Fast, green, accurate Chemical Oxygen Demand analysis
MANTECH’s revolutionary PeCOD® COD Analyzer technology provides accurate chemical oxygen demand (COD) results in 15 minutes — without the use of harmful chemicals including dichromate and mercury. Highly adaptable for wastewater and drinking water applications, the PeCOD® COD Analyzer’s patented nanotechnology-based approach to COD analysis will save you time and money while protecting the environment and the health and safety of your workers.
peCOD is the fastest available method for quantifying chemical oxygen demand (COD), 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.
peCOD nanotechnology provides a higher oxidizing power and none of the risks associated with harmful chemicals such as dichromate and mercury used in traditional COD analysis. It’s safe and simple to use for any laboratory or operations staff member at any point in the process.
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 COD.
The PeCOD® COD Analyzer technology is a proven performer in a variety of municipal and industrial wastewater applications. Recent studies have shown a strong correlation between the 15 minute peCOD method for testing chemical oxygen demand (COD) and standard dichromate COD (CODCR) and five-day BOD (BOD5) methods. In most cases, peCOD can be used as a BOD screening tool, providing accurate BOD estimates in just minutes versus several days.
The PeCOD® COD Analyzer will be the technology of choice as new regulations take effect in Europe in September 2017 that will eliminate the use of dichromate in COD testing. peCOD conforms to Method E3515, released in 2014 by the Ontario Ministry of Environment and Climate Change (MOECC) to replace the dichromate method for COD testing. peCOD is also included as an approved alternate COD method in the Protocol for the Sampling and Analysis of Industrial/Municipal Wastewater which was updated in 2016 by the MISA (Municipal Industrial Strategy for Abatement) program.
The PeCOD® COD 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® COD 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® COD Analyzer is MANTECH’s base model for use in industrial, municipal or 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 chemical oxygen demand (COD) analysis is also available in a portable field unit. Just add the battery and carrying case and COD can be measured in the field without the need to transport toxic or hazardous reagents.
- 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® COD 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 COD results
- Option to add automated pH adjustment and dilutions
- Additional parameters can be added on, including pH, conductivity, alkalinity, and ammonia
Frequently Asked Questions
Chemical Oxygen Demand (COD) analysis is a measurement of the oxygen-depletion capacity of a water sample contaminated with organic waste matter. Specifically, it measures the equivalent amount of oxygen required to chemically oxidize organic compounds in water. COD is used as a general indicator of water quality and is an integral part of all water quality management programs. Additionally, COD is often used to estimate BOD (Biochemical Oxygen Demand) as a strong correlation exists between COD and BOD, however COD is a much faster, more accurate test. Learn more here.
Chemical Oxygen Demand (COD) analysis is a measurement of the oxygen-depletion capacity of a water sample contaminated with organic waste matter. Specifically, it measures the equivalent amount of oxygen required to chemically oxidize organic compounds in water. The traditional COD method is the wet chemistry method, dichromate COD (CODCr). This involves a two hour digestion at high heat under acidic conditions and involves hazardous chemicals such as mercury and dichromate.
Biochemical Oxygen Demand (BOD), also often referred to as biological oxygen demand, is a test performed to measure the potential of wastewater and other waters to deplete the oxygen level of receiving waters. The BOD test involves taking an initial dissolved oxygen (DO) reading and a second reading after five days of incubation at 20°C. For this reason, this test is often written as BOD5 for short.
MANTECH has developed an automated COD method utilizing a new, rapid and green technology called the PeCOD® COD Analyzer. This method directly measures the amount of oxidizable material in a sample via photoelectrochemical oxidation in a microcell, eliminating the need for time-consuming digestion and hazardous chemicals as only an electrolyte solution is required for analysis.
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 COD 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.
KHP (Potassium Hydrogen Phthalate) has historically been a common reference standard used in a variety of chemistry applications including the traditional dichromate COD test, where it does provide a result close to the theoretical COD result, and for TOC analysis. KHP is not recommended for use in the PeCOD COD analysis as it over reports compared to the theoretical COD amount. This is predominantly due to some pre-concentration of the molecule on the surface of the PeCOD sensor prior to analysis which is a peculiarity of KHP with the PeCOD COD method.
It is important to note that for all COD methods there are specific molecules whereby the individual analytical result is not well aligned to the theoretical value. For instance, organic compounds such as propionic acid, diethylamine or nicotinic acid could not be used as a COD standard for the dichromate COD method due to poor correlation to theoretical results but could be suitable for the PeCOD COD method. It is therefore important to chose a standard that provides a strong correlation to the theoretical result for the method employed, is a good reflection of the samples to be analysed, is suitable for general laboratory use and is readily available. For details on preparing sorbitol and glucose-based COD standards for the PeCOD COD method, read our technical bulletin 2017-029: PeCOD Standard Recipe.
pH Range: 4.0 – 10.0 (after mixing with electrolyte)
The peCOD method requires that the pH of a sample AFTER being mixed with electrolyte must be between 4 – 10. To determine if a sample must be pH-adjusted, mix the sample with peCOD electrolyte at the proper mixing ratio for your COD range, then test the pH of the mixture.
For example, the sample may have a pH of 3.0, but then after preparing with electrolyte, the pH is in the required range, therefore, it is acceptable for immediate peCOD measurement.
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 photo-active at wavelengths below 380 nm. This is because a certain amount of light energy is required to bump the electrons around and cause the behaviors 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.