Environmental protection has always been a concern for us, as water pollution has become increasingly serious with the continuous development of society! Now, what we need to do is how to prevent and protect water quality problems. So, why monitor the concentration of hexavalent chromium in water? Let’s find out together with the water quality online monitoring instrument manufacturers!
What is Chromium?
Chromium can be found in various media in the environment, including the atmosphere, water bodies, and soil. It was discovered by French chemist Vauquelin in 1797 from the red lead ore in Siberia. In 1798, Vauquelin named the gray needle-shaped metal he found chrom, which comes from the Greek word chroma (color). Thus, the Latin name chromium and the element symbol Cr were obtained. Since chromium has an impact on the environment, plants, animals, and human health, it has been listed in China’s priority pollutants list for water environment and is implemented with priority monitoring and management.
What Impact Soes Chromium in Qater Wxceeding the Atandard Have on the Environment?
Chromium pollution exists in water, and chromium in the environment can be accumulated in plants and animals through the food chain and enter the human body, endangering human health. Some hexavalent chromium compounds have been found to have carcinogenic effects in the body.
Hexavalent chromium dissolves in water, and in natural water bodies, it is stable in the presence of oxygen and easily adsorbed by colloidal particles to precipitate, reducing its concentration. In anaerobic conditions, hexavalent chromium can be reduced to trivalent chromium. Trivalent chromium is unstable in water and can form insoluble hydrated chromium oxide precipitates when the pH value of the water is between 7.02 and 9.8. The more hydrated chromium oxide precipitates are formed, the higher the concentration of hydroxychromium. When the hexavalent chromium quality concentration in water is 0.1mg/L, it produces toxicity and has high toxicity and intractability.
In recent years, there are still a number of reports of electroplating wastewater pollution of well water, Cr6+ more than 3 to 10 times China’s health standards, drinking well water contaminated by chromium, resulting in many people with varying degrees of poisoning symptoms. There is an electroplating factory in China, whose wastewater is discharged into two 4 ~ 5m deep seepage Wells, the amount of chromium discharged from the wastewater is only 2.3 ~ 40mg, but after 6 ~ 7a accumulation, the nearby groundwater is polluted. In the 1 drinking well 100m away from the seepage well, the mass concentration of chromium VI is as high as 2.0 ~ 4.0mg/L, and the water quality turns yellow. The cumulative pollution can not be ignored.
What Instruments are Used to Monitor Hexavalent Chromium in Water?
The T8000-Cr hexavalent chromium online analyzer uses acid oxidation to determine the characteristic developing agent after masking interference ions, which has wider applicability and accuracy than the anodic stripping voltammetry method. The pre-treated water sample is injected into the colorimetric pool by the injection pump, and then the masking agent is added to eliminate the influence of interference substances, and then the pH of the solution is adjusted. In the appropriate pH conditions add characteristic color developer for color reaction, in the measuring range of the color change of the solution is proportional to the concentration of hexavalent chromium in the water sample, by measuring the color change of the solution, the content of hexavalent chromium in the water sample can be calculated. If the total chromium is measured, the oxidizer is added to the automatic line after pretreatment to oxidize the chromium of various valence states into hexavalent chromium, and then the colorimetric determination is carried out.
