Key Laboratory of Groundwater Circulation and Evolution China University of Geosciences Beijing

Haidian District, China

Key Laboratory of Groundwater Circulation and Evolution China University of Geosciences Beijing

Haidian District, China
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Liu H.,Key Laboratory of Groundwater Circulation and Evolution China University of Geosciences Beijing | Liu H.,Water Resources University | Chen N.,Key Laboratory of Groundwater Circulation and Evolution China University of Geosciences Beijing | Chen N.,Water Resources University | And 4 more authors.
Bioresource Technology | Year: 2017

This study aimed to investigate the effect of electro-stimulation on denitrifying bacterial growth in a bio-electrochemical reactor, and the growth were modeled using modified Gompertz model under different current densities at three C/Ns. It was found that the similar optimum current density of 250 mA/m2was obtained at C/N = 0.75, 1.00 and 1.25, correspondingly the maximum nitrate removal efficiencies were 98.0%, 99.2% and 99.9%. Moreover, ATP content and cell membrane permeability of denitrifying bacteria were significantly increased at optimum current density. Furthermore, modified Gompertz model fitted well with the microbial growth curves, and the highest maximum growth rates (µmax) and shorter lag time were obtained at the optimum current density for all C/Ns. This study demonstrated that the modified Gompertz model could be used for describing microbial growth under different current densities and C/Ns in a bio-electrochemical denitrification reactor, and it provided an alternative for improving the performance of denitrification process. © 2017 Elsevier Ltd


Li Y.,Water Resources University | Li Y.,Key Laboratory of Groundwater Circulation and Evolution China University of Geosciences Beijing | Zhang B.,Water Resources University | Zhang B.,Key Laboratory of Groundwater Circulation and Evolution China University of Geosciences Beijing | And 6 more authors.
Journal of Hazardous Materials | Year: 2016

Arsenic is one of the most toxic elements commonly found in groundwater. With initial concentration of 200μgL-1, spontaneous As(III) oxidation is realized completely during 7 days operation in single-chamber microbial fuel cells (MFCs) in the present study, with the maximum power density of 752.6±17mWm-2. The product is less toxic and mobile As(V), which can be removed from aqueous solution more easily. High-throughput 16S rRNA gene pyrosequencing analysis indicates the existence of arsenic-resistant bacteria as Actinobacteria, Comamonas, Pseudomonas and arsenic-oxidizing bacteria as Enterobacter, with electrochemically active bacteria as Lactococcus, Enterobacter. They interact together and are responsible for As(III) oxidation and bioelectricity generation in MFCs. This study offers a potential attractive method for remediation of arsenic-polluted groundwater. © 2015 Elsevier B.V.


Zhou X.,Water Resources University | Zhou X.,Key Laboratory of Groundwater Circulation and Evolution China University of Geosciences Beijing | Shen Y.,Water Resources University | Shen Y.,Key Laboratory of Groundwater Circulation and Evolution China University of Geosciences Beijing | And 4 more authors.
Journal of Ocean University of China | Year: 2015

Natural weak acidic groundwater occurs in the unconfined and confined aquifers consisting of Quaternary and Neogene unconsolidated sediments near Beihai in southern Guangxi, China. Under natural conditions the groundwater has low TDS (less than 200 mg L−1) and low concentrations of trace elements (less than 100 µg L−1) with a deceasing tend in contents of the Lanthanides (rare earth elements, less than 1 µg L−1) towards higher atomic number. The groundwater ranges in pH from 3.33 to 7.0 with an average value of 5.12 (even lower than that of local rainwater, 5.88). pH values in the groundwater are a bit higher in rainy seasons than those in dry seasons and do not show significant increasing or decreasing trend with time. The average pH value in groundwater in the confined aquifers is even a bit lower than that in the unconfined aquifer. Comprehensive analyses of the groundwater environment suggest that H+ in the groundwater may be derived from dissociation of H2CO3, release of the absorbed H3O+ in clay layers and the acidity of rainwater. The H2CO3 in the groundwater may be formed by dissolution of CO2 (g). Minerals in the unconsolidated sediment are predominated by quartz with small amount of clay minerals. The sediments undergoing a long-term weathering contain low levels of soluble constitutes. Lack of alkaline substances in the groundwater system is also helpful in the accumulation of acidity of the groundwater. © 2015, Science Press, Ocean University of China and Springer-Verlag Berlin Heidelberg.


