Courtesy of Bord na Mona Environmental Products US Inc.
Oct. 31, 2008
With 36 states expected to experience moderate to extreme water shortages by the year 2013, the time has come for the United States to rethink its approach to the treatment, storage and reuse of water on a residential, industrial, and municipal level, according to Bord na Móna Environmental Products U.S. Inc. President Shane Keaney.
“The aging United States water treatment infrastructure now requires significant investment just as water shortages are increasing in magnitude throughout the south and west of the country,” Keaney said today. “Many of our current municipal wastewater treatment systems are large centralized works that often waste the water resource rather than reuse it and consume too much energy to move wastewater from the source to the treatment plant.”
“As this existing infrastructure deteriorates, our water shortages are increasing at an alarming rate,” he asserted. “According to the Palmer Hydrological Drought Index, 38% of the United States was experiencing moderate to severe levels of drought by the end of 2007. By 2013 water shortages are anticipated in 36 states.”
The combination of these developments, coupled with the advent of a new generation of proven, cost effective water reuse treatment solutions, presents the nation with the opportunity to take a radical new approach to the issue, Keaney explained. “We believe that the time has come to reduce investment in centralized systems and start investing in a 21st Century treatment infrastructure that is developed on sustainable water reuse technologies.”
There has been a historic concern about the robustness, cost and operational effectiveness of residential and decentralized systems, creating the need for treatment solutions that deliver reduced complexity, and provide affordability for the customer. Flat plate membrane systems exhibit many of these characteristics and a new generation of membranes designed specifically for the decentralized market are becoming available that improve air scouring efficiency eliminating the chemical dosing and back pulsing equipment and allowing periods between recovery cleans in excess of 12 months. As the greatest portion of operating costs for decentralized systems is often associated with the provision of manpower, unattended operation through simplicity in design, and introduction of remote monitoring technology will be critical to making these systems affordable. “Many decentralized water reuse plants are located within existing neighborhoods where space is limited and aesthetics and odor control are critical. This has led to a growing demand for membrane bioreactors installed within buildings with ventilation and odor control provided,” he asserted. “While at the residential level solutions are being developed to “save every drop of water” by combining membrane wastewater recycling with rainwater harvesting.”
Another conservation development that is going to become an important part of future treatment solutions is water mining, Keaney said. “With water mining wastewater is extracted from the pipes that lead into centralized wastewater facilities. Once extracted, the water is treated locally for industrial and water recharge applications. All communities stand to gain from water mining but drought-challenged areas can greatly benefit by incorporating water mining into any new system design.”
Factors that will be taken into account to assess the sustainability of water infrastructure include :
1. the quantities of concrete & steel used, promoting small footprint technologies
2. the power consumption
3. the use of recycled materials
4. the requirement for and quantity of chemicals used, which are recognized as having a significant carbon & environmental footprint
In addition to the odor concerns Keaney pointed to the fact that Volatile Organic Compounds (VOCs) are now been recognized as a leading cause of both air pollution and health issues. Innovative biofiltration solutions now exist to address both threats. In addition states such as California have recognized the need to reduce chemical usage, highlighting the unsustainable approach of traditional chemical scrubbers.
The good thing about the challenges we face, Keaney stressed, is that the technology now exists to make viable, sustainable treatment solutions a very practical, cost-effective reality. “According to Keaney, ‘new technologies such as moving bed bioreators and submerged aerated filters are starting to replace the traditional activated sludge systems due to their smaller footprints, use of recycled plastics for media, and lower power consumption. Odor control biofilters that use media such as oyster shells do not need any chemical addition and are low headloss reducing the energy demand for fans are being promoted. For residential wastewater systems, media filters using textiles, recycled plastics and peat, which require minimal maintenance, do not require mechanical blowers and feature very low power consumption, are now being utilized in more and more installations.”
These new technologies are also being increasingly used in areas where tightening regulation requires the reduction of nitrogen and phosphorus in wastewater discharges to prevent the contamination of bodies of fresh water and pollution of water supplies.
The entire range of Bord na Móna water, wastewater, and odor control system solutions will soon be showcased at a new million dollar Bord na Móna Innovation Center being built adjacent to the Greensboro, North Carolina municipal wastewater treatment facility. “This Center will showcase our full range of technologies, allow for third-party verification, and enable increased research, development and optimization of new water reuse, wastewater, and odor technologies.”