Ozone Water Treatment a Major Part of North Central Texas Drinking Water Systems

As a follower of this blog will be aware, the majority of surface water treatment systems in the Dallas-Fort Worth Metroplex and North Texas have added ozone to their treatment process. Currently, more than 130,000 lbs/day of ozone capacity is installed to treat up to 2.5 billion gallons per day (BGD) of drinking water in North Texas with the City of Dallas accounting for 40% of this capacity.

These utilities experience many of the multiple benefits ozone brings to water treatment including seasonal taste and odor control, reduced DBP levels, enhanced filtration with lower turbidity, chemical dosing and solids handling in addition to superior disinfection.

Mazzei® mass transfer systems have played an important role in putting Ozone to Work© in new, expanded or updated North Texas water treatment plants in the last 7 years. The 5 most recent ozone installation chose patented Mazzei venture injectors, basin mixing nozzle manifolds, pipeline flash reactors or full GDT transfer and degassing systems to add up to 52,000 lbs/day of ozone to nearly 900 MGD of drinking water. Benefits of the Mazzei systems included mass transfer efficiencies ranging from 90 to 98%, small footprint, large turn down ratio, easy installation and low maintenance.

Spartan employs Mazzei products in its ozone water treatment installations and considers Mazzei to be a important partner/supplier.

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Orange County Opens New Ozone Water Treatment Plant

Orange County has opened its new Southern Regional water supply facility, which can produce up to 30 million gallons of drinking water a day. The new facility pumps water from 6 wells driven deep into the lower Floridan Aquifer. The water’s cleaned with ozone and piped out to 21 thousand homes and businesses in the region. At the moment it produces about 12 million gallons a day, but the plant can pump more water as more houses are built.

Ozone water treatment is growing technology for drinking water since it provides superior disinfection performance while minimizing byproducts found in the water. The use of ozone is often combined with more traditional disinfectants such as chlorine for the distribution system to provide multiple barriers of protection for public health.

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Australian Floods May Have Been Prevented by Water Reuse Schemes

The long Australian drought increase interest in Australia for people to talk seriously about recycling our sewage to use as drinking water. It is possible that if recycling schemes had been in place, the massive floods that followed last year might not have happened.

There are two kinds of recycled water: ‘Indirect potable reuse’ or IPR uses advanced water treatment processes such as reverse osmosis and advanced oxidation, before discharging the recycled water back into a river, reservoir, or underground prior to re-harvesting it, retreating it and reusing it. ‘Direct potable reuse’or DPR would do away with the return to the environment and the water would be pumped directly back into the city’s water supply system.

By the worst stages of the drought around 2007, it had become clear that some of Australia’s largest cities would need to adopt varying approaches to IPR in order to make full use of available water supplies. Major IPR schemes have since been partially developed in Queensland and Western Australia.

The Western Corridor Recycled Water Project (WCRWP) was developed during 2007-2010 partially as a means to supplement drinking water supplies in Lake Wivenhoe, South East Queensland. This is the primary source of drinking water supply for Brisbane and much of the surrounding area. The WCRWP uses effluent from six wastewater treatment plants, which is then subjected to advanced water treatment at three new plants at Bundamba, Luggage Point and Gibson Island.

Some of this advanced-treated water is now used for industrial purposes, but the idea of drinking it has been postponed until storage supplies drop to below 40 per cent of capacity.

That public’s negative response to the idea of drinking treated effluent is one of the reasons why DPR is not being pushed. But the floods may change the attitude about recycling. Like many reservoirs, Lake Wivenhoe has two conflicting roles. On one hand, it must provide security of drinking water supply by storing as much water as possible. One the other, it must protect Brisbane from otherwise inevitable regular flooding by maintaining as much empty space as possible. To achieve these twin objectives, the reservoir is divided into two distinct components. The bottom 1,165 billion liters is kept as full as possible for drinking water supply and the top 1,450 billion liters is maintained empty for flood control.

When operating at full capacity, the WCRWP can produce around 35 per cent of the total water consumption of Brisbane and surrounding areas. If this water was used directly as part of Brisbane’s water supply, Lake Wivenhoe could be relied upon for 35 per cent less water supply. This means that the same security of water supply could be maintained while dropping the full supply capacity of Wivenhoe by 35 per cent and thereby freeing additional space for flood mitigation. The flood mitigation capacity would be increased by around 425 billion liters, which is an increase of around 30 per cent.

In terms of water storage capacity, this new-found 425 billion liters of flood mitigation space is the same as immediately constructing a new equivalent sized reservoir, without the cost of construction and without having to relocate a single home or farm. In addition to completely avoiding the environmental impacts of new dams, it would enable less water to be captured by the dam enhancing natural flow regimes in the Brisbane River. To put this extra storage capacity into some context, a new 425 billion liter reservoir would be the fourth largest reservoir to supply drinking water to a major city in Australia.

Using the existing infrastructure of the WCRWP, water would be available immediately and there would be negligible construction costs. But most importantly, the freed-up storage space will also be immediately available to help capture and control major flooding events when they occur. With careful management, this additional storage capacity would have been sufficient to capture and contain the entire peak flow into Wivenhoe Dam that occurred between 9th and 13th January 2011. There would have been no flood in Brisbane.

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Ozone Seen as a Potential Treatment for Endocrine Disruptors in Water

The European Environment Agency, EEA, has warned that products containing endocrine disrupting chemicals should be treated with caution until their true effects are better known. A few such chemicals have already been banned, but many are still in widespread use.

Recent studies have shown that endocrine disruption has serious effects on wildlife. Impact on people has not been demonstrated yet, but agencies like EEA and the EPA are looking into the issue.

Chemicals of interest include: phthalates, often found in pesticides; bisphenol A and other PCBs, used to make plastics; parabens, found increasingly in sunscreen; and the chemicals used in contraceptive pills. The concern is that not a single compound is dangerous, but taken as a whole the danger is not fully understood. This includes the potential interactions between teh various compounds. This makes the problem difficult to study.

Endocrine disrupting chemicals (EDCs) interfere with the body’s hormone systems, which is why some of the most common are those found in the contraceptive pill.

The EEA study is the first to take a comprehensive review of the evidence gathered over the past 15 years, and it concludes that there is cause for concern. According to the study, EDCs have been found to be connected to a higher incidence of breast cancer, and an earlier onset of puberty, as well as to male fertility problems including lower semen quality.

Ways of dealing with EDC’s included stricter treatment of sewage, such as installing sand filtration, membrane filtration and using ozone to purify water.

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