A series of pot culture experiments are carried out to evaluate the effects of inoculation of arbuscular mycorrhizal fungi (AMF) Glomus versifome (G.v) B1 and Glomus mosseae (G.m) B2 in different weight ratios (A1, A2, A3) of coal mine complex substrates. The results show that the increasing rates of organic matter, total N, P, and K reach 8.86%, 5.26%, 18.66% and 3.16%. A2 is selected as the suitable covering soil and B2 (G.m) as the preponderant AMF. White clover is suitable in the coal mine reclamation. Through promoting plants roots growth and the transformation of insoluble nutrition element to available state, the inoculation of AMF increases the nutrition absorption of plants and organic content in the substrate, fertilizing the coal mine complex substrate in the coal mine reclamation. The combination of AMF and sludge is able to enhance the fertilizing of coal mine castoff.
The matching degree between agricultural water and land resources directly determines the sustainable development of regional agriculture. Based on climate data corrected by delta statistical downscaling from five global climate models (GCMs) in the Coupled Model Intercomparison Project Phase 6 (CMIP6) and a multi-model ensemble, this study simulated the runoff used by the Variable Infiltration Capacity (VIC-3L) model under four emission scenarios (SSP1-2.6, SSP2-4.5, SSP3-7.0, and SSP5-8.5) and analyzed the land use changing trend to obtain the matching degree between agricultural water and land resources. The results demonstrate that annual climate factors exhibit an increasing trend, and the average annual runoff was 2128.08–2247.73 × 108 m3, during 2015–2100 under the four scenarios. The area of farmland changed with an increased area of 4201 km2 from 1980 to 2020. The agricultural water and land resources would be well matched under the SSP1-2.6 and SSP2-4.5 scenarios in 2021–2100. However, the risks of mismatch would occur in the 2030–2040 and 2050–2060 periods under the SSP3-7.0 scenario, and the 2030–2040 and 2080–2090 periods under the SSP5-8.5 scenario. This study can provide insight into the scientific decision support for government departments to address the challenges of mismatching risks of agricultural water and land resources.
α-Fe2O3 nanowires deposited diatomite was prepared using a precipitation–deposition method with FeCl3 as metal source and (NH2)2CO aqueous solution as precipitating agent. Physicochemical properties of the samples were characterized by means of numerous techniques, and their efficiency for the removal of As(III) and As(V) was determined. It is found that the solution pH value, reaction temperature, reaction time, and FeCl3 concentration had effects on the α-Fe2O3 amount loaded on the diatomite. Parameters, such as adsorbent amount, adsorption time, adsorption temperature, pH value, and initial As(III) or As(V) concentration, could influence the As(III) or As(V) removal efficiency of the α-Fe2O3 nanowires/diatomite sample (prepared with a 8 wt% FeCl3 aqueous solution at pH = 4.5 and 50 °C for 35 h) for the removal of As(III) and As(V). Over the α-Fe2O3/diatomite sample at pH = 3.5, the maximal As(III) and As(V) adsorption capacities were 60.6 and 81.2 mg g−1, and the maximal As(III) and As(V) removal efficiency was 99.98 and 100%, respectively. The Langmuir model was more suitable for the adsorption of As(V), whereas the Freundlich model was more suitable for the adsorption of As(III). The adsorption mechanism of the sample was also discussed.
The enlarged oil-contaminated soils posed threat to soil environment and human health. Persulfate (PS) oxidation combined with bioremediation is a promising method to remediate petroleum-contaminated soil, systematical research on the impact of PS on indigenous bacteria as well as soil properties is still scarce. This study investigated the variation of total petroleum hydrocarbons (TPH), pH, cation exchange capacity (CEC), oxidation-reduction potential, electrical conductance, soil lipase activity (LIP), and structure of soil microbial community during 7 d 1%, 3% and 5% (w/w) PS oxidation combined 180 d microbial remediation. The result showed that the TPH removal of 1% PS oxidation combined bioremediation (BC1S0), oxidation combined natural attenuation (C1S0), and bioremediation alone (BS0) were 81.25%, 56.99%, and 75.17%, respectively. The LIP in BC1S0 reached 277.86 ± 56.81 μg pNP/(g soil × 10min) on 60 days, which was significantly higher (p < 0.01) than that of BS0 and C1S0, indicating that 1% PS or bioaugmentation can promote secretion of LIP, thus enhancing hydrocarbons degradation. While 3% and 5% PS excessive oxidation, with only about 40% TPH degradation, resulted in severe bacterial destruction and soil deterioration. Compared with the original soil, the abundance of Proteobacteria and Firmicutes phylum increased after oxidation and the Proteobacteria then increased while Firmicutes decreased during subsequent microbial remediation. The redundancy analysis showed that the main factors affecting BS0 and BC1S0 systems were pH, CEC, and LIP, which may indirectly influent TPH biodegradation by increasing the abundance of Immundisolibacteraceae sp., Comamonadaceae sp., and Acinetobacter sp. This study provides the theoretical basis and technical support for in-situ chemical oxidation integrated with bioremediation for petroleum hydrocarbon contaminated soils.
ACF/GO/PEI (activated carbon fiber/graphene oxide/polyethyleneimine) composite was fabricated by crosslinking reaction and characterized with Scanning electron microscope (SEM), N2 physical adsorption and Fourier transform infrared spectroscopy (FTIR). Furthermore, the adsorption behavior of ACF/GO/PEI composite for methyl orange (MO) from aqueous solution was investigated. The experimental results showed that the specific surface area of ACF/GO/PEI composite is 1013.6 m2/g and almost the same as that of original ACFs. However, with a larger fraction of mesopores, the pore structure of ACF/GO/PEI composite showed a significant change in comparison with that of original ACFs. Accordingly, ACF/GO/PEI composite indicated more excellent adsorptivity than ACFs. The tests also showed the adsorption capacity decreased with the increase in adsorbent mass and pH. The adsorption isotherm was fitted using both Langmuir and Freundlich adsorption models and the adsorption process was found to be well-described by Langmuir model. Moreover, the adsorption kinetics was discussed with pseudo-first-order, pseudo-second-order and intra-particle diffusion models and the results disclosed the kinetic data were well fitted with pseudo-second-order kinetic model and the adsorption rate was controlled by intra-particle diffusion and film diffusion. Thermodynamic parameters including ΔG, ΔH and ΔS showed that the adsorption process was a spontaneous, endothermic and increasing randomness process.
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