BCODcr-20 automatic chemical oxygen demand (dichromate method) analyzer is an analytical system independently developed by Baode for measuring the chemical oxygen demand in water. The instrument is fully designed according to the standard (HJ828-2017), and the entire measurement process meets the standard requirements. The potassium dichromate method is used to measure the chemical oxygen demand in water. The entire machine adopts an integrated design, with a reasonable structure, automatic reagent addition, stable performance, intelligent detection, and accurate data.

Instrument principle :

The potassium dichromate method involves adding a known amount of potassium dichromate solution to a water sample, using silver salt as a catalyst in a strong acid medium, boiling and refluxing, and using ferrous ammonium sulfate as an indicator to titrate the unreacted potassium dichromate in the water sample. The mass concentration of oxygen consumed is calculated based on the amount of potassium dichromate consumed.

According to the standard HJ 828-2017, the instrument automatically adds mercury sulfate solution and potassium dichromate standard solution to the water sample in sequence. Silver sulfate sulfuric acid solution is added from the upper mouth of the condenser tube and kept under micro boiling reflux for 2 hours. After air cooling, pure water is automatically added from the upper mouth of the condenser tube. After continuing to air cool to room temperature, a test iron indicator is added, and ammonium ferrous sulfate is automatically titrated to identify and determine the titration endpoint. The software automatically calculates the chemical oxygen demand of the water sample. And the instrument achieves simultaneous and independent determination of high and low concentration samples, without cross contamination, and the data is stable and accurate.

Instrument characteristics

Ø Integrated design of the entire machine, reasonable structure, and space saving

Ø 22 samples are heated and digested to achieve batch sample detection

Ø Independent ammonium ferrous sulfate labeling without occupying digestion sites

Ø Adopting an integrated heating module, the overall power is controllable and the digestion conditions can be freely adjusted

Ø Special heat conduction materials, with uniform heat conduction, fast heating rate, corrosion resistance, and oxidation resistance, ensure the consistency of sample heating

Application Area

Suitable for industrial wastewater with high chemical oxygen demand, such as surface water, domestic sewage, wastewater from sewage treatment plants, pharmaceutical wastewater, textile wastewater, printing and dyeing wastewater, papermaking wastewater, pesticide wastewater, metallurgical wastewater, etc.