Search

Root pruning can impact the physiological functions of various plants, which influence phytoremediation. A series of root pruning treatments with different combinations of direction (two-side pruning and four-side pruning) and intensity (10, 25, and 33% pruning) were performed on Celosia argentea L. All two-side pruning treatments, regardless of intensity, decreased the dry biomass of the C. argentea roots at the end of the experiment relative to that of the control. However, the two-side-10% and two-side-25% pruning treatments stimulated the growth rate of the plant leaves significantly by 58.6 and 41.4%, respectively, relative to that of the control, and even offset the weight loss of the plant roots. Contrastingly, the two-side-33% pruning treatment reduced the biomass yield of leaves by 24.1%. For the four-side pruning treatments, the low intensity increased the dry weight of both the plant roots and leaves, while both decreased under high-intensity root pruning. The dry weight, Cd content, pigment level, and photosynthetic efficiency in the four-side-10% treatment were higher than those in the other treatments during the experiment. This study indicates that root pruning with a suitable combination of direction and intensity can positively influence the Cd removal ability of C. argentea. Our study suggests that a suitable root pruning pattern can significantly increase the phytoremediation effect of Celosia argentea L. Compared with chemical and biological regulation including plant hormone application, chemical reagent spraying, and endophytes inoculation which might introduce unpredictable risks into the ecological system, root pruning can be considered as an environmentally friendly physical trigger to modulate physiological features and to induce advantages in plants. This finding can be extrapolated into the real-world easily since root pruning is an established, convenient, and feasible method. We believe readers would be interested in this method. [ABSTRACT FROM AUTHOR]

Having studied the biomarker composition and maturity of dissolved hydrocarbons from Ordovician formation waters, the authors presented molecular geochemical evidence for the controversial origin of natural gases in central Ordos Basin. The dissolved hydrocarbons in Well Shan 12 and Well Shan 78 are relatively high in abundance of tricylic terpane, pregnane series and dibenzothiophene series and low in Pr/Ph (<2) and hopane/sterane ratios, indicating the source input of marine carbonates. In contrast, the dissolved hydrocarbons in Well Shan 81 are free from tricyelic terpane and pregnane series, with trace dibenzothiophene series and high Pr/Ph (3.27) and higher hopane/sterane ratios, which are the typical features of terrestrial organic matter. Furthermore, Well Shan 37 and Well Shan 34 are between the two situations, having a mixed source of marine carbonate and terrestrial organic matter. The maturity of biomarkers also supports the above suggestions. These results are consistent with the geological background and source rock distribution in this region. [ABSTRACT FROM AUTHOR]

Isotachophoresis results indicate that the total concentrations of organic acids in Ordovician formation waters range from 9.17 mg/L to 94.49 mg/L and are obviously higher than those of Permo-Carboniferous formation waters. But both of them have the same compositional characteristics, i.e., acetic acid > > formic acid > propanoic acid > butanoic acid. The total alkyl phenol contents of Ordovician formation waters range from 0.57 mg/L to 4.73 mg/L, averaging 1.77 mg/L. Among the samples for phenol detection, 47.06% samples contain less than 1.0 mg/L, 35.29% samples 1.0 - 3.0 mg/L, and only 17.65% samples more than 3.0 mg/L alkyl phenol. The concentrations of organic acids and alkyl phenols in the Majiagou formation waters are of obviously heterogeneous distribution. There are several areas where the concentrations of organic acids and phenols are high in central Ordos Basin. These organic acid- and phenol-high areas (organic acids >45 mg/L and phenols >20. mg/L) are consistent with natural gas reservoir enriched areas in central Ordos Basin. [ABSTRACT FROM AUTHOR]

Reservoir solid bitumens from the Permian to Triassic and potential source rocks in the northeastern Sichuan Basin were measured for elemental and stable carbon (δ 13 C) and sulfur (δ 34 S) isotopic compositions to determine the chemical and isotopic composition of non-TSR and TSR-altered solid bitumen and to develop proxies to reflect the extent of bitumen alteration by TSR. Non-TSR altered reservoir bitumen samples showed S/C atomic ratios ⩽0.03 and had δ 13 C values closer to Longtan Formation (P 3 l) kerogen than to the Lower Silurian and Cambrian kerogens, and δ 34 S values slightly more enriched than P 3 l kerogens. The TSR-altered solid bitumens have incorporated significant amounts of TSR-derived H 2 S resulting in S/C atomic ratios (0.047–0.074) and δ 34 S values (13.4–24.0‰) being significantly higher than those of the solid bitumen not altered by TSR (S/C: 0.013–0.030; δ 34 S: 5.8–9.6‰) and the potential source rock kerogen. The incorporation has produced a decrease in N/C ratio and negative shift of −2.7‰ in δ 13 C values that resulted from increasing TSR-H 2 S back reactions with 12 C-rich n -alkanes from the gas phase, soluble solid bitumen or paleo-oil to generate organic sulfur compounds such as ethanethiol that were incorporated into the solid bitumens, which is followed by further aromatization and polymerization. The solid bitumens show positive relationships of S/C ratios and δ 34 S values to the associated gas H 2 S/(H 2 S + ΣC 1–6 ) or TSR extents, and thus the S/C ratios and δ 34 S values can be used as proxies to reflect TSR extents. [ABSTRACT FROM AUTHOR]