Total phosphorus refers to the sum of organophosphorus and inorganic phosphorus in granular or soluble state in the water. Total phosphorus reflects the polluted level of the water polluted by phosphorus.
Common Chromium compounds of Cr are in tervalence or sexavalence. It is generally believed that the poison of sexavalence chromium is 100 times higher than that of tervalence chromium and easier for people to absorb and then accumulate in human body and finally lead to liver cancer. Therefore, sexavalence is taken as one of the indicators in the total quantity control in China.
Measurement of organic matter in water. The organic matters in dissolved state can absorb the UV-light, so the amount of the organic matters in the water can be measured through the measurement of the UV-light absorbed by the water sample.