New Advanced Water Reclamation Demonstration Plant Commissioned

Padre Dam Municipal Water District (USA) opened its Advanced Water Purification Demonstration Facility in late April of this year. The demonstration facility will use advanced water purification technologies to purify and test approximately 100,000 gallons of recycled water each day.

The facility was designed to deal with California’s severe drought conditions by developing a new local water supply. The full scale system would have the potential to provide a water source that is up to 20 percent of Padre Dam’s current drinking water supply.

The new process has four treatment steps – free chlorine disinfection, membrane filtration, reverse osmosis and advanced oxidation (ultra violet light and hydrogen peroxide). Advanced oxidation is capable of killing difficult to eradicate pathogens and removing micro pollutants other processes can not treat.

If successful, the treated water would be injected into the ground water basin to be withdrawn at a later time for treatment prior to distribution as drinking water. Additionally, Padre Dam will study the possibility of expanding Padre Dam’s proposed Advanced Water Purification Project to accommodate and treat wastewater from the other agencies’ service areas in order to provide additional water supplies. This expanded program could produce up to 10 million gallons of water per day.


Advanced Oxidation Facilitates Industrial Wastewater Reuse

Advanced wastewater treatment technologies can allow industrial enterprises to reuse water and thus decrease industries use of fresh water resources. Currently, these processes are expensive and are probably only suitable for developed economies. This is compatible with the nature of industrial water use which increases with per capita GDP.

Industries consuming the most water include textile, chemistry, paper and food industries. Studies done in the EU and the US have shown that advanced water treatment technologies can increase reuse of water, thereby reducing the demand on freshwater resources.

Advanced oxidation process (AOP) using ozone and hydrogen peroxide combined with various membrane separation technologies can make industrial wastewater suitable for reuse. AOP is able to break down organic materials that are not readily biodegradable, sometimes referred to as refractory, making them amenable to biological treatment processes. The ozone reacts with the peroxide to form hydroxyl radicals. The hydroxyl radicals are a non specific oxidizing agent that breaks down organic materials into smaller molecules. Water quality is improved in other ways, for example reduction in odor and color.

The produced water can be used for different applications within the industrial complex such as cooling water make-up, water for back washing filters and other applications where the water quality is not as important. Even if the water is discharged, it is much less toxic and the environment can absorb it much more easily.

A further advantage of AOP, unlike membrane processes, is that there is no stream of concentrated waste formed. The entire water stream is treated to an higher level of quality. This offers the potential of zero liquid emissions.

Water reuse with AOP is a proven alternative, but its application is strongly dependent on economics. These technologies are both capital and energy intensive. the application of AOP will thus depend on water availability, quality and price, as well as regulatory requirements for zero emissions of polluted water.

Given the increasing limits on water resources and increasing regulations, AOP technologies such as ozone peroxide are likely to find ever increasing application.


San Diego Moves Forward with IPR Demonstration Employing Advanced Oxidation

San Diego City Council members approved a Water Purification Demonstration project using a indirect potable reuse (IPR) program.

Implementation of an IPR would provide a significant new local water supply, while reducing the amount of primary effluent discharged to the ocean, helping the City avoid a $1.5 billion upgrade of the Point Loma Wastewater Treatment Plant.

IPR projects take tertiary treated municipal wastewater through an extensive filtration process using membranes followed by some form of advanced oxidation. Advanced oxidation methods used include ozone/peroxide and UV/peroxide. These methods can remove micro pollutants and kill any remaining micro organisms. The water is then normally injected into a well field for later recovery for drinking water use. A direct potable reuse project (DPR) would take the water directly to a drinking water treatment plant.

A two-year study of a 1 MGD (3,785 m3/d) demonstration project at the North City Water Reclamation Facility (WRF) demonstrated the robustness of the multi-barrier MF/RO and advanced oxidation arrangement to produce better-than-potable-quality water from tertiary effluent. The California Department of Public Health (CDPH) gave conditional approval to the proposed IPR concept.


Boulder Installs UV Wastewater Disinfection

Boulder’s wastewater treatment plant started up a new $3 million UV disinfection system purify the city’s wastewater. Flows are 12.5 million gallons per day of wastewater. Costs are comparable to the previously used chlorine gas/sulfur dioxide chemicals previously employed, however the safety and environmental aspects of UV are dramtically better than the chemicals.

The UV does not create disinfection byproducts that may be harmful to aquatic life, reduces the carbon footprint of the plant by elimianting the need to transport the chemicals and improves the safety and security of the facility related to the storage and handling of the chlorine and sulfur dioxide. A failure of one of he 2,000 pound storage cylinders could result in an extensive evacuation of people for a couple of miles around the plant. In total, the plant stored upwards of six tons of the toxic chemicals on site at any given time. Hazard response teams were on call in case of any kind of accident.

UV wastewater disinfection has become an important technology. Most new facilities constructed have dopted UV. Different kinds of UV systems exist. Boulder uses a low-pressure, high-output UV system.

Other technologies such as advanced oxidation or combining UV with ozone water treatment or hydrogen peroxide can potentially remove trace organics or small carbon products. Boulder has not considered those technologies yet, but is leaving its options open. UV, ozone and other related technologies are changing the way water and wastewater are treated. These technologies reduce the formation of dangerous byproducts, improve safety and security at the facilities and provide better treatment.


Muttenz Switzerland to Treat Groundwater with Advanced Oxidation

The groundwater in Muttenz, Switzerland will be purified using a combination of advanced oxidation, adsorption and ultrafiltration. The water is subject to organic trace substances and occasionally impacted by Rhine filtrate.

