Entity

Time filter

Source Type

Beijing, China

Liu H.,Jilin University | Liu H.,Jilin Institute of Chemical Technology | Zhang L.,Jilin University | Deng H.,Jilin University | And 2 more authors.
Environmental Monitoring and Assessment | Year: 2011

A multi-media bio-PRB reactor was designed to treat groundwater contaminated with petroleum hydrocarbons. After a 208-day bioremediation, combined with the total petroleum hydrocarbons content in the groundwater flowed through the reactor, microbiological characteristics of the PRB reactor including microbes immobilized and its dehydrogenase activity were investigated. TPH was significantly reduced by as much as 65% in the back of the second media layer, whereas in the third layer, the TPH content reached lower than 1 mg l -1. For microbes immobilized on the media, the variations with depth in different media were significantly the same and the regularity was obvious in the forepart of the media, which increased with depth at first and then reduced gradually, while in the back-end, the microbes almost did not have any variations with depth but decreased with the distance. The dehydrogenase activity varied from 2.98 to 16.16 mg TF L -1 h -1 and its distribution illustrated a similar trend with numbers of microbial cell, therefore, the noticeable correlation was found between them. © Springer Science+Business Media B.V. 2011. Source


Chang Y.-M.,Water Resources University | Yang Q.,Water Resources University | Hao C.-B.,Water Resources University | Shang H.-T.,Water Resources University | Jiang T.-S.,Beijing Hydrologic Center
Huanjing Kexue/Environmental Science | Year: 2011

Activated sludge of municipal wastewater treatment plant was domesticated by sulfur as the electron donor under autotrophic. The sludge activity was determined by measuring growth rate of sludge. The removal efficiency of nitrate and sulfate production efficiency were analyzed by continuously measuring the concentration of NO 3 --N and SO 4 2-. When the removal efficiency of nitrate was more than 90%, 16S rRNA genetic libraries were built up to compare their microbial biodiversity. The growth rate of sludge is 0.177 g/(L·d). The relation between concentration of nitrate and time meets first order reaction kinetics. The bacteria in the sludge affiliated with Beta-Proteobacteria, Deta-Proteobacteria, Gamma-Proteobacteria and Unclassified bacteria. Beta-Proteobacteria is the main phylum in the sludge. Bacteria related to Thiobacillus denitrificans from denitrifying bioreactor perform 48.65%. In addition, the bacteria of Denitratisoma sp., Curvibacter sp., Thermomonas sp., Geobacter sp. are existed in the sludge. The study of autotrophic denitrifying bacteria diversity is conducive to optimization of reaction conditions and efficient removal of nitrate. Source


Liu X.,CAS Beijing Institute of Geographic Sciences and Nature Resources Research | Dai X.,Chinese Ministry of Water Resources | Zhong Y.,Beijing Hydrologic Center | Li J.,Bureau of Hydrology | Wang P.,Jiangxi Normal University
Theoretical and Applied Climatology | Year: 2013

The Yiluo River is the largest tributary of the middle and lower Yellow River below the Sanmenxia Dam. Hydro-climatic variables have changed in the Yiluo River during the last half century. In this study, the trends in the annual precipitation and streamflow were analyzed in the Yiluo River during 1960-2006. The results indicated that both the annual precipitation and streamflow decreased significantly (P < 0.05) from 1960 to 2006. Pettitt's test shows that there was a change point for annual streamflow series around the year 1986 (P < 0.05), while there was no change point identified for the annual precipitation series from 1960 to 2006. Annual streamflow decreased more significantly than annual precipitation since 1986. The relationship between the annual precipitation and streamflow presented a non-stationary state since 1986. This non-stationary relationship was mainly influenced by human activities. The average annual amount of water diversion from the Yiluo River increased significantly since the mid-1980s, accounting for 31.3 % of the total streamflow decrease from 1986 to 2006. In addition, land use/cover change (LUCC) contributed to 27.1-29.8 % of the decrease in streamflow. Human activities, including water diversion and LUCC, together contributed to 58.4-61.1 % of the decrease in streamflow and led to the non-stationary relationship between the annual precipitation and streamflow from 1986 to 2006. This study detected the changes in the precipitation-streamflow relationship and investigated the possible causes in the Yiluo River, which will be helpful for the understanding of the changes in streamflow in the Yellow River Basin. © 2013 Springer-Verlag Wien. Source


Han Y.,Beijing Forestry University | Li B.,Beijing Hydrologic Center | Kong Q.,Beijing Water Conservancy School | Wang Y.,Beijing Forestry University
Journal of Food, Agriculture and Environment | Year: 2013

Soil moisture sensor is of greater significance for timely irrigation and crop yield increase to use soil moisture sensors to measure soil water content so as to guide irrigation. Due to high cost of the soil moisture sensor, the investment in the irrigation system will necessarily increase and the promotion of the system will be affected if a large number of sensors are buried in different depths at the same soil profile. Therefore, determination of the optimal position for burying soil moisture sensors is quite important for wide application and promotion of the sensors since a general water condition of the whole soil may be obtained by using fewer sensors. In this paper, based on soil moisture data measured during the experiment, an optimal depth for burying soil moisture sensors is analysed for tomato irrigation. The results showed that soil water content in 10-20 cm layer can best reflect the mean soil water content in the designed irrigation layer (R2 is above 0.95 and 0.85 at lowering and fruit bearing stage and fruit stage, respectively). Therefore, 10-20 cm layer is an ideal depth for burying soil moisture sensors. Source


Han Y.,Beijing Forestry University | Yu X.,Beijing Forestry University | Yang P.,China Agricultural University | Li B.,Beijing Hydrologic Center | And 2 more authors.
Environmental Earth Sciences | Year: 2013

Drought is a great concern in agricultural yield. Super-absorbent polymers (SAPs) can assist in easing water shortage. Therefore, it is significantly important to study the water absorbing and desorbing capacity of SAPs when applied into soil as well as their effective time. The aim of this study was to investigate the effect of different SAP types under the same moisture condition and the effect of the same SAP type under different moisture conditions on saturated soil water content, saturated soil hydraulic conductivity and soil water diffusivity. With SAP application, saturated soil water volumetric content increased significantly, up to 0. 186 cm3 cm-3, while saturated hydraulic conductivity and diffusivity significantly decreased because the soil pores were blocked by SAP's swelling volume during the repeated wetting and drying cycles. After SAPs were mixed in the soil, their capacity of absorbing and desorbing water showed a downward trend with time and outside water condition. Under a relatively stable water condition, such capacity reduced more slowly. As for the soil with SAP application, successful simulation for diffusivity D(θ, T) was also applicable to other parameters of the equation of water movement, which made it possible to study the water movement under the same condition. © 2012 Springer-Verlag. Source

Discover hidden collaborations