Environmental awareness is a global trend encompassing nearly every government
entity and private industry today. Discussions about the effects of climate
change and the resulting impact to our natural resources particularly focus
on the interconnected relationship between the water and energy sectors.
Building a sustainable future includes the promotion of an environment with clean air and clean water, the necessary infrastructure to support them and an energy use profile necessary to provide prosperity for current and future generations. Improving the energy efficiency and reducing the gas emissions from municipal water and wastewater treatment plant operations are increasingly viewed as valuable strategies in building a sustainable future.
A growing trend in the municipal water and wastewater markets has been the
evaluation and implementation of alternative treatment technologies. This evaluation
has focused on the review of direct capital and operating costs, as well as
quantitative and qualitative performance criteria impacting the true costs
of implementing such technologies. Examples of performance criteria include
safety, reliability and redundancy, aesthetics, water recovery, pre- and post-treatment
considerations and more. As utilities look to build a sustainable future and
are more conscious of the environmental impacts of their water and wastewater
treatment operations, criteria such as carbon footprint, CO2 emissions
and energy efficiency are becoming more important in the evaluation process.
On-site sodium hypochlorite generation
For more than ten years, on-site
sodium hypochlorite generation has been a proven, cost-effective, reliable
and safe alternative disinfection treatment method. The benefits of the on-site
generation process are well known: reduced operational costs; consistent solution
strength; on-demand production; non-hazardous byproduct; does not require the
same level of risk management planning as traditional disinfectants.
But now, a significant advancement -- an enhanced, proprietary electrode coating
-- enables the ClorTec® line of on-site sodium hypochlorite generation
systems to reduce customers’ carbon footprints and salt consumption by
as much as 20 percent. Salt consumption is reduced to as low as 2.5 lbs/lb
of chlorine (to 2.5 kg/kg of chlorine) and energy consumption is reduced to
as low as 2.0 kwh/lb of chlorine (to 4.4 kw/kg of chlorine).
The enhanced ClorTec systems produce a lower carbon footprint, increase efficiency
and result in significant operational savings. As disinfectant demand increases,
the increased efficiency provides even greater savings. The systems require
less salt, thus reducing salt levels in the produced water and the amount of
salt discharged to the overall environment. Since less salt is required, the
number of delivery trucks on the road can be reduced, resulting in lowering
of CO2 emissions. And fewer delivery trucks on the road reduces
the transportation industry’s dependence on foreign oil.
Capturing hydrogen for energy
On-site sodium hypochlorite
generation has made, and continues to make, a significant contribution to water
and wastewater disinfection systems around the world. But the byproduct of
the on-site generation process – hydrogen – may
itself someday prove its value as an energy source. According to the United
States Department of Energy’s 2002 “National Hydrogen Energy Roadmap,” hydrogen
holds the potential to provide a clean, reliable and affordable energy supply
that can enhance America’s economy, environment and security. The roadmap
notes that, “In the coming decades, the United States will need new energy
supplies and an upgraded energy infrastructure to meet growing demands for
electric power and transportation fuels. Hydrogen provides high efficiency,
can be produced from a variety of domestically available resources and offers
near-zero emissions of pollutants and greenhouse gases.”
Work is being undertaken with industry experts to evaluate the potential reuse
of hydrogen byproduct from large scale on-site generation processes for vehicle
fuel, heating fuel, electric power generation by hydrogen-fueled internal combustion
genset (a distributed generator system) or cogeneration from a hydrogen-fueled,
high-temperature fuel cell.
As the water and energy sectors seek to advance technologies that can positively
impact environmental sustainability, existing solutions may prove to have surprising
new applications. In the case of on-site sodium hypochlorite generation, its
benefits for water and wastewater disinfection may soon be joined by its potential
for helping to provide an environmentally friendly, renewable energy source.
For more information, e-mail info@severntrentservices.com.