Experience & Innovation

We can solve your ozone needs


Since 2008

Guardian Research & Development Laboratory (GRDL) was established in 2008 to address the specialized needs of highly complex ozone and advanced oxidation process (AOP) chemistry. Our state of the art facility is equipped with multiple ozone generator systems, ozone injection systems, reactor vessels, and analytical equipment necessary to evaluate a wide range of water, wastewater, and gas-­phase ozone applications. Overall, the GRDL lab is equipped to address nearly any foreseeable sample or testing application by utilizing cutting-edge treatment technology and over 30 years of collective experience in the ozone industry.


GRDL offers a full suite of water and gas phase testing for a wide range of ozone-based applications. Laboratory bench-scale and/or pilot-scale testing is crucial in evaluating the performance of ozone-based processes and provides critical information for full-scale system design.

Due to the scalability of ozone-based testing, many customers also find that laboratory bench-scale testing is extremely valuable in evaluating or troubleshooting performance in existing full-scale systems. GRDLs extensive experience and knowledgeable staff offer data and solutions for your most challenging ozone applications.

Applications We Test

  • Drinking Water Disinfection
  • Color Removal
  • Trace Organics Removal
  • Specialty Materials Testing
  • Municipal Drinking Water
  • Contact Sanitation
  • Organic Chemical Oxidation
  • Trace Organics & Pharmaceuticals
  • Transition Metal Oxidation & Precipitation

Industries We Serve

  • Municipal Drinking Water
  • Specialty Materials
  • Food Manufacturing
  • Seafood Harvesting & Packaging
  • Produce Growing/Packing
  • Textile Finishing
  • Environmental Remediation
  • Cold Storage
  • Commercial Laundry
  • Bottling & Packaging
  • Industrial & Municipal Wastewater
  • Aquaculture
  • Aquariums & Zoos


GRDL is equipped to perform a range of aqueous and/or gas phase ozone testing
on water or product samples of almost any size and for almost any application.


GRDL is equipped to evaluate ozone / AOP process reactions for an extremely broad range of water samples. Typically, most testing is done on sample volumes of 1 to 4 liters. However, the lab is also fully equipped to accommodate pilot testing of up to 3,000 gallons of artificially simulated water samples for specialty applications. All water testing begins with initial sample characterization tests to approximate the ozone demand of the sample and assist in determining the appropriate ozone dosing technique for the testing process. The bench-scale tests can all be performed with a jacketed reactor allowing us to control the sample temperature during testing to within ±0.2°C.

GRDL utilizes two different ozone dosing techniques for ozone demand testing, liquid ozone dosing or ozone gas injection. The appropriate technique is chosen based on the results of the initial characterization tests. If the ozone demand of the sample is estimated to be between 0.5 – 10 mg/L, the liquid ozone injection method will be employed. For this dosing method, a stock dissolved ozone solution with an ozone concentration of greater than 100 mg/L is created. The concentrated stock solution is then analytically transferred and injected into the representative sample. After dosing, the residual ozone concentration is monitored over time to calculate the ozone half-life and decay rate.

If the initial characterization tests determine the ozone demand of the sample to be greater than 10 mg/L, the lab will use a gaseous ozone injection technique. For this method, a representative sample will be dosed with 10-14%wt ozone gas using a full suite of precision monitoring equipment. This equipment includes but is not limited to the following: NIST calibrated mass flow meters and ozone analyzers; pH, temperature, ORP, and dissolved ozone probes; and GRDLs proprietary PLC-based testing system that continuously analyzes and records the data from all of the monitoring equipment.

Upon completion of the ozone demand testing, the treated samples are characterized again to quantify the changes to the specified target compounds. Our most common target compounds are total/dissolved organic carbon (TOC/DOC), color, iron, manganese, bromide/bromate, and phenols. We are also equipped to do ozone disinfection testing for heterotrophic plate count (HPC), E. coli, enterococci, fecal and total coliforms. Once the characterization has been completed, our scientists will analyze and interpret all of the data and compile it into a report with recommendations for your ozone project.


GRDL is one of the only laboratory facilities in the US equipped to conduct and evaluate gas and/or vapor phase testing of ozone or AOP applications. Gas and vapor phase testing is performed in a specially developed atmospheric chamber to ensure accurate and scalable results. The GRDL facility is also equipped with a state-of-the-art complement of analytical instrumentation for ozone, biological assay testing, and atmospheric monitoring in order to address almost any foreseeable need.


