TDS value is 0~9, which is pure water; TDS value is 10~60, which is mountain spring water and mineralized water; TDS value is 60~ 100, which is pure water; TDS value is 100~300, which is tap water. If the TDS value is above 300, it is polluted water. Therefore, the TDS value of water must be below 300 to be considered healthy.
TDS value is generally used to measure the purity of pure water, which is the abbreviation of total dissolved solid matter and refers to the concentration of total dissolved matter in water. If the concentration of heavy metal ions in drinking water exceeds the standard, it will pose a great threat to human health. Therefore, human drinking water must meet the microbial indicators, toxicological indicators, sensory characteristics, general chemical indicators and radioactive indicators.
According to the national sanitary standard for drinking water, the TDS of drinking tap water is limited, that is, the total dissolved solids are ≤ 1000mg/L, which is regarded as up to the standard. Usually within 300% of daily drinking water and 50% of direct drinking water. However, attention should be paid to the size of TDS, which cannot reflect whether the concentration of harmful heavy metal ions, bacteria and nitrite in water exceeds the standard.