Drinking Water, Fully Characterized
MANTECH’s revolutionary peCOD Analyzer technology measures the chemical reactivity and associated oxidative changes in Natural Organic Matter (NOM). As a result it is more sensitive than Total Organic Carbon (TOC) and UV254 to changing NOM concentrations in source and treated drinking waters.
Follows ASTM International approved method D8084
Download PeCOD Pro™ Software for Benchtop L100
peCOD is the fastest available method for quantifying oxygen demand (OD), providing operators with real time data needed to make timely, impactful decisions that enhance environmental protection while generating substantial savings on chemical and energy use. It offers a low detection limit (< 1 mg/L) with results generated in less than 10 minutes.
peCOD offers a safe, fast and green chemistry method that can be used by anyone. This eliminates the need for trained analytical chemists on staff or an external lab facility
The core of the technology is the peCOD sensor, which consists of a UV-activated nanoparticle TiO2 (titanium dioxide) photocatalyst coupled to an external circuit. When a sample is introduced into the microcell containing the peCOD sensor, the TiO2 is irradiated by UV light, and a potential bias is applied. The UV light creates a photohole in the TiO2 sensor with a very high oxidizing power and organics in the cell are oxidized. peCOD is extremely accurate across a broad range of organics. The powerful oxidizing potential of UV-illuminated TiO2 ensures that virtually all species will be fully oxidized giving a true measure of OD.
The peCOD Analyzer is available in a variety of configurations that use the same innovative technology and method. peCOD combines robust performance and flexibility to suit the needs of your laboratory or process operations.
Models and Specifications
The peCOD Analyzer is available in laboratory, portable and online configurations that are highly customizable. The peCOD system can be configured to accommodate laboratory operations, automated sampling, or continuous process monitoring.
The Benchtop L100 peCOD Analyzer is MANTECH’s base model for use in municipal, government and academic lab settings.
- Small footprint (235 x 375 mm, 9.25 x 14.75 in)
- Lightweight (5 kg, 11 lb)
- MANTECH’s PeCOD Pro™ software adds automation and a sleek user interface
- Can be upgraded to Automated or Online systems
The world’s fastest method for oxygen demand (OD) analysis is also available in a portable field unit. Just add the battery and carrying case and OD can be measured in the field!
- Small footprint (508 x 355.6 x 609.6 mm, 20 x 14 x 24 in)
- Convenient case with wheels (weighs approximately 16 kg, 35 lb with analyzer & supplies)
- No sample digestion is required, making it a truly portable technique
- MANTECH’s PeCOD Pro™ software adds automation and a sleek user interface
The Automated L100 peCOD Analyzer provides unattended analysis for a large number of samples.
- Unattended, continuous analysis of 73 samples
- System is pre-calibrated before the start of each work day
- Additional parameters can be added on, including pH, EC, alkalinity, BOD and turbidity
- Save time and money through process optimization with real time OD results
- Option to add automated pH adjustment and dilutions
- Additional parameters can be added on, including pH, conductivity, alkalinity, and ammonia
Case Studies and Resources
Frequently Asked Questions
OD (Oxygen Demand) measures the chemical reactivity of organics by the demand for oxygen, as shown in the diagram below. It can be used as an additional tool in the characterization of NOM (Natural Organic Matter) to predict DBP (Disinfection by-product) formation. This metric also allows for rapid feedback and optimization of coagulation and disinfection dose requirements.
The PeCOD Analyzer performs advanced oxidation on a small volume of sample. As the reaction proceeds, electrical charge is generated proportional to the oxygen being consumed. The PeCOD analyzer captures this generated charge, plotting the output current from the reaction over time as shown below. The area under the curve generated by plotting current over time is proportional to the oxygen demand of the sample. A blank charge is also determined for each sample, and subtracted from the total charge to ensure accuracy.
View the detailed overview of PeCOD technology and calculations here.
Natural organic matter (NOM) is a critical target for drinking water treatment because it causes a negative effect on water quality by color, taste and odor, and can react with disinfectants to form disinfection by-products (DBP). There are several tools for measuring NOM in source and ground water that include total organic carbon (TOC), dissolved organic carbon (DOC), UV absorbance at 254 nm (UV254), specific UV absorbance (SUVA), and chemical oxygen demand (COD).