Beyond the testing services listed, GRDL is able to accommodate a broad range of specialized ozone / AOP testing needs. Our scientists are experts in the cutting-edge methods of advanced oxidation treatment techniques such as: ozone and hydrogen peroxide (peroxone), UV and hydrogen peroxide, UV and ozone, solid catalysts and electrochemical oxidation. We are happy to develop a detailed testing plan for your most demanding application. In the past we have designed specialty systems to assess or test material compatibility with ozone, textile processing applications, cleaning efficacy, and contact sanitation. Please contact us for more details.


Many large-scale ozone projects require a field pilot test to validate system performance and design prior to full-scale implementation. GRDL is equipped with pilot-scale ozone process equipment to accommodate flows from 1-100 gpm and ozone production from 10 g/hr to well over 32 lb/d. Pilot testing programs are custom configured to each client’s specific treatment objectives and site conditions to ensure scalable results. Testing equipment is available on a first-come-first-served basis and leased based on the duration of the testing protocol. Please inquire for equipment availability and further details.



Due to customer requests for the ability to measure dissolved ozone concentrations above 2 mg/L, GRDL has developed a high level ozone (HLO) test kit.

The kit comes complete with everything necessary to test dissolved ozone concentrations from 0.5 mg/L to 15 mg/L and is calibrated at Guardian’s Research and Development Lab based on the Indigo Colorimetric Method as outlined in Standard Methods 4500-O3.

The reliable ozone concentration readings are obtained from a HACH digital colorimeter that is custom programmed for each kit by a GRDL chemist. Every kit contains all of the necessary equipment for testing and detailed instructions on how to properly collect and test your sample.


Time, heat, and light exposure cause the indigo in the PITS solution to break down. Since the HLO Kits are programmed to measure the direct reaction of residual ozone with the indigo, errors can arise from the natural indigo degradation. When planning to make critical dissolved ozone measurements using your HLO Kit, check the expiration date on your bottle of PITS solution. If it’s expired, it’s time to order a new bottle to get the most accurate readings!

Have any questions? Inquire about our products or services by contacting us!


Color Reduction in RO Concentrate
Water Online article and Case Study on the installation of a Pinnacle Ozone system for color reduction of RO concentrate at a WTP. The system started out with an ozone demand test at GRDL, proceeded to an on-site pilot test, and then was completed in the fall of 2014 with the full-system installation.
Managing Bromate Formation

Water Online article about the growing bromate concerns in water treatment and what can be done to mitigate the problem.


Ozone Demand Testing

Water Online article about the importance of understanding your facility’s ozone demand profile prior to designing an ozone injection system. Having this knowledge beforehand can save thousands of dollars in engineering and project costs which is why we always suggest lab-scale ozone demand testing when considering ozone for your treatment needs.

Ozone for Wastewater Reuse

Water Online article about using ozone systems for wastewater reuse. With the drought conditions in the Western US, every drop of water counts and reusing wastewater is a critical piece of the water conservation puzzle. This article offers insights to help when considering ozone for your application.


Ozone for Disinfection

Water Online article about using ozone for water disinfection. This article explains why and how ozone can be used for your disinfection purposes.

Ozone for Disinfection – Part 2

Water Online article about using ozone for water disinfection. This article explains why and how ozone can be used for your disinfection purposes.

Ozone Disinfection Success

Water Online article about the most important factors to consider when using ozone for water disinfection.


Chain of Custody Form

Ozone Demand & Decay Sampling Protocol

HLO Kit Brochure

Guardian Research & Development Lab Brochure


GRDLs staff has over 30 years of experience in the evaluation and analytical methods for ozone and AOP reactions in both gas and water phase. Our staff is highly experienced in the specialized methods necessary for control and analysis of ozone-based reactions. We take great pride in working with each individual client to fully establish and achieve individual treatment goals for each project.

