Tokyo Treats Drinking Water with Ozone Biofiltration to Ultra High Quality

Not surprisingly, Tokyo has high quality water available from every faucet in the city. Japan is known for cleanliness and technology, and they combine these passions to treat their drinking water in their capital city.

There are many people who don’t like drinking from the tap and are instead willing to pay for bottles of water. The reality is that many drinking water plants produce water that is equal to or superior to bottled water. This is the case in Tokyo.

The basic quality of Tokyo drinking water is protected by 51 strict quality standards set by the Ministry of Health, Labor, and Welfare, including checks for toxicity and harmful contaminants, along with tests to ensure a palatable tint, clarity, and smell. Japan’s regulations for public water supplies are more stringent than those governing bottled spring water. What takes Tokyo’s water a step higher, though, is the metropolitan waterworks’ strict treatment regimen that includes roughly 200 parameters for safety and quality.

Five treatment plants run by the Tokyo Waterworks supply the city. The Misono plant is one of the five and has a daily treatment capacity of 300,000 cubic meters (about 80 MGD) and utilizes conventional treatment along ozone and biological activated carbon. This additional step removes virtually all remaining contaminants from the water.

Ozone is a strong oxidizing agent that reacts with various contaminants, including carcinogenic compounds, along with microorganisms such as bacteria and protozoa, eliminating potential health risks and improving the taste and odor.

In the second step of the process, water flows from the ozone contact chamber to the bio filtration ponds containing different grades of biological activated carbon. In addition to filtering out organic contaminants, much like a home water purifier, the microporous carbon also supports microorganisms that break down impurities and other byproducts of ozone treatment. If left behind, these contaminants can degrade the taste and smell of water.

The quality of source water determines the level of water treatment. Tokyo currently gets 80% of its water from the Tonegawa and Arakawa Rivers, drawing the remaining 20% from the Tamagawa River. The Tamagawa is pure enough that it only needs standard treatment to make it drinkable. Tonegawa and Arakawa Rivers require the advanced treatment explained above.

In the US and Canada many large drinking water plants have adopted the ozone biofiltration treatment process. In fact, in the US over 1.6 billion gallons of water a day are treated with ozone. Many of these plants have held contests where customer try to determine which is better in a blind taste test, tap water or bottled water. In many of the cities using advanced ozone water treatment, tap water wins.

Share

Ozone Drinking Water Treatment for Algae Related Issues

Algae in lakes and reservoirs can create issues for drinking water plants including toxins, bad taste and unpleasant odors in the water. While there are a number of treatment methods used to deal with this problem, ozone treatment of the water has emerged as a proven and cost effective method.

Depending on where and how the ozone is applied to the process, the ozone can serve two purposes: primary disinfection and removal of algae related compounds that pose health or aesthetic risks to the drinking water plants customers.

The city of Oregon in Ohio was concerned about algae related issues from their intake in Lake Erie due to cyanobacteria that can produce microcystin, a toxin. Toledo had experienced a severe issue with this toxin that resulted in a 2014 temporary ban on the use of water from their drinking water plant. This cause Oregon to look for solutions before they experienced a similar problem.

In Oregon’s process, water from lake Erie will be treated with ozone and then go through biological filtration. The approach will remove algae-related toxins. The process works because ozone breaks down the toxins into molecules that are quickly digested by the biology living in the filter.

The process was first tested at the pilot scale for several months to prove that it worked well. The full scale system is expected to be in operation by the algae season of 2017. Other advantages include reduced use of chlorine, improved disinfection and reduced disinfection byproducts. Ozone also eliminates trace organic compounds.

The project is expected to cost $14 million, with funds mainly coming from the Ohio Environmental Protection Agency’s Water Supply Resolving Loan Account. Oregon’s water rates will increase about $2 to $3 more a month for the improved quality and safety.