Zhang B.,Water Resources University | Zhang B.,Key Laboratory of Groundwater Circulation and Evolution China University of Geosciences Beijing | Tian C.,Water Resources University | Tian C.,Key Laboratory of Groundwater Circulation and Evolution China University of Geosciences Beijing | And 8 more authors.
Bioresource Technology | Year: 2015

Simultaneous microbial and electrochemical reductions of vanadium (V) with bioelectricity generation were realized in microbial fuel cells (MFCs). With initial V(V) concentrations of 75mg/l and 150mg/l in anolyte and catholyte, respectively, stable power output of 419±11mW/m2 was achieved. After 12h operation, V(V) concentration in the catholyte decreased to the value similar to that of the initial one in the anolyte, meanwhile it was nearly reduced completely in the anolyte. V(IV) was the main reduction product, which subsequently precipitated, acquiring total vanadium removal efficiencies of 76.8±2.9%. Microbial community analysis revealed the emergence of the new species of Deltaproteobacteria and Bacteroidetes as well as the enhanced Spirochaetes mainly functioned in the anode. This study opens new pathways to successful remediation of vanadium contamination. © 2014 Elsevier Ltd.


Liu H.,Key Laboratory of Groundwater Circulation and Evolution China University of Geosciences Beijing | Liu H.,Water Resources University | Tong S.,Key Laboratory of Groundwater Circulation and Evolution China University of Geosciences Beijing | Tong S.,Water Resources University | And 9 more authors.
Bioresource Technology | Year: 2015

The effects of electro-stimulation on heterotrophic denitrifying bacterial activity and nitrate removal were investigated using a bench-scale bio-electrochemical reactor in this study. Results showed that the maximum nitrate removal efficiency was 100% at the optimum current density of 200mA/m2, at which low nitrite production and high ATP aggregate level were obtained. The activity of denitrifying bacteria was highest at the range densities of 200-250mA/m2, although the terminative pH increased to 8.62 at 200mA/m2 and 9.63 at 250mA/m2. This demonstrates that suitable current densities could improve the activity of denitrifying bacteria. Therefore, this study provides a number of useful information to improve the bio-electrochemical reactor designs and promote the removal efficiency of pollutants. © 2015 Published by Elsevier Ltd.


He Q.,Key Laboratory of Groundwater Circulation and Evolution China University of Geosciences Beijing | He Q.,Water Resources University | Feng C.,Key Laboratory of Groundwater Circulation and Evolution China University of Geosciences Beijing | Feng C.,Water Resources University | And 4 more authors.
Ecological Engineering | Year: 2016

This research used an upflow zeolite-based biofilm reactor (UZBR) with rice washing drainage (RWD) as carbon source to improve denitrification efficiency and simultaneously treat RWD in the process. Removal performance in two UZBRs inoculated with and without activated sludge was investigated at different ratios of RWD to synthetic nitrate-contaminated groundwater (1/3 (v/v), 1/5.5 (v/v), 1/8 (v/v)). At optimum conditions (1/5.5 (v/v)), nitrate removal efficiencies reached 97.0% ± 2.0% with activated sludge and 98.2% ± 1.1% without activated sludge, and TOC concentration in RWD decreased by 80.6% ± 1.1% and 88.6% ± 3.9%, respectively. Illumina sequencing analysis revealed that the microbial community structures in the reactor with activated sludge differed with the reactor without the activated sludge. RWD itself generated polyphosphate accumulating organisms (PAOs) without the breeding of glycogen accumulating organisms (GAOs). Further, the read counts of denitrifiers were more at the bottom and middle of the reactor than at the top. It has been suggested that RWD could provide electron donors and denitrifiers for denitrification and simultaneously treat RWD on-site in a reactor. © 2016 Elsevier B.V.


Gao J.,Water Resources University | Zhou X.,Water Resources University | Zhou X.,Key Laboratory of Groundwater Circulation and Evolution China University of Geosciences Beijing | Fang B.,Water Resources University | And 3 more authors.
Quaternary International | Year: 2013

High resolution age data obtained by travertine dating is necessary for the reconstruction of paleoclimate and palaeohydrology near Rongma hot springs in northern Tibet. U-series dating of a travertine cone depositing in the study area was used. The results show that the U contents of the travertine samples range from 0.298 to 1.363 ppm, and the 234U/238U is in the rage of 1.475-1.700, indicating that the deposition of travertine near the Rongma hot springs is stable and continuous. The age of the travertine samples ranges from 11,500 to 4600 a, corresponding to the first stage of MIS 1. Combination of the first stage of MIS with the effect of monsoon climate of the Indian Ocean in the same period implies a warm and humid climate during the deposition of the travertines in the study area. The U-series age range in the Rongma hot springs area is coincident with that of the travertine in southern Tibet. The age data detected from travertine cone help in understanding the evolution of hydrogeology of the hot spring area. High resolution age data must be acquired before travertine can be confidently used as a paleoclimatic archive. © 2012 Elsevier Ltd and INQUA.

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