Thoram Charanda

Thoram serves as the Director of R&D for GMI and Pinnacle. In 1990, after completing a chemistry degree from the University of Florida, he took over the newly formed chemistry department for life support at The Living Seas in EPCOT. He gained extensive experience in ozone chemistry and disinfection applications while implementing the technology for the treatment of animal habitats across Walt Disney World property. Now, over 25+ years later, he’s built an extensive knowledge base of water and wastewater treatment options that allow him to develop treatment schemes and new devices that can be used in the ozone treatment process.

Thoram Charanda, R&D Director

Jessica Pedisich

Jessica serves as the Research Chemist for GRDL. After graduating with a chemistry degree from Mount Vernon Nazarene University in Ohio, she moved to Florida and began working in the water chemistry department at Walt Disney World. She joined the GRDL team in 2011 and has since taken on a majority of the lab-scale ozone testing and daily operations.

Jessica Pedisich, Research Chemist

Jackie Keys

Jackie serves as the Office Manager for GRDL. She graduated from the University of Central Florida with an emphasis in science as well as business. GRDL was the perfect match for her to unify these two interests when she joined the team in 2013.

Jackie Keys, Office Manager

Sasha Namundi

Sasha serves as the Special Projects Assistant for GRDL. She brought her 26 years of building code enforcement with her when joining Thoram for the construction of the lab in 2008. Once construction was complete, she took on the role of Office Manager, using her talents to get the lab operating smoothly. Since changing roles in 2013, she is still providing support to the lab for special projects requiring her expertise.

Sasha Namundi, Special Projects


2750 Dillard Road, Suite 12 Eustis, FL 32726

1+ 352-483-3333


3 + 10 =


We get a lot of questions from our clients. Here are a few that are asked most frequently. If your question isn’t answered here, feel free to contact us by phone or e-mail. We are happy to address any concerns you may have!

What size ozone generator do I need?

When an interested client contacts us, this is often the first question we’re asked. From our 30+ years of experience, we’ve found time and again that the best way to answer this question is with a lab-scale ozone demand and decay study using a representative sample taken from the source.

Lab-scale ozone demand testing ensures that the system will be properly sized from the beginning of the injection system design process. It eliminates any surprise issues that may arrive from theoretical sizing based strictly off of test data that may not show the full ozone demand picture. With our extensive demand testing background, we can ensure the system that’s installed will meet your needs.

Do you offer small-scale on-site ozone injection test systems?

Some of our clients find it critical to get a small-scale ozone injection system on-site to test with their source water prior to purchasing a full-size ozone system. Our pilot systems can be rented for testing either after a lab-scale test has been done or in lieu of lab-scale testing. These systems provide real-time ozone injection data which can be beneficial for a variety of situations.

The most common issue these systems help us to accommodate is fluctuating source water chemistry. These fluctuations typically lead to changes in ozone demand which may not be represented with a one-time sampling event that can be tested in the lab.

With the use of ORP and dissolved ozone probes, the ozone dose can be modified to satisfy the fluctuations in ozone demand. The ability to do this provides our engineers and clients with an accurate forecast of the necessary ozone system size.

What lab-scale testing capabilities do you have?

Our lab is capable of satisfying a multitude of test conditions. We have various jacketed reactors on hand that allow us to meet and maintain specific testing temperatures during ozone studies. This has proven to be especially critical for warm water applications where ozone survivability is greatly reduced, often necessitating higher concentration ozone dosing capabilities.

We can also perform lab-scale advanced oxidation process (AOP) testing. With automated dosing pumps and residual ozone probes, we can mimic a PID hydrogen peroxide dosing process (peroxone) in lab-scale so you know exactly what to expect with regards to ozone and peroxide demand. This process is made possible with our proprietary PLC data logging system that allows us to track test parameters as frequently as every second. Using this system, we can track ORP, temperature, residual ozone, ozone dose, mass flow, mass transfer efficiency, and, if applicable, hydrogen peroxide dosing data. All of this information gives a full picture of how our ozone systems can be used to treat your water needs.

Some of our Specialty testing has included:

  1. Gaseous ozone disinfection of food stuffs
  2. Textile bleaching with gaseous and dissolved ozone
  3. Dissolved ozone for agricultural irrigation
  4. Ozonation of stored agricultural products for pest management
  5. Dissolved ozone exposure of materials used in drinking water applications
  6. Mass transfer efficiency testing of specialty ozone devices
  7. Dissolved ozone for control of invasive aquatic species