Groundwater hydrogeochemical characteristics and quality suitability assessment for irrigation and drinking purposes in an agricultural region of the North China plain

Eighty-one samples from both shallow and deep aquifers were collected and analyzed to reveal groundwater hydrogeochemical characteristics and estimate groundwater quality suitability for irrigation and drinking purposes based on groundwater quality indexes models including the sodium adsorption ratio (SAR), residual sodium carbonate (RSC), solute sodium percentage (%Na), magnesium hazard (MH), permeability index (PI) and health risk model. The results from groundwater quality suitability assessment indicated that shallow groundwater in the most part of the study region was suitable for irrigation regardless of EC, RSC and MH, while groundwater from the deep aquifer was suitable for irrigation purpose in nearly all parts of the study region. 24.49% and 14.29% of the deep groundwater sampling locations presented high fluoride (F-) concentrations exceeded the Grade III value (1 mg/L) from Quality Standard for Groundwater of China and the maximum permissible value of 1.5 mg/L recommended by the WHO for drinking use, respectively. Non-carcinogens hazard quotient (HQ) values of NO3--N, NH4+-N, NO2--N, Fe, and Mn with the exception of F- were all within the acceptable safety limit (HQ<1). Efficient strategies and scientific decisions were suggested for groundwater resource protection and water quality improvements should be adopted for sustainable groundwater exploitation.

Automated summary

The study revealed that both shallow and deep groundwater in most parts of the study region were suitable for irrigation purposes, but some deep groundwater had high fluoride concentration issues. Hazard quotient values of pollutants, except for fluoride, were within the acceptable safety limit.