Microbial community composition and environmental response characteristics of typical brackish groundwater in the North China Plain

To reveal the microbial community composition of regional shallow porous brackish groundwater and its response characteristics to groundwater environment,the first and second aquifers in Taocheng District,Hengshui City were selected,and 10 groundwater source samples were collected for hydrochemical analysis and microbial 16S RNA gene V4-V5 regional sequencing.The results showed that the shallow brackish groundwater in the study area is weakly alkaline and has high ion content.The hydrochemical types are SO_(4)·Cl-Na·Mg type and HCO3·Cl-Na·Mg type as a whole.The spatial zonation of the abundance and diversity of groundwater microorganisms is obvious.The number of endemic bacteria in groundwater from upstream,midstream to downstream is 11,135 and 22 respectively,with a total of 22 bacteria.Proteobacteria is the most dominant in groundwater level(38.82%-86.88%),and there are obvious differences in different sections.At the genus level,the main dominant species in each group and sample are Pseudomonas and Hydrogenophaga.In terms of composition difference,Pseudohongiella,Pseudorhodobacter and Limnohabitans are the representatives of UR,MR and LR.On the whole,the composition of flora in groundwater in the study area is sensitive and closely related to hydrochemical processes.Species abundance is affected by alkaline and high salinity environmental indicators,while species diversity is related to depth and dissolved oxygen in weak reduction environment.

A mine drainage treatment system for AMD in remediation of metal sulfide mines

1. Objective In the process of mining, sorting and smelting metal sulfide mines, a large amount of acid mine drainage (AMD) containing concentrated sulfate (SO4 ^2-) and various metal elements (Fe, Mn, Cu, Zn, Ni, etc.) are produced. In order to solve current problems of mine acid drainage, we have improved the existing repair technology based on biogeochemical technology, and provided a new treatment system for AMD from metal sulfide mines.

Distribution of aromatic amines,phenols,chlorobenzenes,and naphthalenes in the surface sediment of the Dianchi Lake,China

Organic pollutants are widespread environmental pollutants with high toxicity,persistence,and bioaccumulation.Our aim was to investigate the distribution of aromatic amines,phenols,chlorobenzenes,and naphthalenes in the surface sediment of the Dianchi Lake,China.Nineteen surface sediment samples were collected from the Dianchi Lake,and 40 types of organic pollutants were analyzed via gas chromatography-mass spectrometry.The total organic pollutant concentrations in the surface sediment of the Dianchi Lake varied from 27.4 to 1.62×10^3 ng/g.The concentrations of phenols were much higher than those in other water bodies but still within a controllable range,whereas the concentrations of the other organic pollutant classes were similar or even lower.The detection ratio of 3-or 4-methylphenol was the highest(100.00%)among the pollutants.The average total organic pollutant concentrations decreased in the following order:Caohai(540 ng/g)>the middle of Waihai(488 ng/g)>the edge of Waihai(351 ng/g)>Haigeng Dam(90.4 ng/g).Pearson analysis showed a strong correlation among 1-methylnaphthalene,2-methylnaphthalene,1,3-dinitronaphthalene,and 1,4-dinitronaphthalene(P<0.01).Caohai,the north lakeshore of Waihai and the south of Waihai showed higher risk because of high concentration;meanwhile,1,4-dichlorobenzene,3-or 4-methylphenol and 1,2,4-trichlorobenzene were mor e likely to cause risks.