High-Throughput Sequencing Technology And Its Application In Contamination Of Groundwater

Groundwater is generally contaminated due to excessive human activities.Microbial communities are an active factor of mattter cycle,energy conversion and information transmission in contaminated groundwater environment.High-throughput sequencing technology as a high-new technology can detect culturable bacteria and uncultured bacteria and produce large volumes of data,but the application of the technology is very limited in the region investigation of groundwater contamination.Application of high-throughput sequencing technology in contamination of groundwater can provide the new contents for investigation of groundwater contamination and scientific basis for natural attenuation evaluation and bioremediation of groundwater contamination by deep mining data information.In this paper,the author systematically summarized high-throughput sequencing technology and its application progress in contamination of groundwater,and selected Liuli River area in Fangshan,Beijing as study area.28 groups of hydrochemistry samples and 15 samples of microorganism were collected for application study of high-throughput sequencing technology in groundwater contamination.The main results obtained were as follows:1.The results of groundwater chemistry and contamination analysis showed that the content ranges of TDS,NO3-,SO42-and Cl-were 372.2?1286.0 mg/L,0.68?166.0 mg/L,3.41?321.0 mg/L and 8.75?216.4 mg/L in study area,respectively,and the concentration of NO3-over 50 mg/L were 35%of the total samples.The main type of hydrochemistry was HCO3-Ca·Mg,and HCO3·SO4-Ca and HC03O·SO4-Ca·Na were found in northwest part of the study area.The results of comprehensive evalution of groundwater contamination revealed that groundwater identified as non-contamination level and groundwater identified as different contamination levels accounted for 71.4%and 28.6%of total samples,respectively.The samples of NO3-contents exceeded the 50 mg/L and the samples identified as moderate-level contamination were mainly distributed in Northwest Doudian of the study area.2.The diversity and structure of microbial communities were analyzed,and the differences of diversity and composition of microbial communities between the different contamination areas were compared by using high-throughput sequencing results of groundwater microbial samples.The main bacterium groups at phylum-level were Proteobacteria,Firmicutes,Bacteroidetes,Omnitrophica and Actinobacteria,and the main bacterium groups at genus-level were Pseudomonas,Malikia,Acidovorax,Hydrogenophaga,Aquabacterium in groundwater of the moderate-level contamination area.The main bacterium groups at phylum-level were Proteobacteria,Bacteroidetes,Nitrospirae,Omnitrophica,Cyanobacteria,and the main bacterium groups at genus-level were Rhodoferax,Arcobacter,Hydrogenophaga,Nitrospira,Acidovorax in groundwater of the light-level contamination area.741 genera of bacteria were found in both the moderate-level contamination area and light-level contamination area,and 126 genera and 145 genera of bacteria were found in the moderate-level contamination area and the light-level contamination area,respectively.3.Correlation analysis showed that the degree of hydrochemistry influencing on microbial communities was DO>NO->SO42->TDS>HCO3->COD>pH.Thiothrix was negatively correlated with NO3-,SO42-and TDS.Rhodoferax,Acidovorax and Vogesella were positively related to some hydrochemical factors respectively.Rhodoferax,Nitrospira and Gallionella were closely correlated with pH and HCO3-,and Rhodococcus,Aquabacterium,Acidovorax and Pseudomonas were related with DO.4.There were some microbial community related with denitrification and sulfate reduction in groundwater of the study area,which indicated that it had potential to reduce NO3-and SO42-in relatively heavy contaminated groundwater of the Northwest Doudian.