Share

Ohio Teen Dies from Infection at Water Park

CNN reported on July 3rd that an Ohio teen died due to infection by the amoeba Naegleria fowleri. He was exposed to the pathogen at the U.S. National Whitewater Center. According to the Centers for Disease Control and Prevention the infection was probably caused by the failure of the water sanitation system. All samples taken from the whitewater area of the park tested positive for the organism.

CDC believes that the amoeba was able to grow to high concentrations because of the amount of dirt and debris in the water, which turned the water “turbid” or murky and interfered with the effectiveness of the sanitation process. The sanitation process used both UV light and chlorine. Both would be adversely effected by high levels of turbidity and suspended solids.

It’s one of only three such systems in the United States that are not required to be regularly tested for pathogens. According to local health officials, that’s because it’s viewed as more of a river, even though the park is made of concrete channels that recirculate 12 million gallons of water from the city’s municipal water system.

The article goes on to state that there will be “challenging discussions” with experts to determine the best way to deal with the situation, including how to remediate the existing facility. I think this part should have gone without saying.

Being involved in the supply of equipment for sanitation of water, this tragedy brings home the diligence those of us in this industry must bring to our jobs. It also means educating our clients that instrumentation and testing are an important part of any water treatment process, especially where human health is at stake. It was convenient to say that this park was just like a river and thus did not require the type of controls that a normal water park would employ. That is the easy way out. It leaves public health officials, engineers and owners off the hook.

So, when you are working on a water project that involves human exposure to water, take the time to explain to the client, if they have not already considered it, to make sure they put in place the proper instrumentation and testing protocols. In this case, even a simple on line UVT monitor would have alerted operators to the failure of the UV system and perhaps prompted testing for pathogens.

Share

Ozone Considered for Improving Water Quality in Tyler Texas

The City of Tyler has released the results of an independent review of its water treatment process conducted by Enprotec/Hibbs & Todd, Inc. The study looked at the causes and possible remedies for high levels of haloacetic acids in the water. Haloacetic acids are a disinfection byproducts (DBP) which are regulated by the US EPA. They are formed when organic compounds in raw water react with chlorine to form chlorinated organic compounds such as haloacetic acids and trihalomethanes. In October of 2015 the city had received notification of high haloacetic acid levels in its drinking water.

The study recommended some operational changes to reduce the haloacetic acid levels, but some of the issues are due to the age of the water plant where the acid levels are the highest. The facility was constructed in 1950s before the onset of increased regulations on water quality. A newer facility uses ozone as a pre-treatment. The study recommends utilizing the ozone at the older water treatment plant, thereby reducing the amount of byproducts created by chlorine.

Ozone has been used extensively in the US and Europe to reduce the formation of chlorine based DBP’s.

Share

Emporium KS Upgrades Ozone Disinfection Drinking Water System

The Emporia City, KS Commission approved a request authorizing the Public Works Department to proceed with an Ozone Equipment purchase Wednesday afternoon during an active session. The current equipment at the Water Treatment Plant uses atmospheric air and bubble diffusers and was installed in 1995, with an expected life of 15 to 20 years. The Ozone equipment and process is the primary disinfection action at the Water Treatment Plant. The equipment, which is slated to be installed in 2016, with a project construction cost estimate of $2.6 million.

Ozone equipment installed 20 years ago was primary based on air feed as the source of oxygen for ozone generation. Using air as the feed gas results in lower concentration ozone of 1-3 percent ozone. Newer oxygen fed ozone generators produce ozone at 10 percent concentration. Higher concentration ozone dissolves more readily in water for more efficient use of the ozone produced.

There is also a reduction in the size of the generator to produce the same mass of ozone, normally indicated in pounds/day. The reduction in the nitrogen levels also minimizes damage tot he generator due to the formation of nitric acid.

As a result of these advantages newer ozone systems have shifted to some form of oxygen feed, either from liquid oxygen supplied by gas companies or made on site using oxygen concentrators. The latter take air and remove the nitrogen to get to oxygen levels of 93%.

The first ozone systems were installed 20-30 years ago and are now being upgraded as the one in Emporium is later next year.

