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Microbially induced phosphate precipitation (MIPP) is an advanced bioremediation technology to immobilize heavy metals in soil. In this study, an indigenous bacterial strain LRP3, identified as Rahnella sp., was isolated from Cu-contaminated dark brown soil in the mining area. Strain LRP3 could produce phytase and alkaline phosphatase to degrade phytic acid, which released soluble phosphate to the bacterial culture. Due to the metabolism of bacterial growth, the pH value of bacterial culture was increased. The minimum inhibitory concentration of Cu (II) to bacterial growth in solution was up to 130 mg/L. The bacterial culture could rapidly precipitate Cu (II) in solution through MIPP. The analysis results of Scanning Electron Microscope-Energy Dispersive Spectroscopy (SEM-EDS), Fourier Transform-Infrared Spectrometer (FTIR), and X-ray Diffraction (XRD) revealed that the precipitate form by bacterial culture was rod-shaped Cu3(OH)3PO4 crystal with a diameter of 10 μm. The bacterial culture decreased the content of DTPA-Cu of 83 mg/kg soil in the soil by 58.2%, 61.5% and 75.8% after 5, 10 and 30 days of incubation, respectively, at the temperature of 25 °C. The results indicate that MIPP-based bioremediation by Rahnella sp. LRP3 is a practical, environmental friendly technology for the cleaning-up of copper-contaminated soil.

Agricultural tillage practices play an important role in the production and consumption of greenhouse gases (GHGs) that contribute substantially to the global warming. To explore GHG diffusion characteristic and seek for environment-friendly tillage methods, four tillage systems consisting of continuous rotary tillage (CR), continuous no tillage (CN), ploughing-rotary tillage (PR), and ploughing-no tillage (PN) were designed, and vertical variations of GHG concentrations under different tillage systems were investigated. Mean CO2 concentration in the soil profile was increased significantly with the increase of soil depth. Higher soil moisture promoted CO2 production. However, the influence of soil temperature on the content of CO2 was not obvious. The concentrations of CH4 in soil at 0–20-cm depth were greater than that of 20–40 cm, which was mainly affected by fertilization. The trend of N2O concentration variation in soil was consistent with that of CO2. The diffusion flux of CO2 in soil was all positive, and it changes greatly in the whole growth cycle of maize, which had obvious correlation with precipitation. The CH4 diffusion flux decreased with the increase of soil depth, and the change trend of 0–20-cm soil layer diffusion flux was consistent with the gas concentration. The 20–40-cm soil layer fluctuated greatly, which was mainly affected by water content, and the whole value was negative after jointing. The trend of N2O diffusion flux was similar to that of CH4. In the whole maize growth period, except for CH4 in 20–40-cm soil layer, the cumulative diffusion fluxes of greenhouse gases in each treatment were all positive, indicating that the whole farmland soil was the emission source of greenhouse gases. The effect of three greenhouse gases on greenhouse effect was CO2 > N2O > CH4, and the comprehensive warming potential of different tillage methods was CN > CR > PR> PN. So PN is the best tillage mode to reduce GHG emissions in soil profile under the test conditions.

Studies have found that the Permian is another important stratum for petroleum exploration except the Jurassic coal measures within Turpan–Hami Basin recently. However, the knowledge of the depositional environments and its petroleum geological significances during the Middle–Late Permian is still limited. Based on the analysis about the sedimentological features of the outcrop and the geochemical characteristics of mudstones from the Middle Permian Taerlang Formation and Upper Permian Quanzijie Formation in the Taoshuyuanzi profile, northwest Turpan–Hami Basin, this paper makes a detailed discussion on the Middle–Late Permian paleoenvironment and its petroleum geological significances. The Middle–Upper Permian delta–lacustrine depositional system was characterized by complex vertical lithofacies assemblages, which were primarily influenced by tectonism and frequent lake-level variations in this area. The Taerlang Formation showed a significant lake transgression trend, whereas the regressive trend of the Quanzijie Formation was relatively weaker. The provenance of Taerlang and Quanzijie Formations was derived from the rift shoulder (Bogda Mountain area now) to the north and might be composed of a mixture of andesite and felsic volcanic source rocks. The Lower Taerlang Formation was deposited in a relatively hot–dry climate, whereas the Upper Taerlang and Quanzijie Formations were deposited in a relatively humid climate. During the Middle–Late Permian, this area belonged to an overall semi-saline water depositional environment. The paleosalinity values showed stepwise decreases from the Lower Taerlang Formation to the Upper Quanzijie Formation, which was influenced by the changes of paleoclimate in this region. During the Middle–Late Permian, the study area was in an overall anoxic depositional environment. The paleoenvironment with humid climate, lower paleosalinity, anoxic condition, and semi-deep to deep water during the deposition of the Upper Taerlang Formation was suitable for the accumulation of mudstones with higher TOC values.