UV254 is a water quality test which uses ultraviolet light of 254nm wavelength to measure natural organic matter in water and wastewater.
THMs (trihalomethanes) are disinfection by-products (DBP’s) formed when residual chlorine reacts with elevated levels of naturally occurring organic matter found in water. THMs are present in most drinking water supplies and are dependent on several factors such as type of organic material present and chlorine dosage.
TOC (Total Organic Carbon) is the amount of carbon based organic contaminants in a water system. TOC does not identify each specific organic contaminant present, but rather an absolute quantity of all carbon-bearing molecules. In other words, TOC is a way to measure organic contaminants that may pose a threat to drinking water or wastewater systems.
A common benefit of peCOD implementation for this application is optimization of coagulant dosing.
The traditional method up to this point has been consistent dosing based on laboratory testing results (jar testing is a very common method of developing coagulant dosing requirements). They then increase their dosing for events that they know to cause NOM spikes. The problem is they often don’t know the extent of the NOM spikes, so they increase their dosing to what has been deemed as ‘enough’. More often than not this is over-dosing, not really causing downstream issues but incurring more cost than is needed for these events. However, when the extra dose is not enough and they under-dose, NOM gets through and reacts with the disinfection chemicals creating DBPs.
The missing ingredient is knowing when these NOM spikes occur, and to what extent. The events could be anything from seasonal variation based on climate to rapid spikes from storm events, but the benefit of knowing is the same. Plants that have enough funding to do so monitor UV and TOC online, however research has shown that this is not enough. peCOD is another piece of the NOM puzzle and is truly the more important measure when looking at how NOM will react and be affected by treatment. If you know the COD of the NOM coming in and can match it to known dosing requirements, you minimize the possibility of DBPs forming.
The speed and ease of use of the peCOD is also key here, you are placing this knowledge directly in the operators’ hands, rather than having it be a result they wait to get back from an external lab. When they can truly understand the technology and it’s value, it has a secondary effect of getting them more involved with optimizing the treatment processes. We see with numerous cases (mostly in WWTPs at this point) this occurring, where they get the peCOD for measuring one or two points then realizing the benefit it can have through monitoring their whole plant.
Samples must be filtered prior to peCOD analysis to ensure that no particulates greater than 50 micron (um) are primed into the peCOD. Particulates larger than 50um can cause clogging, which can lead to damage of the internal fluidics of the machine. To prevent clogging and ensure proper sample preparation, MANTECH has a Sample Filtering Guide for PeCOD Analysis.
For pulp and paper and wastewater applications, MANTECH recommends using a 35um polyethylene (PE) syringe filter. These filters can contribute trace amounts of organics, which are negligible for wastewater applications. For drinking and source water applications it’s important to use a filter that does not contribute organics to the filtered sample. One of MANTECH’s research partners has recommended a 0.45um polyethersulfone (PES) filter; however, other filter types may also be acceptable, if no organics are contributed by the filter. Since these applications traditionally see less particulates, having a smaller pore size filter hasn’t shown an impact on the peCOD results.
The PeCOD electrolyte solution is mainly composed of a low-concentration lithium nitrate solution, and has a shelf life of two years. The PeCOD calibrant and check standard solutions supplied by MANTECH are composed of sorbitol and have a shelf life of one year. These solutions contain a trade recipe preservative that allow for the longer shelf life, compared to solutions prepared manually. Calibrant and check standard solutions prepared manually, following the PeCOD Standard Recipe, can be used for up to two weeks.
View the PeCOD electrolyte SDS here.
View the PeCOD calibrant SDS here.
View the PeCOD check standard SDS here.
The primary driver of the peCOD method chemistry is advanced oxidation induced by photocatalysis with Titanium Dioxide (TiO2). Pure TiO2 is only photoactive at wavelengths below 380 nm. This is because a certain amount of light energy is required to bump the electrons around and cause the behaviours that we associate with photocatalysis. The UV LED in the PeCOD® COD Analyzer operates at a peak wavelength of 365 nm, with a minimum 360 nm and maximum 370 nm, ensuring that efficient photocatalysis is achieved.