San Diego Uses Advanced Oxidation to Recycle Wastewater

In summer 2011, the City of San Diego opened the Advanced Water Purification (AWP) Facility, a small-scale, state-of-the-art facility that purifies one MGD of recycled water. The facility is one component of the City’s Water Purification Demonstration Project that is examining the safety and cost of purifying recycled water. San Diego is examining water purification as a means to develop a locally controlled, supplemental water supply. San Diego’s semi-arid region is at the end of pipelines that bring imported water from hundreds of miles away. The City needs to develop local, reliable water sources to lessen its dependence on expensive and limited imported water supplies.

All wastewater in San Diego undergoes treatment to remove harmful contaminants, making it safe enough to be discharged into the ocean. Some wastewater is diverted to the City’s recycled water facilities, where it is further treated and then used for irrigation and industrial purposes. A portion of the recycled water produced at the North City Water Reclamation Plant is sent to the AWP Facility.

To become purified water, the recycled water undergoes a multi-barrier purification process, which includes membrane filtration, reverse osmosis, and advanced oxidation with ultraviolet disinfection and high-strength hydrogen peroxide. The multi-barrier approach of consecutive treatment steps removes or destroys all unwanted materials in the water and produces one of the purest supplies of water available anywhere. The same water purification process is already used around the world.

Visitors are encouraged to tour the City of San Diego’s AWP Facility.

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Ozone Biofiltration Enhances Drinking Water Treatment

Biological aerated filters (BAF) use submerged granular media to support biological growth and act as filtration medium, eliminating the need for clarifiers. If aerated, the filter can be used for carbon removal and nitrification. In an unaerated mode and in the presence of sufficient carbon source, this technology provides denitrification. BAF can be installed in separate stages for carbon removal, nitrification, and denitrification.

The first large-scale installation with a capacity of 14 mgd has been operating in Roanoke, VA, for two years, and similar size plants in Minnesota are starting up. Two large plants with peak flows close to 100 mgd are now under construction in Binghamton and Syracuse, NY, corresponding to hundreds of installations with different BAF systems in the UK, German-speaking countries, France, Scandinavia, and Japan.

Biologically active filtration is also applied in drinking water to reduce the biodegradable matter which might lead to regrowth of bacteria in distribution systems using ozone to enhance pollutant bioavailability and supply oxygen, downstream contactors of activated carbon or anthracite provide growth surfaces for biomass.

In contact times of 5 to 10 minutes, a significant amount of biodegradable matter can be removed, lowering the necessary disinfection dosage and reducing the formation of halogenated byproducts. The world’s largest plant with ozone/biofiltration is currently being completed at Southern Nevada Water Authority’s Alfred Merrit Smith water treatment plant in Las Vegas, with a daily flow of up to 600 mgd from Lake Mead.

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The Global Market for Ozone Technology Growing at Nearly 7% per Year

BCC Research has recently completed a technology market research report that provides an in-depth analysis of the global market for ozone technology across a range of applications. Key findings in the study are:

1. The global market for ozone technology is expected to grow to $838 million in 2016, a compound annual growth rate (CAGR) of 6.7% for the period. It reached $557 million in 2010 and $606 million in 2011.
2. The ozone water/wastewater applications segment of the market reached $426 million in 2010 and $460.5 million in 2011. It is expected to grow to $634 million for a CAGR of 6.6% between 2011 and 2016.
3. The ozone air and gas treatment segment reached $131 million in 2010 and $145.5 million in 2011. It is expected to grow to $204 million for a CAGR of 7.0% between 2011 and 2016.

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New Environmental Remediation Study Highlights the Application of Ozone Water Treatment

A new study by Global Industry Analysts indicates that environmental remediation is a global multi-billion dollar industry. Environment conservation and protection of human health from exposure to contaminated soil, surface water, and groundwater is important for governments around the world.

Groundwater contamination is especially important as it causes a major impact on supply of potable water in Europe, Asia and Latin America. It is estimated that about a third of the world population could witness water shortages, with likelihood that this situation would emerge in China, India, Pakistan and Middle East, while sub-Saharan Africa and parts of Asia would be the most affected. This is expected to drive the global groundwater remediation market. The US, Germany and Japan are in their fourth stage of development, making efforts to minimize waste management with emphasis placed on recycling.

The developed countries control 80% of the total environmental market, and are expected to record the highest growth. The environmental remediation market has emerged as a critical global issue. While conventional technologies are widely used to cleanup industrially contaminated sites, the use of new technologies show increasing promise. Ozone oxidation, an age-old technology used for the treatment of water, is finding new application for environmental remediation purposes.

The research report titled “Environmental Remediation: A Global Outlook” by Global Industry Analysts, Inc., offers an aerial view of the global environmental remediation industry, identifies major market challenges, and growth drivers.

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Amsterdam Upgrades WTP

Waternet has completed an efficiency upgrade project at a large water treatment works serving Amsterdam. The Waternet facility at Vogelenzang has a daily water treatment capacity of 48 MGD, using a regime comprising pre-screening, carbon filtration, ozone injection and sand filtration.

Waternet covers the entire water cycle, from the treatment of waste water and provision of drinking water to cleaning and maintaining levels of surface water. These services are performed on behalf of the Regional Public Water Authority – Amstel, Gooi and Vecht – and the City of Amsterdam.

Amsterdam was one of the first cities to adopt the use of ozone for disinfection over a century ago.

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Ozone Can Reduce Chemical Use in Citrus Storage and Distribution

Economic losses caused by post harvest diseases are an important problem in citrus plants. Most spoilage in oranges in storage and distribution is caused by penicillium digitatum. Currently this is controlled by the application of synthetic chemical fungicides. These compounds have environmental impact and their use may be reduced in the future by regulation.

Juice producing companies requires significant consumption of water and chemicals (detergents & disinfectants) for cleaning and disinfection of facilities, leading to a high volume of waste water.

AINIA technology center, Spain, has been investigating the development of cleaner post-harvest techniques applied to the citrus industry since 2010. This research has focused on three interrelated areas: hygiene equipment, product conservation and water treatment.

Laboratory and pilot work that has been completed concludes that the technical feasibility of developing systems for post-harvest treatment based on the use of ozone and ultraviolet light, is as effective as conventional systems,
and reduces the use of fungicides. Advanced oxidation of water discharged will regenerate the water that was used in treatments for possible reuse. Ozonated water used for cleaning juice tanks is as effective as the use of chemical disinfectants, but using a lower consumption of disinfectant and water.

Ozone is a powerful oxidant with a broad-spectrum bactericidal effect which does not generate chemical waste since it degrades rapidly to give oxygen, and ultraviolet light (UV) is a germicide that has no residual effect nor secondary.

Thus the use of advanced oxidation, has a high potential to become a useful tool for the citrus industry, mainly for its environmental benefits compared to traditional chemical fungicides used in post-harvest treatments or traditional disinfectants used in cleaning facilities.

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