Difficult to treat compounds will be oxidized using ozone and hydrogen peroxide. The ozone and peroxide react to form hydroxyl radicals that are fast reacting and non specific oxidants that will break down virtually all organic molecules. Technologies like ozone peroxide combination that produce these radicals are geneerally referred to as advanced oxidation processes.
In the next phase powdered active carbon (PAC) will absorb the residual substances and finally ultrafiltration will be employed to filter out the activated carbon in combination with the adsorbed contaminants. Such a combination ensures that micro-pollutants, which are otherwise difficult to degrade, can be safely removed or reduced. This fact has already been confirmed by the operational results from the pilot plant at the location.

Muttenz is the first plant in Switzerland to be equipped with this particular process technology. The new drinking water treatment plant will produce about 5 MGD of ground water and is expected to start operation in December 2014.


Korean Drinking Water Plant Purchases First Advanced Oxidation Treatment Process

A municipal drinking water system in a new high-tech industrial zone in South Korea has contracted for an ultraviolet (UV) advanced oxidation process (AOP) treatment technology. This is the firts time such a technology will be applied in Korea for drinking water.

The water treatment facility will treat more than 26 million gallons per day, and will be the first step in the development of the new $3 billion Sihwa Multi-Tech Valley project, a government-backed regional industrial development initiative being implemented by the K-Water municipality. The new hub for the enterprise is due to be completed by 2016, and aims to attract high-tech industries across the IT, chemicals and R&D sectors.

UV reactors and AOP technology will be used in the existing plant, Siheung wastewater treatment plant, for the removal of micro pollutants and disifection.

AOP is being used around the world to address problems associated with micro pollutants such as pesticides, personal care products and pharmaceuticals that find their way into drinking water sources.


Water Reuse Requires Multiple Barrier Approach

In previous posts we have talked about reuse of wastewater for drinking purposes including the feelings of Americans towards the use of wastewater for their water supply. In reality, many American’s already use wastewater as their drinking water source. If your drinking water plant is down stream of another cities wastewater plant, you are in effect drinking their wastewater. This does not include the impact of farm run off and run off from animal waste. The standards for treating water downstream of the wastewater plant is not nearly as high as for direct reuse, but that is what is happening ecluding teh dilution effect.

One aspect of the issue of water reuse that we have not covered is the anlytical aspects for evaluating water quality in these situations. Obviously, utilities must be aware of the different contaminants present in the water and have clearly defined public health goals before deploying technologies to treat the water. Some of the contaminants associated with pharmaceutical or personal care producsts are in extrmely low concnetrations, e.g. nano gram per liter quantities. So, sophisticated analytical techniques are required to measure these contaminants before and after treatment. Additional analytical techniques are required for measuring the advanced oxidants that are sometimes applied in these applications.

In terms of treatment, the complexity of the chemistry of water contaminants at different stages of the water cycle results in no single technology being able to remove all the contaminants. Thus, a multiple barrier system is needed to ensure their reduction and removal. This is the same approach promoted by the US EPA to balance treatment of difficult to remove micro organisms while minimizing disinfection by products.

Advanced oxidation technologies effectively remove many pharmaceutical and personal care products and disinfect the water. Ultraviolet (UV) light can be effective in destroying some contaminants, such as N-nitrosodimethylamine, as well as killing a most micro organisms. Reverse osmosis can remove most contaminants, but creates a concentrated waste stream that contains the contaminants. Ozone, another strong oxidant, can also be used before or after water enters the reverse-osmosis membranes to remove contaminants.

Water reuse treatment often includes the use of UV or oxidation and membrane-based technologies as part of a multibarrier treatment scheme. Alternative schemes such as ozone and granular activated carbon filters are being explored to disinfect the water and remove contaminants, residual odours, discolouration and by-products created by other treatment processes.

Water reuse is slowly becoming a reality in the US out of necessity due to decling water source quality and increasingly stringent regulations. Ozone and advanced oxidation have an important role to play in this regard along with other advanced water treatment technlogies.


Ozone and Advanced Oxidation Find Opportunities in Fracking Water Treatment

Fracking has created a large application for various water treatment technologies such as ozone and advanced oxidation processes. Both processes have been used to either breakdown organic contaminants in the water, remove Fe and other minerals or for disinfection of the water prior to injection. An advantage of ozone based processes is that the ozone is made from air and after reaction breaks down into oxygen, leaving no dangerous byproducts and simplifying logistics.

The stock market is starting to take notice. Environmental services stock Heckmann Corporation soared nearly 38% on the NYSE after announcing the acquisition of privately held Power Fuels for $125 million in cash and 95 million shares of stocks. Both companies are involved in fracking water treatment. Ecosphere, which uses ozone based processes, is also a public company drawing a lot of attention.

As the use of fracking continues to expand, ozone and advanced oxidation should continue to see increased usage.


Ontario Studies Advanced Oxidation for Wastewater Treatment

Ontario is investing in innovative solutions to help protect Great Lakes water quality. The Keswick Water Pollution Control Plant is testing an advanced oxidation process to reduce the amount of phosphorus and micro pollutants such as pharmaceuticals and personal care products entering Lake Simcoe.

Advanced oxidation processes have been demonstrated to remove pharmaceutical and personal care products from water and wastewater and several municipalities have initiated treatment systems based on this technology already.
The Keswick project is part of Showcasing Water Innovation, a program that supports projects that demonstrate innovative and cost effective approaches to improve drinking water, wastewater treatment, and storm water systems that can be used by communities across the province.

The program is helping communities find innovative wastewater treatment solutions to keep Great Lakes healthy. 80 percent of Ontarians get their drinking water from the Great Lakes. Water and wastewater is the largest sub-sector of Ontario’s environment industry employing 22,000 people and generating and $1.8 billion in sales.


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.