Total Organic Carbon (TOC), Oil & Grease, Total Phenols Testing

Total organic carbon (TOC) is the measurement of organic carbons found in organic compounds. It is considered to be a better indicator than a BOD or COD test, because it usually oxidizes all of the organic carbon to CO2 at a high temperature of 900 oC with a platinum or cobalt catalyst. The TOC values are used to indicate the pollution level of water.

The term "oil and grease" is used to define petroleum and its derivatives, which are mainly comprised of paraffinic, aromatic and naphthenic hydrocarbons. Due to modernization and urbanizations, the use of petroleum oil and grease products for its energy need at industrial and anthropogenic activities has been increased drastically. Our ecosystem will be in danger when these compounds come into contact with water resources through the discharge of effluents. For example, they can cause an undesirable visual aspect and strong maleodor, exerting a considerable influence on the economic and tourist activities of the region to which they are discharged. It is our call to monitor and control the content of oil and grease in the water to better protect our environment.

Phenolics are a heterogeneous group of natural substances characterized by an aromatic ring with one or more hydroxyl groups. They are classified as simple phenols or polyphenols based on the number of phenol units in the molecule and the number of these compounds identified to date exceeds 100,000. Phenols serve as important raw material and additive, which can be synthesized industrially or produced by plants and microorganisms. On the one hand, it can defense against infection when properly used as medicine, and on the other hand, it poses a threat to our health and environment by its abuse. Phenolic compounds are known to be toxic and inflict both severe and long‐lasting effects on both humans and animals. They act as carcinogens and cause damage to the red blood cells and the liver, even at low concentrations. There is definitely a need to quantify the phenol content before discharge wastewater.

TOC analysis

Fig. 1. TOC automatic detector

There are three commonly recognized methods for the measurement of TOC, which are combustion oxidation, wet oxidation and photocatalytic oxidation. Some analyzers use a combination or mixture of technology. Generally speaking, the combustion method is the most-used technology. There are two ways to test the TOC using TOC automatic detector (Fig 1). Indirectly measurement of TOC includes the analysis of total carbon (TC) and total inorganic carbon (TIC). The TOC can be derived by subtracting TIC from TC. The direct way of measuring TOC involves the remove of inorganic (carbon dioxide, hydrogen carbonate, carbonate) carbon prior to sampling. Nowadays, the technology of photocatalytic oxidation has been explored for TOC analyses, which need the titanium dioxide catalyst and a 400 nm light source for the oxidation process. It can directly measure TOC from a single sample eliminating the loss of purgable organics when compared to the combustion TOC method.

Oil and grease analysis

Since oil and grease have a low solubility and density when in contact with water resources, they form an insoluble and stable film on the surface of water. The detection of oil and grease can be achieved by many technologies such as precipitation, coagulation, chemical oxidation/reduction, sedimentation, filtration, adsorption, reverse osmosis, ion exchange, solvent extraction, and so on.

Total phenols analysis

There are mainly two methods which are titration and colorimetric for the total phenols test. On the one hand, phenols can be oxidized by potassium permanganate due to their reductive chemical property. On the other hand, phenols can usually react with other substances and produce color changes. For example, phenolic hydroxyl can react with the iron ions of tartrate to produce blue complex, and phenolic compounds can react with 4-aminoantipyrine to produce red dye under alkaline conditions. These properties can be used to quantify the phenols content in water as desired. In addition, we can also use other technology such as the extraction method (liquid-liquid extraction or solid phase extraction) and adsorption method to measure the content of total phenols.

Alfa Chemistry is professional in the detection of total organic carbon (TOC), oil & grease, total phenols. We can provide accurate and reliable tests results within the time constraint. Please feel free to contact us if you have any concern or would like us to perform any water testing.

References

• H. T. Boni1, D. de Oliveira1, A. A. Ulson de Souza1, S. M. A. G. Ulson de Souza1. Bioadsorption by sugarcane bagasse for the reduction in oil and grease content in aqueous effluent. Int. J. Environ. Sci. Technol. (2016) 13:1169–1176.

• Zekker I, Rikmann E, Tenno T, Seiman A, Loorits L, Kroon K, Tomingas M, Vabamae P, Tenno T.  Nitritating-anammox biomass tolerant to high dissolved oxygen concentration and C/N ratio in treatment of yeast factory waste water. Envi Technol. (2014) 35(9–12):1565–1576.

• Olumide AS, Morgan A, Peter KJR, Ling SW, McCullagh C. Remediation of oily wastewater from an interceptor tank using a novel photocatalytic drum reactor. Desalin Water Treat. (2011) 26:1–3.

• Robbins, Rebecca J. Phenolic Acids in Foods: An Overview of Analytical Methodology. Journal of Agricultural and Food Chemistry. 2003, 51: 2866–2887.

• Waterman, P.G. & Mole, S. Analysis of Phenolic Plant Metabolites. Blackwell Scientific Publications. Methods in Ecology. Oxford, 1994.