Share

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.

Share

Brits Water Plant in South Africa Adds Ozone

According to Kormorant news papers the upgrading of the Brits Water Treatment Plant at a cost of R578 million could help alleviate the water problems the Madibeng Local Municipality. The upgrade will not only improve the capacity of water provision, but quality as well. As part of the project, the Ozone Purification System which could see the municipality receiving a Blue Drop status, will be installed. The Ozone Purification System is a system used to kill bacteria, i.e. disinfect water and is used by many municipalities throughout the world.

Share

Ozone Systems Market Expected to be $1.25 billion in 2020

A recent market study by Persistence Market Research suggests that global market for ozone technology market was $715 million in 2013 and is expected to grow to 1,242 million in 2020.

Ozone technology is used for a wide variety of applications, but primarily for water purification, disinfection and the removal of organic and inorganic contaminants. Ozone technology equipment has promising growth rate in the waste water treatment equipment, in municipalities, and other water treatment segment which include swimming pools and spas. This growth is attributed to the many benefits associated with the technology. High oxidation potential, quicker processing time compared to other traditional disinfection techniques, with no harmful by-product.

The increasing global health concerns due to surge in urbanization, increasing water contamination and increasing level of industrialization are driving the ozone technology market globally. The government expenditure on upgrading water infrastructure has increased in the past decades across all regions., Municipalities are upgrading from traditional chlorine-based disinfection to UV and ozone technology based disinfection which has boosted ozone technology market. There is also an interest for both municipalities and industry to remove organic contaminants from water, ozone and ozone based advanced oxidation processes have been found to be useful in this regard. Water treatment related regulations in some of the countries are also compelling water and waste water service establishments to modify their water treatment techniques to improve safety level of water.

Share

Celina, Ohio Deals with Algae Blooms Using Ozone and GAC

Recent news regarding the algae related water quality problems in Toledo have raised issues about the potential for algae blooms and the release of toxic chemicals from the algae elsewhere in the US and especially in Northwest Ohio.

Celina, another town in Ohio, uses Grand Lake as its water source, which has encountered problems with the algae blooms and the toxins they release since 2009. Celina, however, has updated treatment system to deal with these issues.

The city uses two methods of water treatment to make its water safe, ozone and granular activated carbon treatments. Ozone is a powerful oxidant and highly effective disinfectant. It is a technology that has been in continual commercial use for more than 100 years and has distinct properties that allow disinfection of even heavily compromised water streams.

The GAC treatment is an extremely versatile technology and in many cases has proved to be a cost effective option. GAC absorption is particularly effective in treating low concentration waste streams and in meeting stringent treatment levels. GAC is known to remove a wide variety of toxic organic compounds to non-detectable levels.
As with any water treatment technology, suitability on a specific application normally depends on costs as they relate to the amount of carbon consumed.

Share

North Texas Municipal Water District Begins Operating Nations Largest Ozone Drinking Water Facility

The North Texas Municipal Water District (NTMWD) began using ozone as the primary disinfectant at its Wylie Water Treatment Plants in 2014. As a result of the $123 million ozone project, a significant improvement in the taste and odor of the drinking water produced is expected. The NTMWD selected ozone in the treatment process because of changes in US Environmental Protection Agency’s Safe Drinking Water Act.

Now operating the nation’s largest water treatment facility using ozone, the NTMWD implemented extensive planning efforts, modifications, construction and project management at the four Wylie Water Treatment Plants. In addition to the Wylie location, the Bonham and Tawakoni Water Treatment Plants also produce ozonated water. Cumulatively, NTMWD has the capability to treat and deliver 806 million gallons per day of high- quality, safe drinking water to the region served.

Ozone is a good choice for municipal drinking water treatment because it offers multiple benefits to the plant operators. In the case of NTMWD, it allowed them to meet more stringent US EPA regulations for disinfecting drinking water while also improving the waters taste and odor profile. Using another primary disinfectant would have required a second process or chemical to deal with the taste and odor.

Share