Breaking the Ozone code (Part 1)

Water disinfection is currently a key area explored extensively as water quality and safety face ever stricter regulations and more utilities in the region are turning to advanced solutions.

While there is always the traditional gas chlorination method, De Nora Water Technologies (DNWT) has been developing alternative solutions such as on-site chlorine generation, ozone and chlorine dioxide, in combination with filtration technologies. Utilities in countries like Myanmar, the Philippines and Singapore now supply safe and clean water more sustainably because of DNWT’s technologies.

Water & Wastewater Asia had the pleasure to speak with Marwan Nesicolaci, Sr. Vice President of Global Sales & Operations Asia, Water Technologies Business, who shared valuable insights on key issues in water disinfection – the serious threat of micropollutants, DNWT’s latest innovation in ozone disinfection and its regional plans for the near future.

Marwan Nesicolaci, Sr. Vice President of Global Sales & Operations Asia, Water Technologies Business, De Nora Water Technologies (Photo credit: De Nora)

De Nora’s acquisition of Ozono Elettronica Internazionale (OEI) in 2015 has allowed the company to introduce CAPITAL CONTROLS® Ozone Generatorsto the market. Ozone, a natural element, has proven to be a formidable force in the water disinfection market as it is more effective than chlorine in destroying viruses and bacteria and creates no harmful residue. It can also be used in combination with existing disinfection infrastructure for difficult-to-treat applications, in advanced oxidation processes and sludge reduction.

Q: For how long has DNWT been developing alternative solutions such as on-site chlorine generation, ozone and filtration?

MN: Ozone, in other words, is technology. We are in a very unique position because we have a very broad product line that includes multiple disinfection technologies and one of the products we did not have was the ozone technology, so De Nora’s acquisition of OEI in 2015 allowed us to introduce the ozone technology into our disinfection product line. OEI was an Italian company with a strong presence in the international market.

The ozone product that we have is one that has over 3000 installations in Europe, especially in Italy over the last 30 years, so it is not a new technology but an improved one. Being that it was a small, Europe-based company, its primary market was in Europe. Through our presence and organisation in Asia, primarily in China, Japan and Singapore, we are making this product available by direct distribution through sales channels, and through our direct sales people in Asia Pacific, and not only to deliver the product but to also support it from the region as well.

Q: Municipalities nowadays are more open to explore alternative disinfection method besides the traditional gas chlorine, how do ozone disinfection solutions fare in the global market?

MN: The advantage De Nora has, is that we can provide the majority of disinfection technologies in the market now. We don’t try to convince clients that one solution is better than the other, rather we look at the issues they have and give them the right solution, which may involve one or multiple disinfection or filtration technologies.

Why? Because it depends on the type of water you are disinfecting and the budget availability of the user.

For reason of costs and ease of operation, chlorine gas disinfection is still very widely used in the public sector—it is very efficient and very inexpensive. But there are also municipalities which are looking for alternatives, such as Hong Kong. They have looked at all different technologies before going with on-site chlorine generation because it suited them best. That is looking at transportation, the quality of water, by-products, safety and such. It also depends on the chemical compositions in the waste water.

When water is disinfected with different technologies, there are different by-products that are formed, which is an important issue in municipalities now. Besides by-products, the other consideration is residuals of the disinfectant used. Ozone is one of the strongest oxidants, so if you want a high oxidant agent for disinfecting your water, there is nothing better than ozone. If the solution to a water issue requires no residual and very low or no by-products, then ozone is an ideal technology to use.

In many cases with ozone, clients buy smaller scale pilot system first because they want to see the effects of ozone on the particular water they have. Usually they will observe its performance for 60 to 90 days to see its effectiveness, check for by-products, etc.

Q: Where is ozone disinfection technologies in use now?

MN: It depends, every country has a different disinfection preference. In France, the municipalities prefer ozone as the method of disinfection for potable water. Historically, it is what they decided to go with. In India, the municipalities prefer gas chlorine and chlorine dioxide.

Other than looking at the type of water and the budget they have, sometimes it also depends on the availability of chemicals that are to be used by the chosen disinfection technologies.

In Italy, the availability of the sodium chlorite chemical as one of the raw materials to create chlorine dioxide is very prevalent in the province of Lombardia where it is produced, so the disinfection solutions adopted in Italy included the use of this chemical. The operational costs of chlorine dioxide technologies are inexpensive provided you have readily available raw materials, which are usually sodium chlorite and hydrochloric acid, among other chemicals. 

