use any radioactive materials, does not produce any radioactive waste, and is probably one of the most environmentally sustainable technologies since it uses commercial electricity. This technology can be used to treat material that is flowing through pipes or on conveyor belts.
Breaking down organic molecules such as benzene, an industrial solvent used in the production of drugs, plastics, and rubber and which is a known carcinogen, can require several treatments, known as digestions.
By contrast, when you treat wastewater with an Electron Beam, the organics are oxidised and the microbial pathogens are inactivated. With the Electron Beam treatment, in one process you reduce a digestion from hazardous levels to trace levels that are benign. Pathogen-free sewage sludge is a valuable commodity. In the US, about 40% of sludge is applied to land as fertiliser, so any technology that inactivates bacteria, viruses, and parasites is of high value.
One conventional treatment technique, called sludge wasting, creates a microorganism brew in which bacteria grow and feed on one another.
Then a centrifuge squeezes water out of the sludge, leaving a paste that can be heat-sterilised to produce dry particles for fertiliser. Studies performed at Texas A&M University demonstrate that E-Beam technology can be used on sludges at varying doses to obtain sludge that meet Class A specifications.
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