True-color three-dimensional (3D) imaging exploits spatial and spectral information and can enable accurate feature extraction and object classification. The existing methods, however, are limited by data collection mechanisms when realizing true-color 3D imaging. We overcome this problem and present a novel true-color 3D imaging method based on a 32-channel hyperspectral LiDAR (HSL) covering a 431–751 nm spectral range. We conducted two experiments, one with nine-color card papers and the other with seven different colored objects. We used the former to investigate the effect of true-color 3D imaging and determine the optimal spectral bands for compositing true-color, and the latter to explore the classification potential based on the true-color feature using polynomial support vector machine (SVM) and Gaussian naive Bayes (NB) classifiers. Since using all bands of HSL will cause color distortions, the optimal spectral band combination for better compositing the true-color were selected by principal component analysis (PCA) and spectral correlation measure (SCM); PCA emphasizes the amount of information in band combinations, while SCM focuses on correlation between bands. The results show that the true-color 3D imaging can be realized based on HSL measurements, and three spectral bands of 466, 546, and 626 nm were determined. Comparing reflectance of the three selected bands, the overall classification accuracy of seven different colored objects was improved by 14.6% and 8.25% based on SVM and NB, respectively, classifiers after converting spectral intensities into true-color information. Overall, this study demonstrated the potential of HSL system in retrieving true-color and facilitating target recognition, and can serve as a guide in developing future three-channel or multi-channel true-color LiDAR.

A diverse and well-preserved fossil wood assemblage is described, for the first time, from the Middle Permian Taerlang Formation and the Upper Permian Quanzijie Formation in the vicinity of the Tianshan Town, Hami City of northwestern China. On the basis of wood microstructure, the fossil woods are classified into three genera and five species, including one new genus: Prototianshanoxylon gen. nov. and two new species: Prototianshanoxylon erdaogouense sp. nov., Prototianshanoxylon hamiense sp. nov. The new genus is characterized by window-like cross-field pitting and mixed tracheid radial wall pitting that suggest a transitional type between araucarioid-type and protopinoid-type pittings. Phytogeographically, the fossil wood assemblage is characterized by an admixture of elements of both temperate Angaran (represented by wood specimens with moderately to well defined growth rings in their secondary xylem) and tropical–subtropical north subregion of the Cathaysian floras (with wood specimens lacking well-defined growth rings). Such a phytogeographically mixed fossil wood assemblage is interpreted to represent a transitional and complex climate condition between a cool temperate and tropical to subtropical zones, showing both seasonal variation and unstable climate conditions. Previously, similarly mixed floras have already been found to exist widely in northern China ranging in age from Early to Late Permian, but the mechanisms thought to be responsible for their formation were varied and remain controversial. In this study, the formation of these mixed Permian floras of North China is linked to the closure of the Tianshan–Hingan seaway coupled with the collision and amalgamation of Siberia with North China and the Tarim block, in a manner much like closing a pair of scissors with the closure of the seaway proceeding gradually and progressively from west to the east.

The simulation of Cr(VI) behavior in an unsaturated zone and aquifer, using a 3D experimental set-up were performed to illustrate the distribution, transport and transformation of Cr(VI), and further to reveal the potential harm of Cr(VI) after entering the groundwater. The result indicated that chromium(VI) was transported in the vertical direction, meanwhile, was transported in the horizontal direction under the influence of groundwater flow. The direction and distance away from the pollution source zone had great effect on the chromium(VI) concentration. At the sampling sites near the pollution source zone, there was a sudden increase of chromium(VI) concentration. The concentration of chromium(III) concentration in some random effluent samples was not detected. Chromium had not only transported but also had fraction and specie transformation in the unsaturated zone and aquifer. The relative concentration of residue fraction chromium was decreased with time. The content of Fe-Mn oxide fraction chromium was increased with time. The relative content of exchangeable and carbonate-bound fraction chromium was lower and the content variations were not obvious. Chromium(VI) (91-98%) was first reduced to chromium(III) rapidly. The oxidation reaction occurred later and the relative content of chromium(VI) was increased again. The presence of manganese oxides under favorable soil conditions can promote the reoxidation of Cr(III) to Cr(VI).

Returning crop residues into fields, either alone or in combination with inorganic fertilizer, is considered as a practical way to enhance soil fertility. However, information concerning the effects of crop residues and inorganic fertilizer application on water extractable organic matter (WEOM) in soil is scarce. The aim of this study was to examine the 10-year effect of corn residue (CR) return with or without the application of nitrogen, phosphorus, and potassium (NPK) fertilizer on the quantity and quality of WEOM in a black soil of northeast China by means of ultraviolet absorbance, fluorescence excitation--emission matrix, and derived spectroscopic indices. The application of NPK fertilizers and CR, alone or together, increased the content of total soil organic carbon (SOC), water extractable organic carbon (WEOC), and ratio of WEOC/SOC, with the sequence being NPK + CR > CR > NPK > CK. Compared with control treatment, the individual application of NPK fertilizer decreased the aromaticity of ...