Japan uses ozone in various applications, some in the municipal sector but more on the industrial side. Ozone has been used quite effectively, primarily because the industrial sites have very difficult waste water and again you need a very powerful oxidant to oxidise the compounds in industrial waste water.

Ozone is also very commonly used in the food and beverage industry, usually to disinfect bottled water. Water treated with ozone doesn’t carry any aftertaste and it also has a short enough lifespan such that it evaporates by the time that you open the bottle of water, so you get no aftertaste but you have clean water. It is therefore the right technology for that application.

A lot of F&B companies in Asia are using this technology. Most Asian countries that produces bottled water in Asia use ozone.

Q: What are the latest innovations De Nora is looking at now?

MN: In recent years, we have been looking at different issues in water and looking at combining different technologies.

One of which is for the treatment of micropollutants. Micropollutants are not yet well-regulated globally, but it is an issue that is starting to gain more importance. Micropollutants come from one of the biggest industries – the pharmaceutical industry- where traces of pharmaceuticals can now be found in water bodies.

Our typical waste water treatment plants are not designed to remove these micropollutants, so when it comes to reusing the water, although it may meet general standards, these micropollutants in the water may lead to health issues, we aren’t even sure what they are today.

So we are looking at various solutions in how to resolve this issue of micropollutants and one very effective way, which we are piloting, is the combination of ozone and biologically aerated filtration (BAF). The combination of the two is an excellent and very powerful solution because the ozone technology can convert these compounds from non-biodegradable to biodegradable. Then you have to filter them out, this is where BAF is very effective in removing these compounds.

Again, it is a relatively new solution. A lot of studies and pilots are going into this. In Asia, we have the same issues and concerns, especially in Singapore. There is not a lot of regulation for now, but it is being looked at by various government, UK and the EU in general is currently the most advanced in this.

Q: What is the potential in this innovation?

MN: This particular solution will be piloted in Europe and the U.S. The potential is mainly in countries which have been looking at the issue for a few years. The US is one of the key countries looking at these issues and with a lot of potential, especially in states which are water stretched, like California and Florida, where water reuse is very important. UK is definitely one that we are looking at as well. Legislation with regards to micropollutants in municipal waste water is being looked into as well, a lot of studies are going on right now to understand the extent of the issue and what potential solutions are available. Switzerland is one of the countries at the forefront of this drive.

Q: What is the motivation behind such innovations? Is micropollutants such a huge threat?

MN: It is driven primarily by the need of supplying the population with the safest water possible. Water reuse is very important, but how do you regulate the water reuse for human consumption or for water reclamation? You have to look at a number of different issues, and some of which we don’t even know what they are today. But for now, micropollutants is one of main issues.

Also, as we start to reuse waste water, there is a need to understand all the compounds that are in it and the potential long-term effects on the population that you are delivering the water to, even it is just reused for reclamation purposes, such as addressing stale water intrusion in the aquifers. This is really the driver, and a lot of that need to be regulated by a combination of industry and regulators.

That is already happening in some countries. For example, in the US, both the regulators and the industry are trying to understand micropollutants and how to treat them and they have combined efforts to make this happen: funded workshops and programmes that share pilots to advance understanding. Eventually when regulation really do happen, they will be assured that these issues can be solved. Many a times, when there are yet to be regulations, there is no proven effective way of resolving the issue.

As with anything, the technology may be expensive, but there are drivers such as regulations and safety, and it is something you need to meet, whatever the solution.

Q: What is DNWT’s regional development plans?

MN: The target of our growth in Asia is primarily in Vietnam, Indonesia, Malaysia, Myanmar and Philippines, those are five countries for us that have a number of different drivers: economic growth and infrastructure growth, within the industry that we cater to – municipal, the energy (oil, gas, power) and petrochemical industries, which is a new industry that we are starting to enter.

We had always had some products in the petrochemical industry but we are trying to penetrate markets such as the hydrocarbon processing industry. We are targeting the hydrocarbon industry as there are many requirements for water treatment and our analysis has shown that a large part of our technologies portfolio offer solutions in the water aspect of that industry.

*This interview was first published in the July/August 2018 issue of Water & Wastewater Asia.