Search

In order to understand the interaction between surface water and groundwater in Qingshuihe Basin of Chongli Area, the environmental isotopic D, 18O and 222Rn in surface water and groundwater have been analysis, the study results show that: the calculation results based on the D and 18O, the surface water in middle stream of Donggou River has been recharged by groundwater and river water upstream, the percentage of groundwater recharge is 56%; the calculation results based on the 222Rn, the average seepage rate of surface water is 27.8 m3/d/m in the upstream section, and the average recharge rate of groundwater is 17.6 m3/d/m. It is concluded that, the groundwater and surface water interaction is the main characteristics and processes of water cycle in Qingshuihe Basin, and groundwater recharge is the main sources of surface water in draught seasons. [ABSTRACT FROM AUTHOR]

Nitrogen pollution exceeding the standard because of intensive farming and cropping systems has been a widespread problem in Northeast China. This study investigated the characteristics of functional microorganisms in groundwater in the Bang River farming area. Metagenomic sequencing was used to analyze microbial community structures and Canoco was applied to reveal the response relationship between the microbial community and water environmental factors and to identify changes in the microbial population in response to the addition of electronic donors NH 4 + -N, NO 2 - -N, and NO 3 - -N. The results showed that the dominant microorganisms in groundwater belong to the genera Exiguobacterium, Citrobacter, Acinetobacter, and Pseudomonas, which accounted for more than 40% of the total microbes in the study area. When combined with the results of a water chemical factor test, the dominant bacteria were found to be correlated with Fe 2+ , Mn 2+ , NH 4 + , NO 3 - , NO 2 - , HCO 3 - , DOC, and pH in the water. However, the microbial population changed after the addition of the electron donor, with the genera Pseudomonas, Serratia, Enterobacter, Azomonas, and Ewingella accounting for 97.06% of the total sequences. Indigenous nitrogen-degrading bacteria suitable for low temperature, low oxygen, and oligotrophic groundwater were screened out. The total removal efficiency of NH 4 + -N, NO 2 - -N, and NO 3 - -N in 120 h was 90.83%, 75.04%, and 73.35%, respectively. According to the experimental results, the degradation reaction kinetics followed a pseudo-second-order equation. The results presented herein provide an important scientific basis for the microbial remediation of groundwater contaminated by ammonia.