Animal wastes are potential sources of natural and steroidal estrogen hormones into the environment. These hormones can be removed by microorganisms with induced enzymes. Two strains of 17β-estradiol-degrading bacteria (LM1 and LY1) were isolated from animal wastes. Based on biochemical characteristics and 16 S rDNA gene sequences, we identified strains LM1 and LY1 as belonging to the genus of Acinetobacter and Pseudomonas, respectively. Bacterial co-culture containing LM1 and LY1 bacterial strains could rapidly remove approximately 98% of E2 (5 mg L−1) within 7 days. However, strains LM1 and LY1 degraded 77% and 68% of E2 when they were incubated alone, respectively. More than 90% of 17β-estradiol (E2, ≤ 20 mg L−1) could be removed by bacterial co-culture. Low C/N ratio (1:35) was more suitable for bacterial growth and E2 degradation. The optimal pH for bacterial co-culture to degrade E2 ranged from 7.00 to 9.00. Coexisting sodium acetate, glucose and sodium citrate decreased E2 degradation in the first 4 days, but more E2 was removed when they were depleted. The growth of the bacterial co-culture was not significantly decreased by Ni, Pb, Cd or Cu at or below 0.8, 1.2, 1.6 or 0.8 mg L−1, respectively. These data highlight the usefulness of bacterial co-culture in the bioremediation of estrogen-contaminated environments.

Comprehensive and accurate vegetation monitoring is required in forestry and agricultural applications. The optical remote sensing method could be a solution. However, the traditional light detection and ranging (LiDAR) scans a surface to create point clouds and provide only 3D-state information. Active laser-induced fluorescence (LIF) only measures the photosynthesis and biochemical status of vegetation and lacks information about spatial structures. In this work, we present a new Multi-Wavelength Fluorescence LiDAR (MWFL) system. The system extended the multi-channel fluorescence detection of LIF on the basis of the LiDAR scanning and ranging mechanism. Based on the principle prototype of the MWFL system, we carried out vegetation-monitoring experiments in the laboratory. The results showed that MWFL simultaneously acquires the 3D spatial structure and physiological states for precision vegetation monitoring. Laboratory experiments on interior scenes verified the system&rsquo, s performance. Fluorescence point cloud classification results were evaluated at four wavelengths and by comparing them with normal vectors, to assess the MWFL system capabilities. The overall classification accuracy and Kappa coefficient increased from 70.7% and 0.17 at the single wavelength to 88.9% and 0.75 at four wavelengths. The overall classification accuracy and Kappa coefficient improved from 76.2% and 0.29 at the normal vectors to 92.5% and 0.84 at the normal vectors with four wavelengths. The study demonstrated that active 3D fluorescence imaging of vegetation based on the MWFL system has a great application potential in the field of remote sensing detection and vegetation monitoring.

The significant investigation was performed to establish a chemical baseline for snowfall in Northeast of China since there was no such record. The chemical and mineral composition of snowfall samples were evaluated in Jilin Province, Northeast China. The specific purposes of the present study are to characterize the chemical and mineral composition of melted snow-water samples and to identify the sources of atmospheric pollutants, as well as to investigate the spatial variability of melted snow-water chemistry in this region. Snowfall and aerosol samples were collected from Changchun city, Baicheng city, and Yanji city during November 2015 to March 2016. All the filtered (0.45 m) snow-water was analyzed for conductivity, pH, major cations (Na+, K+, NH4 +, Ca2+, Mg2+) and anions (F−, SO4 2−, Cl−, NO3 -, HCO3 -). The pH of these samples ranged from 6.01 to 7.10, with an average value of 6.44. The conductivity ranged between 17.50 μs cm-1 and 86.00 μs cm-1 with an average value of 55.0 μs cm-1. These parameters indicated high chemical concentrations in the snow-water. It was observed that Ca2+ and NH4 + were the major cations which accounted the concentration for 5.05% to 18.71% and 3.47 to15.54%. HCO3 - and SO4 2- were major anions which accounted the concentration for 23.41% to 38.49% and 21.10% to 35.24%, respectively. (SO4 2- + NO3 -)/ (Ca2+ + NH4 +) was 1.38. The organic carbon of particles in the snowfall was higher and the average content was 52.85 g kg-1. The size of the snow-water particles in the three Cities was mainly based on clay complexes ( (>200 μm)> (20-200 μm)> (2-20 μm). The dominant mineral of particles in the snow-water was quartz and feldspar, while clay mineral was composed of montmorillonite, illite, kaolinite and vermiculite. According to the above analyses, the possible sources of the particles in the snowfall should be soil and ground dust and co al-burning.